Abstract:
Provided is a restoration pipe pulling-in method which can easily determine whether pilling-in of a restoration pipe is possible wherein the restoration pipe has a diameter as much as large relative to a deteriorated drainage channel, and which can pulling a restoration pipe into a sewer pipe wherein the gap between the restoration pipe and the sewer pipe is shorter. The restoration pipe pulling-in method comprises preparing a dummy restoration pipe  30 ′ which imitates the restoration pipe; attaching a determination jig  10  for determining whether pulling-in of the restoration pipe is possible to an insertion-side leading end portion of the dummy restoration pipe  30 ′; pulling the dummy restoration pipe  30 ′ with the determination jig  10  into the existing pipe  1 ; after confirming completion of passing-through of the dummy restoration pipe  30 ′ with the determination jig  10 , attaching a pull-in jig to a leading end portion of the restoration pipe; and arranging the restoration pipe over an entire length of the existing pipe  1 , by inserting the restoration pipe with the pull-in jig, through an upper opening  2   b  of the existing pipe  1 , into the existing pipe  1 , and by pulling the pull-in jig with a wire.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a method for pulling in a restoration pipe to restore an existing pipe, by pulling a new resin restoration pipe into the existing pipe having a crack or a damage thereon, or having a reduced water tightness in a pipe joint portion thereof, due to earth pressure or repeated load caused by travel of vehicles or the like, or due to seismic vibrations, over a long time after the existing pipe was buried under the ground. 
       BACKGROUND ART 
       [0002]    In a sewer pipe having been buried under the ground for a long time, there arises a problem that the load carrying capacity is reduced to cause collapse of a road or the flow capacity becomes insufficient. 
         [0003]    A method and an apparatus for solving such problem are disclosed in Patent Literatures 1 and 2. 
         [0004]    A drainage pipe repairing apparatus described in Patent Literature 1 shown in  FIG. 17  forms a new resin drainage pipe inside a deteriorated sewer pipe. With the drainage pipe repairing apparatus, a pipe body can be formed in an existing pipe in a simple manner, without using construction facilities for excavating earth. 
         [0005]    In the case of the drainage pipe repairing apparatus, a resin pipe  50  (generally referred to as “corrugated pipe” or “waved pipe”) having flexibility is led out from a rotating drum  51 , then inserted, through a manhole  52  on the left side, into an existing sewer pipe  53  from one side thereof, and then pulled in, by a winch  54 , via a manhole  52  on the right side. In  FIG. 17 , the leading end of the resin pipe  50  has a cap  55  for the pulling-in, which is attached thereto, and the cap  55  has a wire  56  connected thereto. 
         [0006]    In a pipeline restoration method described in Patent Literature 2, a restoration pipe formed from a thermoplastic material so as to have an outer diameter smaller than the inner diameter of a sewer pipe is pulled, through a manhole, into the sewer pipe to be restored. Then, hot air of 100° C. or higher is sent into the restoration pipe to be enclosed therein to an appropriate extent, whereby the restoration pipe is heated to have an enlarged diameter, thereby being brought into close contact of it with the inner wall of the sewer pipe. 
         [0007]    The restoration pipe to be used in this pipeline restoration method is formed into a flatten shape in the diameter direction of the pipe when being pulled into the sewer pipe, and after the restoration pipe has been pulled into the sewer pipe, the shape of the restoration pipe is changed into a cylindrical shape with the hot air, and the diameter thereof is forcedly enlarged. In this manner, the restoration pipe is brought into close contact with the inner wall of the sewer pipe, whereby the inner wall of the sewer pipe can be lined. 
       PRIOR ART LITERATURE 
     Patent Literature 
       [0000]    
       
         Patent Literature 1: Japanese Laid-Open Patent Publication No. 2002-38581 
         Patent Literature 2: Japanese Laid-Open Patent Publication No. 2004-239403 
       
     
       SUMMARY OF INVENTION 
     Problems to be Solved by the Invention 
       [0010]    In a sewer pipe buried under the ground, a shift, a bend, or the like may occur at a connection portion thereof over a long time. When a restoration pipe is inserted into a sewer pipe having such a shift, a bend, or the like, in a case where degree of the shift or the bend is large, or an obstacle is present in the connection portion thereof, a problem arises that the restoration pipe is prevented from being pulled in even if the restoration pipe is flexible. 
         [0011]    In order to carry out safe and efficient pulling-in work for the entire length of the sewer pipeline, it is necessary to avoid the above problem. Thus, with the conventional method and apparatus, it cannot be helped to use a restoration pipe whose outer diameter is considerably smaller than the inner diameter of the sewer pipe. 
         [0012]    However, after such pipeline has been restored, there is a problem that the diameter of the sewer pipe has been considerably reduced, and thus, the draining ability is reduced to a great extent. Moreover, although not necessary in terms of the structure, due to a request or the like from a client, it may be necessary to perform post-treatment of injecting a filler into a gap, between the outer wall of the restoration pipe and the inner wall of the sewer pipe, that is caused when the restoration pipe was pulled into the sewer pipe. If such treatment is performed, it becomes actually impossible to restore the pipeline next time. 
         [0013]    In the case of the drainage pipe repairing apparatus described in Patent Literature 1, a rotating drum and a winch are needed to be set near manholes. In the case of the pipeline restoration method described in Patent Literature 2, a hot air generator and a pressurizer are needed to be set near a manhole. 
         [0014]    While the rotating drum and the winch, and the hot air generator and the pressurizer are set, the vicinity of the manhole is occupied by these apparatuses. However, there are cases where the vicinity of the manholes cannot be occupied. 
         [0015]    For example, in the case of a manhole provided in the middle of an intersection of fundamental roads with large traffic, if the vicinity of the manhole in the intersection is occupied even for a short time period, a big traffic jam is caused, and city functions are stopped. 
         [0016]    The restoration pipe to be used in the method of Patent Literature 2 has to be made thin due to the above-described configuration, and thus, it is difficult to secure a sufficient mechanical strength thereof. Therefore, the method of Patent Literature 2 would not be preferable for ensuring long-term stability and safety. 
         [0017]    The present invention has been made in consideration of the above problems in the conventional drainage pipe repairing methods as described above. A first object of the present invention is to provide a restoration pipe pulling-in method that allows a restoration pipe having a diameter greater than that of a conventional restoration pipe to be smoothly pulled into a sewer pipe, and to provide a restored pipeline. 
         [0018]    Associated with the first object, a subordinate object of the present invention is to provide a restoration pipe pulling-in method that can prevent occurrence of an inefficient situations in which, in the step of pulling in the restoration pipe, the restoration pipe becomes no longer able to be pulled in while being pulled in, and the restoration pipe that has been pulled in halfway has to be removed off, and a restoration pipe with a smaller diameter is newly pulled in. 
         [0019]    Moreover, a second object of the present invention is to provide a restoration pipe pulling-in method that allows a restoration pipe to be pulled in even when the vicinity of a manhole on the ground cannot be occupied. 
       Solution to the Problems 
       [0020]    The present invention relates to a restoration pipe pulling-in method for pulling, as a restoration pipe, a resin pipe having flexibility into an existing pipe, 
         [0021]    the method of the present invention comprises: 
         [0022]    a preparation step of preparing a dummy restoration pipe which imitates the restoration pipe; 
         [0023]    a determination jig attaching step of attaching a determination jig for determining whether pulling-in of the restoration pipe is possible to an insertion-side leading end portion of the dummy restoration pipe; 
         [0024]    a dummy pulling-in step of pulling the dummy restoration pipe with the determination jig into the existing pipe; 
         [0025]    a pull-in jig attaching step of attaching, after confirming completion of passing-through of the dummy restoration pipe with the determination jig, a pull-in jig to a leading end portion of the restoration pipe; and 
         [0026]    an arrangement step of arranging the restoration pipe over an entire length of the existing pipe, by inserting the restoration pipe with the pull-in jig, through an opening of the existing pipe, into the existing pipe, and by pulling the pull-in jig with a wire. 
         [0027]    In the present invention, the existing pipe may be a drainage channel connected between manholes, and 
         [0028]    the restoration pipe with the pull-in jig can be carried into one of the manholes through an upper opening thereof, and further inserted into the drainage channel through an opening of the drainage channel, and the pull-in jig can be pulled with the wire from the other manhole side. 
         [0029]    In the present invention, the restoration pipe pulling-in method preferably further comprises: 
         [0030]    a pull-back jig attaching step of attaching a pull-back jig to a rear end portion of the dummy restoration pipe, wherein 
         [0031]    in the dummy pulling-in step, when a failure of pulling-in of the dummy restoration pipe with the determination jig has occurred in the existing pipe, the dummy restoration pipe having the determination jig and the pull-back jig can be pulled back by a wire connected to the pull-back jig. 
         [0032]    In the present invention, the determination jig preferably includes: an insertion part having a conical shape; a cylindrical body part extended from a peripheral edge of the insertion part; and a cylindrical fixing part extended rearward from the cylindrical body part and having a reduced diameter relative to that of the cylindrical body part, and for fixing the dummy restoration pipe thereon. 
         [0033]    In the present invention, the cylindrical body part is preferably formed to have an outer diameter greater than an outer diameter of the restoration pipe. 
         [0034]    In the present invention, the determination jig preferably further includes an untwisting member inside the insertion part and the cylindrical body part. 
         [0035]    In the present invention, the restoration pipe pulling-in method preferably further comprises, before the dummy pulling-in step: 
         [0036]    a diagnosis step of causing a diagnosis jig for detecting a narrow site in the existing pipe to pass through the existing pipe; and 
         [0037]    an excavation step of excavating and widening the detected narrow site. 
         [0038]    In the present invention, the restoration pipe pulling-in method further comprises: 
         [0039]    a drum setting step of setting a drum, on which the restoration pipe is wound, near and above a most upstream manhole among manholes communicating with the existing pipe; 
         [0040]    a winch setting step of setting a winch above a most downstream manhole distanced from the most upstream manhole by at least two or more spans; and 
         [0041]    a connecting step of connecting a wire unwound from the winch to the pull-in jig, wherein 
         [0042]    in the arrangement step, by winding up the wire by the winch, the restoration pipe can be continuously pulled into the existing pipe extending for two or more spans. 
         [0043]    In the present invention, the existing pipe may be a sewer pipe, and the restoration pipe can be pulled into the existing pipe while sewerage can be in service. 
         [0044]    In the present invention, the restoration pipe passing through an intermediate manhole provided between the most upstream manhole and the most downstream manhole can be cut out along an inner wall surface of the intermediate manhole after the restoration pipe has been pulled therethrough. 
         [0045]    The present invention comprised a pipeline restored by the restoration pipe pulling-in method 
       Advantageous Effects of the Invention 
       [0046]    According to the restoration pipe pulling-in method of the present invention, with respect to an existing pipe to be restored, whether a restoration pipe can be pulled thereinto can be determined in a simple manner. Thus, a restoration pipe having a greater diameter than that of a conventional restoration pipe can be smoothly pulled into the existing pipe. 
         [0047]    According to the restoration pipe pulling-in method of the present invention, it is also possible to continuously restore an existing pipe over a plurality of spans (the length of an existing pipe connecting adjacent two manholes is defined as one span) while sewerage is in service. Therefore, even when the vicinity of a manhole on the ground cannot be occupied, a restoration pipe can be pulled in. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0048]      FIG. 1  is an explanatory view which illustrates a drainage channel to which a restoration pipe pulling-in method of the present invention is applied. 
           [0049]      FIG. 2  ( a ) to ( c ) are front views showing a bend, a gap, and a step occurred in drainage channels, respectively, and (d) is a plan view showing a horizontal shift. 
           [0050]      FIG. 3  ( a ) is a side cross-sectional view of a determination jig according to the present invention, and (b) is a right side view thereof. 
           [0051]      FIG. 4  ( a ) is a side cross-sectional view of a pull-in jig according to the present invention, and (b) is a right side view thereof. 
           [0052]      FIG. 5  ( a ) is a side cross-sectional view of another pull-in jig according to the present invention, and (b) is a right side view thereof. 
           [0053]      FIG. 6  is a front view showing a structure of a restoration pipe, with a portion thereof cut out, according to the present invention. 
           [0054]      FIG. 7  is an explanatory view which illustrates confirmation work performed by a dummy restoration pipe with a determination jig. 
           [0055]      FIG. 8  is an explanatory view which illustrates preparatory work in the restoration pipe pulling-in method. 
           [0056]      FIG. 9  is an explanatory view which illustrates restoration pipe pulling-in work. 
           [0057]      FIG. 10  is an explanatory view which illustrates a state where the pulling-in of the restoration pipe has been completed. 
           [0058]      FIG. 11  is an external view of a diagnosis jig  60  according to modification 1. 
           [0059]      FIG. 12  is a flow chart showing a procedure of pipe restoration work in modification 1. 
           [0060]      FIG. 13  is an explanatory view which illustrates a drainage channel to which a pipeline restoration method of the present invention is applied. 
           [0061]      FIG. 14  is an explanatory view which illustrates a prepared state for the pipeline restoration method according to the present invention. 
           [0062]      FIG. 15  is an explanatory view which illustrates the pipeline restoration method according to the present invention. 
           [0063]      FIG. 16  is an explanatory view which illustrates a completion state of construction by the pipeline restoration method according to the present invention. 
           [0064]      FIG. 17  is an explanatory view which illustrates a conventional drainage pipe repairing method. 
       
    
    
     DESCRIPTION OF EMBODIMENTS 
     Embodiment 1 
       [0065]    Hereinafter, the present invention will be described in detail based on an embodiment shown in the drawings. 
         [0066]    [1] Check on Drainage Channel 
         [0067]      FIG. 1  shows a drainage channel as a deteriorated existing pipe to which a restoration pipe pulling-in method of the present invention is applied. 
         [0068]    In  FIG. 1 , a drainage channel  1  is formed by a plurality of drainage pipes  1   a , made of concrete, being connected to each other and buried under the ground. One end portion of the drainage channel  1  is connected to, for example, a lower opening  2   a  provided at a lower portion of an upstream manhole  2 . The other end portion of the drainage channel  1  is connected to a lower opening  3   a  provided at a lower portion of a downstream manhole  3 . 
         [0069]    Before the above-described drainage channel  1  is to be restored, the drainage channel  1  is checked, at first. 
         [0070]    Specifically, a high-pressure washing vehicle is allocated, to wash the inside of the drainage channel  1  to be restored, with high-pressure water (which is referred to as a washing step). 
         [0071]    Next, a self-propelling camera is inserted into the drainage channel  1 , to search for the presence or absence of an obstacle, such as roots of a tree, that hinders pulling-in of a restoration pipe (which is referred to as a search step). 
         [0072]    As a result of the search, if it is necessary to remove an obstacle, an in-pipe working robot is introduced into the drainage channel  1 , and pre-processing such as removing the obstacle is performed (obstacle removing step). In  FIG. 1 , a water-stopping plug  4  for preventing sewerage from the upstream side from entering the drainage channel  1 , and a drum  5  on which the restoration pipe is wound are shown. 
         [0073]    [2] Confirmation Work During Pulling-in of Restoration Pipe 
         [0074]    There are some cases where the pipe body of a drainage pipe  1   a  has been bent (see portion A) in association with deterioration thereof as shown in  FIG. 2(   a ), a gap (see portion B) has occurred as shown in  FIG. 2(   b ), a step (vertical shift) (see portion C) has occurred as shown in  FIG. 2(   c ), and a horizontal shift (see portion D) has occurred as shown in the plan view of  FIG. 2(   d ). 
         [0075]    Thus, an allowable value is set for each of an angle of bend, a gap, a step, and a horizontal shift between drainage pipes. For example, allowable values are respectively set, such that the angle of bend between the drainage pipes  1   a  is about 10° or less, the gap is about 100 mm or less, the step is about 10 mm or less, the horizontal shift is about 10 mm or less. 
         [0076]    Each allowable value described above is set based on data indicating whether pulling-in is allowed or not, the data obtained through experiments in a plant or site operation, for each combination of a sewer pipe and a restoration pipe to be inserted in the sewer pipe. 
         [0077]    [3] Determination Jig 
         [0078]    A dummy restoration pipe is prepared by cutting a restoration pipe (which is described later) into a length of about 50 to 60 cm (which is referred to as a preparation step), and to one end thereof (which is referred to as an insertion-side leading end portion), a determination jig shown in  FIGS. 3(   a ) and  3 ( b ) is attached (which is referred to as a determination jig attaching step). 
         [0079]    Herein, a plurality of kinds of dummy restoration pipes  30 ′ (see  FIG. 7 ) are prepared by cutting a plurality of kinds of restoration pipes having different diameters, respectively. Moreover, a plurality of kinds of determination jigs having different diameters are prepared, and the plurality of kinds of determination jigs are attached to the insertion-side leading end portions of their corresponding plurality of kinds of dummy restoration pipes, respectively. 
         [0080]    It should be noted that in order to facilitate its pulling-back, a guide body (not shown) having the same shape as that of the determination jig can be provided to the rear end portion of each of the dummy restoration pipes. 
         [0081]      FIG. 3(   a ) is a side cross-sectional view of the determination jig.  FIG. 3(   b ) is a right side view thereof. Herein,  FIG. 3(   b ) shows a state where a rear-side eyenut  15  (which is described later) is removed. 
         [0082]    In  FIGS. 3(   a ) and  3 ( b ), a determination jig  10  includes a jig body  11  formed from a metal member made of iron or steel. The jig body  11  is composed of: an insertion part  11   a  having a conical shape; a cylindrical body part  11   b  extended from the peripheral edge of the insertion part  11   a ; and a cylindrical fixing part  11   c  extended rearward from the cylindrical body part  11   b  and having a reduced diameter relative to that of the cylindrical body part  11   b , and for fixing a dummy restoration pipe  30 ′ thereon, which are integrally formed together. 
         [0083]    The outer diameter φE of the cylindrical fixing part  11   c  is substantially equal to the inner diameter of the dummy restoration pipe, such that the dummy restoration pipe  30 ′ is fixed on the cylindrical fixing part  11   c  in close contact. 
         [0084]    The outer diameter φF of the cylindrical body part  11   b  is set to be slightly greater than the outer diameter of the dummy restoration pipe  30 ′. Specifically, φF is set to be about 1 mm greater than the outer diameter of the dummy restoration pipe  30 ′, so as to intentionally prevent free-passage thereof through the drainage channel  1  (so as to provide any slight restriction to free passage thereof). 
         [0085]    Herein, at the boundary portion between the cylindrical body part  11   b  and the cylindrical fixing part  11   c , a step  11   d  is provided. 
         [0086]    The axial length L of the cylindrical body part  11   b  is set to be, for example, about 40 to 60 mm. The axial length of the insertion part  11   a  is set to be substantially F/2. 
         [0087]    It should be noted that the dummy restoration pipe  30 ′ is formed so as to have an appearance corresponding to a corrugated pipe or a waved pipe, which is mentioned above. 
         [0088]    The cylindrical fixing part  11   c  is provided with a plurality of screw holes at equal intervals along the direction of a ridge reinforcement part spirally formed on the outer face of the dummy restoration pipe  30 ′. Thus, one end portion of the dummy restoration pipe  30 ′ can be detachably fixed to the cylindrical fixing part  11   c  with a plurality of screws. 
         [0089]    To the inside of the leading end portion of the determination jig  10 , a nut  12  is welded. A bolt  13  arranged along a center line CL of the jig body  11  is engaged, by thread, with the nut  12 . 
         [0090]    A front-side end portion of the bolt  13  protrudes from the leading end of the jig body  11  by a predetermined length. A front-side eyenut  14  is engaged, by thread, with a front end portion of the bolt  13 , thereby being integrated with the jig body  11 . 
         [0091]    The rear-side eyenut  15  is engaged, by thread, with a rear-side end portion (or a rear end portion) of the bolt  13 . By another nut  16  being fastened, the rear-side eyenut  15  that has been engaged by thread can be fixed. The length of the bolt  13  is adjusted such that the rear-side eyenut  15  is accommodated within the jig body  11 . 
         [0092]    [4] Pull-in Jig 
         [0093]    Next, the structure of a pull-in jig for pulling a restoration pipe into a drainage channel is described. 
         [0094]      FIG. 4(   a ) is a side cross-sectional view of the pull-in jig, and  FIG. 4(   b ) is a right side view thereof. The same components as those of the determination jig  10  shown in  FIG. 3  are denoted by the same reference numbers or characters, and the description thereof is omitted. 
         [0095]    In  FIG. 4 , as in the case of the determination jig  10 , a pull-in jig  20  is formed from a metal member made of iron or steel. An insertion part  21   a  having a hemispherical shape as well as a cylindrical fixing part  21   b  for fixing a restoration pipe thereon are integrally formed together, thereby forming a jig body  21 . 
         [0096]    The outer diameter φG of the insertion part  21   a  is set to be equivalent to or less than the outer diameter of the restoration pipe. In detail, the outer diameter φG is set to be equivalent to or less than the outer diameter of a ridge reinforcement part (or a ridge part) spirally formed on the outer face of the restoration pipe. Accordingly, the pull-in jig  20  is connected to the restoration pipe, and flush with the restoration pipe. 
         [0097]    Herein, in the boundary portion between the insertion part  21   a  and the cylindrical fixing part  21   b , a step  21   c  is formed. 
         [0098]    Moreover, in the cylindrical fixing part  21   b , a plurality of screw holes are provided at equal intervals along the direction of the ridge reinforcement part of the restoration pipe. One end portion of the restoration pipe can be detachably fixed on the cylindrical fixing part  21   b  with a plurality of screws. 
         [0099]      FIG. 5(   a ) is a side cross-sectional view of another pull-in jig, and  FIG. 5(   b ) is a rear view of the pull-in jig. The same components as those of the determination jig  10  shown in  FIG. 3  and those of the pull-in jig  20  shown in  FIG. 4  are denoted by the same reference numbers or characters, and the description thereof is omitted. 
         [0100]    In  FIG. 5 , as in the cases of the determination jig  10  and the pull-in jig  20 , a pull-in jig  25  is formed from a metal member made of iron or steel. An insertion part  26   a  having a hemispherical shape as well as a cylindrical fixing part  21   b  for fixing a restoration pipe thereon are integrally formed together, thereby forming a jig body  26 . 
         [0101]    The insertion part  26   a  is equivalent to the insertion part  21   a  shown in  FIG. 4 , that is provided, at the center thereof, with a hole for holding an untwisting member  27  therein. 
         [0102]    The untwisting member  27  is for relaxing twists that have occurred on the wire, and is held at a center portion of the jig body  26 . 
         [0103]    A nut  28  is welded to the outside of the rear end portion of the pull-in jig  25 . An eyebolt  29  is engaged, by thread, with the nut  28 , thereby being integrated with the jig body  26 . Herein, instead of the nut  28  and the eyebolt  29 , a bolt and an eyenut may be used. 
         [0104]    In a case where the pull-in jig  20  shown in  FIG. 4  is used to carry out the pulling-in, the pull-in jig  20  is used with an untwisting member additionally attached to the front-side eyenut  14  at the leading end of the pull-in jig  20 . 
         [0105]    On the other hand, in a case where the pull-in jig  25  is used to carry out the pulling-in, since the untwisting member  27  is hold in the pull-in jig  25 , the untwisting member does not protrude from the leading end of the pull-in jig  25 . Thus, the restoration pipe can be pulled into a position where the leading end of the pull-in jig  25  comes very close to a pulley  32  (see  FIG. 7 ), and thus, its work efficiency such as efficiency of removing work of the pull-in jig  25  or cutting work of the restoration pipe can be improved. 
         [0106]    [5] Restoration Pipe 
         [0107]      FIG. 6  is a front view showing the structure of the restoration pipe. 
         [0108]    In  FIG. 6 , a restoration pipe  30  is composed of a waved resin pipe having a straight pipe part  30   a  and a ridge reinforcement part  30   b  spirally formed on the outer face of the straight pipe part  30   a.    
         [0109]    With respect to the restoration pipe  30 , for example, the outer diameter is from 150 to 450 mm, the inner diameter is from 135 to 435 mm, the spiral pitch is from 8 to 40 mm, the height of a core in the ridge reinforcement part  30   b  is from 6 to 20 mm, and the width of the core is from 6 to 30 mm. 
         [0110]    With respect to the spiral pitch and the core width, which are mentioned above, when the spiral pitch is too narrow, the restoration pipe becomes difficult to be bent, and when the spiral pitch is too wide, the strength of the restoration pipe is lowered. Therefore, in order for the restoration pipe to have a sufficient easiness of bending and a sufficient strength, the width of the core is preferably set in a range of from 30 to 75% of the spiral pitch. Also, for the same reasons as described above, the thickness is preferably set in a range of from 10 to 50% of the core height. 
         [0111]    The straight pipe part  30   a  includes a lower wound soft resin layer  30   c  and an upper wound soft resin layer  30   d . On the outer face of the upper wound soft resin layer  30   d , the ridge reinforcement part  30   b  composed of a core covering part  30   e  and a hard resin core  30   f  is wound and disposed. 
         [0112]    The appearance of the restoration pipe  30  is similar to that of a conventional corrugated pipe. However, in the embodiment 1, since the strength of each of the components of the restoration pipe  30  is optimized, the restoration pipe  30  is formed as a self-standing restoration pipe. Therefore, it is not necessary to fill with a grout as a filler in the entirety of the gap between the inner wall of the drainage channel  1  and the outer wall of the restoration pipe  30 . It should be noted that a grout can be filled, as necessary, around only inlet and outlet portions of the restoration pipe  30 . 
         [0113]    [5-1] Lower Wound Soft Resin Layer 
         [0114]    The lower wound soft resin layer  30   c  can be formed from a thermoplastic resin excellent in chemical resistance, such as, for example, a vinyl chloride resin, a polyolefin resin, or a thermoplastic elastomer based on an olefin or a styrene, etc. 
         [0115]    [5-2] Upper Wound Soft Resin Layer 
         [0116]    The upper wound soft resin layer  30   d  can be formed from a thermoplastic resin having good adhesiveness to the lower wound soft resin layer  30   c  and being excellent in chemical resistance, such as, for example, a thermoplastic elastomer based on a styrene, an olefin, a nylon, a polyester, a polyamide, or a polystyrene. 
         [0117]    Herein, it is more preferable to blend an olefin-based resin with a thermoplastic elastomer as described above, since internal pressure, external pressure, flatness strength, compressive strength, and tensile strength can be improved. Examples of the olefin-based resin include PP, PE, and the like. 
         [0118]    [5-3] Core Covering Part 
         [0119]    The core covering part  30   e  is formed from a material that is the same as or similar to the material of the upper wound soft resin layer  30   d . The core covering part  30   e  is formed into a cylindrical shape during the production step of the restoration pipe  30 , and is heat-welded to the upper wound soft resin layer  30   d  when being spirally wound on the outer face of the upper wound soft resin layer  30   d , thereby being integrated therewith. 
         [0120]    [5-4] Core 
         [0121]    The hard resin core  30   f  is preferably formed from any one of PE (polyethylene), PP (polypropylene), PPE (polyphenylene ether), PPS (polyphenylene sulfide), PEI (polyetherimide), PAR (polyarylate), PES (polyethersulfone), PEEK (polyether ether ketone), PTFE (polytetrafluoroethylene), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), PA (polyamide), POM (polyacetal), a saturated polyester, and a polymer blend thereof. The hard resin core  30   f  is extruded into a bar shape, and is enclosed by the cylinder of the core covering part  30   e , while the core covering part  30   e  is being formed into a cylindrical shape. 
         [0122]    The hard resin core  30   f  is heat-welded with the core covering part  30   e  and the entire periphery of the hard resin core  30   f  is surrounded by the core covering part  30   e , whereby the hard resin core  30   f  is substantially integrated with the core covering part  30   e.    
         [0123]    Further, the hard resin core  30   f  and the core covering part  30   e  can be reinforced with a reinforcing material or a filler such as a glass fiber, a carbon fiber, an aramid fiber, a potassium titanate whisker, a talc, a mica, a calcium carbonate, a carbon black, a hydrous calcium silicate, or a magnesium carbonate. 
         [0124]    According to the restoration pipe  30  of the embodiment 1, the straight pipe part  30   a  is composed of the soft resin layers. Therefore, when the restoration pipe  30  is carried into the upstream manhole  2  from a drum  5  (see  FIG. 1 ), and then successively inserted into the drainage channel  1  from the inside of the upstream manhole  2 , the restoration pipe  30  can be bent at a necessary and sufficient curvature, thereby facilitating the construction. 
         [0125]    Herein, in the embodiment 1, the restoration pipe on which the ridge reinforcement part is spirally formed has been described. However, the ridge reinforcement part is not limited to the spirally formed one, and may be formed as concentric rings provided in a repeated and successive peak-valley shape in the axial direction of the pipe. 
         [0126]    [6] Restoration Pipe Pulling-in Method 
         [0127]      FIG. 7  to  FIG. 10  are explanatory views, each of which illustrates a restoration pipe pulling-in method. 
         [0128]    [6-1] Inspection by Using of Determination Jig 
         [0129]    In  FIG. 7 , before a restoration pipe is pulled into a drainage channel  1 , an inspection work as to whether the restoration pipe can be pulled into the drainage channel  1  (see  FIG. 1 ) is carried out, at first. Herein, the same components in  FIG. 7  as those in  FIG. 1  are denoted by the same reference numbers or characters, and the description thereof is omitted. 
         [0130]    The dummy restoration pipe  30 ′, to which the determination jig  10  (see  FIG. 3 ) is attached, is inserted into the drainage channel  1  from an upstream manhole  2 . 
         [0131]    To the front-side eyenut  14  of the determination jig  10 , one end of a wire  31  is connected. The other end of the wire  31  is to be wound-up by a winch  33  via a pulley  32  disposed in the downstream manhole  3 . 
         [0132]    Herein, to the rear-side eyenut  15  (see  FIG. 3 ) of the determination jig  10 , another wire  34  is additionally connected. In a case where the dummy restoration pipe  30 ′ with the determination jig  10  can not advance any longer due to a bend, a step, a shift or the like of the drainage channel  1 , the dummy restoration pipe  30 ′ with the determination jig  10  is to be pulled back by the wire  34 . Herein, in order to facilitate the pulling back, the rear end portion of the dummy restoration pipe  30 ′ can also be provided with a guide body (not shown) having the same shape as that of the determination jig  10 . 
         [0133]    Into the drainage channel  1  which includes various kinds of displacements shown in  FIG. 2 , the dummy restoration pipe  30 ′ with the determination jig  10  is inserted (which is referred to as a dummy pulling-in step). 
         [0134]    In the case of  FIG. 2(   a ), when the dummy restoration pipe  30 ′ with the determination jig  10  is to be passed through two drainage pipes  1   a  having an angle of bend in the connection part exceeding its allowable value, since the cylindrical body part  11   b  of the determination jig  10  is parallel with the inner wall of the drainage pipe  1   a  on the downstream side, the cylindrical body part  11   b  comes into contact with the inner wall thereof. Thus, the dummy restoration pipe  30 ′ with the determination jig  10  is prevented from smoothly passing therethrough. 
         [0135]    In the case of  FIG. 2(   b ), since the length of the cylindrical body part  11   b  of the determination jig  10  is set to be smaller than the allowable value of the gap, the cylindrical body part  11   b  gets stuck in the gap, and thus, the dummy restoration pipe  30 ′ with the determination jig  10  is prevented from smoothly passing therethrough. 
         [0136]    In each case of  FIG. 2(   c ) and  FIG. 2(   d ), when the step exceeds the allowable value, since there is little space in the gap between the outer wall of the trunk portion of the cylindrical body part  11   b  of the determination jig  10  and the inner diameter of the drainage pipe  1   a , the cylindrical body part  11   b  comes into contact with the end face of the drainage pipe  1   a  in the downstream side, and thus, the dummy restoration pipe  30 ′ with the determination jig  10  is prevented from smoothly passing therethrough. 
         [0137]    If the dummy restoration pipe  30 ′ with the determination jig  10  has smoothly passed through the drainage channel  1 , even if deformation has occurred in the sewer pipe, it is determined that the restoration pipe can be pulled into the drainage channel  1 . 
         [0138]    Herein, if the dummy restoration pipe  30 ′ with the determination jig  10  can not smoothly pass through the drainage pipes  1   a , the winding-up resistance of the winch  33  increases. Therefore, by monitoring the winding-up resistance, it is possible to identify the site preventing the dummy restoration pipe  30 ′ from passing therethrough. 
         [0139]    If, in the identified site, for example, a step (or a vertical shift) shown in  FIG. 2(   c ) has occurred, an in-pipe working robot is introduced in the sewer pipe to cut the inner wall of the drainage pipe  1   a  so as to ameliorate the step. Accordingly, the conditions that allow the restoration pipe to be pulled therein are get ready. 
         [0140]    [6-2] Pulling-in Preparation Work (or a Pulling-in Preparatory Step) 
         [0141]    In  FIG. 8 , a drum  5 , on which a restoration pipe  30  is wound, is disposed near an upper opening  2   b  of the upstream manhole  2 . To the leading end portion of the restoration pipe  30 , the pull-in jig  20  shown in  FIG. 4 , or the pull-in jig  25  shown in  FIG. 5  is attached (which is referred to as a pull-in jig attaching step). 
         [0142]    Further, above the upper opening  2   b , a guide roller apparatus  40  for smoothly sending the restoration pipe  30  into the upstream manhole  2  is set. 
         [0143]    Still further, around the bottom of the upstream manhole  2 , a guide apparatus  41  is set, which changes the advancing direction of the restoration pipe descending into the upstream manhole  2  toward the drainage channel  1 , i.e., into the horizontal direction. 
         [0144]    On the other hand, above the upper opening  3   b  of the downstream manhole, the winch  33  and the pulley  32  shown in  FIG. 7  are set. 
         [0145]    Accordingly, the pulling-in preparation for the restoration pipe  30  is completed. 
         [0146]    [6-3] Pulling-in Work (or an Arrangement Step) 
         [0147]    Next, in  FIG. 9 , the pull-in jig  20  is attached to the leading end portion of the restoration pipe  30  unwound from the drum  5 , and the restoration pipe  30  with the pull-in jig  20  is sent, through the upper opening  2   b , into the upstream manhole  2 . To the front-side eyenut  14  (see  FIG. 4 ) of the pull-in jig  20 , the wire  31  is connected, which was used when the dummy restoration pipe  30 ′ with the determination jig  10  was inserted and which has been unwound from the winch  33 . 
         [0148]    In this situation, when the winch  33  is driven in the winding-up direction, the restoration pipe  30  is pulled by the wire  31  in the direction of an arrow H in the drainage channel  1 . 
         [0149]    [6-4] Fixing Work (or a Finishing Step) 
         [0150]    After the restoration pipe  30  has passed through the drainage channel  1 , in a state where the leading end portion of the restoration pipe  30  protrudes by a predetermined length from the side of the downstream manhole  3 , the protruding portion thereof is cut out. 
         [0151]    Also, on the side of the upstream manhole  2 , the restoration pipe  30  extending from the drainage channel  1  is cut out. 
         [0152]    Next, with respect to the lower opening  2   a , of the upstream manhole  2 , being the inlet portion to the drainage channel  1 , as well as the lower opening  3   a , of the downstream manhole  3 , being the outlet portion from the drainage channel  1 , a pipe end finishing material (or a filler) is filled in the gap between the inner wall of the drainage channel  1  and the outer wall of the restoration pipe  30 , whereby both end portions of the cut restoration pipe  30  are fixed thereto. 
         [0153]    As the pipe end finishing material mentioned above, it is desirable to use a filler that can provide high water stopping performance and high strength after hardening, such as, for example, an epoxy resin or a mortar with a quick-setting admixture. 
         [0154]    Into the gap between the inner wall of the drainage channel  1  and the outer wall of the restoration pipe  30 , but excluding the gap at the inlet portion and the gap at the outlet portion, a back-filling material (or a filler) is injected, as necessary. 
         [0155]      FIG. 10  shows the restoration pipe  30  having been passed through and fixed in the drainage channel  1 . 
         [0156]    As the back-filling material, it is desirable to use a filler that is easy to fill, such as, for example, a grout obtained by mixing a mortar with a chemical solution, or a plastic foam such as a polyurethane foam obtained by mixing an isocyanate with a polyol. 
         [0157]    [7] Summary 
         [0158]    According to the pipeline restoration method of the embodiment 1, with respect to an existing pipe to be restored, whether a restoration pipe can be pulled thereinto can be determined in a simple manner. Thus, a restoration pipe having a greater diameter than that of the conventional restoration pipe can be smoothly pulled into the sewer pipe. 
         [0159]    Moreover, according to the pipeline restoration method of the embodiment 1, it is possible to prevent an occurrence of an inefficient situation in which, in the step of pulling the restoration pipe, the restoration pipe becomes no longer able to be pulled while the pulling-in operation, the restoration pipe that has been pulled in halfway has to be pulled back out, and then an alternative restoration pipe with a smaller diameter is to be newly subjected to the pulling-in operation. 
         [0160]    &lt;Modification 1&gt; 
         [0161]    In this modification 1, prior to the dummy pulling-in step of the embodiment 1, a diagnosis step and an excavation step are carried out. 
         [0162]    In the diagnosis step, in order to detect a narrow site in the drainage channel  1 , a diagnosis jig described later is caused to pass through the drainage channel  1 . In the diagnosis step, preferably, this work is performed with a camera introduced so as to follow the diagnosis jig and with the passing state of the diagnosis jig being checked by means of the camera. 
         [0163]    In the excavation step, an excavator is introduced into the narrow site, in the drainage channel  1 , that has been detected in the diagnosis step, and the inner wall of the drainage channel  1  is excavated so as to widen the narrow site. 
         [0164]    [1] Diagnosis Jig 
         [0165]      FIG. 11  is an external view of a diagnosis jig  60  according to the modification 1. In  FIG. 11 , the diagnosis jig  60  according to the modification 1 includes a jig body  61  formed from a metal member made of iron or steel. The jig body  61  is composed of an insertion part  61   a  having a conical shape, a cylindrical body part  61   b  extended from the peripheral edge of the insertion part  61   a , and a pull-back part  61   c  having a conical shape. 
         [0166]    The outer diameter φF′ of the cylindrical body part  61   b  is set to be slightly smaller than the outer diameter of the dummy restoration pipe  30 ′. Specifically, φF′ is set to be smaller, by about 35 mm, than the outer diameter of the dummy restoration pipe  30 ′, so as to easily pass through the drainage channel  1 . 
         [0167]    Herein, at the boundary portion between the insertion part  61   a  and the cylindrical body part  61   b , and at the boundary portion between the cylindrical body part  61   b  and the pull-back part  61   c , no step is provided in particular. 
         [0168]    From the point of workability, there is no problem if the axial length of the diagnosis jig  60  is less than or equal to the inner diameter of a manhole (which is 900 mm in the case of Japan). For example, an axial length L1 of the cylindrical body part  61   b  is set to be, for example, from about 250 to 500 mm, and an axial length L2 of the insertion part  61   a  and an axial length L3 of the pull-back part  61   c  are each set to be, for example, from about 200 to 300 mm. 
         [0169]    The diagnosis jig  60  further includes a plurality of roller parts  62  each protruding, from the surface of the cylindrical body part  61   b , by about 15 mm, for example. 
         [0170]    Each roller part  62  rotates upon bumping on the inner wall of the drainage channel  1 , while the diagnosis jig  60  is passing through the drainage channel  1 . Moreover, the roller part  62  is provided with a mechanism for withdrawing it inside the cylindrical body part  61   b  in accordance with a pressure applied by the inner wall. The roller part  62  is withdrawn to a great extent when it is passing through a narrow site in the drainage channel  1 , thereby causing a sensor built therein to respond. 
         [0171]    The diagnosis jig  60  includes an output means for outputting, for example, a sound, a light, or a signal. Upon receiving the response of the sensor, the output means provides an output, thereby being able to notify an operator that the diagnosis jig  60  is passing through a narrow site. The operator having received the output indicating that the diagnosis jig  60  is passing through the narrow site can recognize the position of the diagnosis jig  60  by means of, for example, the length of the wire  31  wound by the winch  33 , and can record the position. 
         [0172]    The leading end portion of the insertion part  61   a  has an eyenut  63   a  engaged by thread therewith. 
         [0173]    The leading end portion of the pull-back part  61   c  has an eyenut  63   c  engaged by thread therewith. 
         [0174]    [2] Procedure of Pipe Restoration Work 
         [0175]      FIG. 12  is a flow chart showing a procedure of the pipe restoration work in the modification 1. 
         [0176]    The procedure of the pipe restoration work is described below with reference to  FIG. 12 . 
         [0177]    (1) A high-pressure washing vehicle is allocated, to wash the inside of the drainage channel  1  to be restored, with high-pressure water (which is referred to as a washing step). 
         [0178]    (2) A self-propelling camera is introduced into the drainage channel  1  to search for the presence or absence of an obstacle, such as a root of a tree, that hinders pulling-in of the restoration pipe (which is referred to as a search step). 
         [0179]    (3) If it is necessary to remove an obstacle, an in-pipe working robot is introduced into the drainage channel  1 , and pre-processing such as removing an obstacle is carried out (which is referred to as an obstacle removing step). 
         [0180]    (4) The diagnosis jig  60  is caused to pass through the drainage channel  1  to detect a narrow site in the drainage channel  1  (which is referred to as a diagnosis step). Herein, it should be noted that this diagnosis step may be carried out simultaneously with the search step (2) described above. 
         [0181]    (5) An excavator is introduced into the narrow site detected in the diagnosis step, and the inner wall of the drainage channel  1  is excavated and widened such that the narrow site is widened (which is referred to as an excavation step). Herein, it should be noted that this excavation step may be carried out simultaneously with the obstacle removing step. 
         [0182]    (6) The dummy restoration pipe  30 ′ is prepared (which is referred to as a preparation step). 
         [0183]    (7) The determination jig  10  is attached to the leading end portion of the dummy restoration pipe  30 ′ at the insertion-side (which is referred to as a determination jig attaching step). 
         [0184]    (8) The dummy restoration pipe  30 ′ with the determination jig  10  is pulled into the drainage channel  1  (which is referred to as a dummy pulling-in step). 
         [0185]    (9) After completion of the passing-through of the dummy restoration pipe  30 ′ with the determination jig  10  has been confirmed, the pull-in jig  20  or  25  is attached to the leading end portion of the restoration pipe  30  (which is referred to as a pull-in jig attaching step). 
         [0186]    (10) A restoration pipe with the pull-in jig is introduced into the drainage channel  1  and the pull-in jig  20  or  25  is pulled with a wire, whereby the restoration pipe  30  is arranged over the entire length of the drainage channel  1  (which is referred to as an arrangement step). 
         [0187]    (11) Portions of the restoration pipe  30  that are protruding from the drainage channel  1  are cut out, and a pipe end finishing material is filled into the gaps, whereby both end portions of the cut restoration pipe  30  are fixed thereto (which is referred to as a finishing step). 
         [0188]    [3] Summary 
         [0189]    According to the pipeline restoration method of the modification 1, in a case where there are a plurality of narrow sites in the drainage channel  1 , by only causing the diagnosis jig  60  to pass therethrough once in the diagnosis step, all of the narrow sites therein are recognized. Therefore, by carrying out the diagnosis step and the excavation step before carrying out the dummy pulling-in step, it is possible to greatly reduce the work load of pulling back again the dummy restoration pipe  30 ′ with the determination jig  10  that had been pulled in halfway in the dummy pulling-in step, and thus, the work-efficiency can be increased. 
       Embodiment 2 
     [1] Check on Drainage Channel 
       [0190]      FIG. 13  shows a drainage channel as a deteriorated existing pipe to which the pipeline restoration method of the present invention is applied. 
         [0191]    In  FIG. 13 , a drainage channel  201  is formed by a plurality of drainage pipes  201   a , made of concrete, being connected to each other and buried under the ground. One end portion of the drainage channel  201  is connected to, for example, a lower opening  202   a  provided at a lower portion of a most upstream manhole  202 . The other end portion of the drainage channel  201  is connected to a lower opening  203   a  provided at a lower portion of a downstream manhole  203 . 
         [0192]    Before the drainage channel  201  described above is to be restored, the drainage channel  201  is checked, at first. 
         [0193]    Specifically, a high-pressure washing vehicle is allocated near the downstream manhole  203 , to wash the inside of the drainage channel  201  with high-pressure water (which is referred to as a washing step). 
         [0194]    Next, a self-propelling camera (not shown) is introduced into the drainage channel  201 , to search for the presence or absence of an obstacle, such as root of a tree, that hinders the pulling-in of a restoration pipe (which is referred to as a search step). 
         [0195]    As a result of this search, if it is necessary to remove the obstacle, an in-pipe working robot is introduced into the drainage channel  201 , and pre-processing such as removing the obstacle is carried out (which is referred to as an obstacle removing step). Herein, in  FIG. 13 , a water stopping plug  204  for preventing sewerage from the upstream side from entering the drainage channel  201 , and a drum  205  on which the restoration pipe is wound up are shown. Herein, it should be noted that if conditions of the flow rate not greater than 0.8 m/s or the depth of water not greater than 3 cm are satisfied, the restoration pipe can be pulled while the drainage channel  201  is in service, without using the water stopping plug  204 . Herein, it should be noted that in a case where the drainage channel is to be restored over a plurality of spans, the same checking step is carried out for all the spans of the drainage channel to be restored. 
       [2] Restoration Pipe 
       [0196]    The structure of the restoration pipe in the embodiment 2 is similar to that of the restoration pipe  30  in the embodiment 1 shown in  FIG. 6 . 
         [0197]    In the embodiment 2, since each of the components of the restoration pipe  30  is optimized so as to attain both of the strength and the flexibility, the restoration pipe  30  is formed as a self-standing restoration pipe. Therefore, after the restoration pipe  30  has been pulled into the drainage channel  201 , it is not necessary to carry out a step of heating the restoration pipe  30  to enlarge the diameter thereof so as to bring the restoration pipe  30  into close contact with the inner wall of the drainage channel  201 . Therefore, if the drainage channel  201  is restored by using of the restoration pipe  30  having the above structure, any hot air generator/pressurizer for heating the restoration pipe  30  to enlarge the diameter thereof is not necessary either. 
         [0198]    In a case where the restoration pipe  30  has been pulled into the drainage channel  201  shown in  FIG. 13 , a grout obtained by mixing a mortar with a chemical solution can be filled as a back-filling material, as necessary, into the small gap between the inner wall of the drainage channel  201  and the outer wall of the restoration pipe  30 . The back-filling material is not limited to the grout described above, and a plastic foam such as a polyurethane foam obtained by mixing an isocyanate with a polyol can be used as the back-filling material, for example. 
         [0199]    According to the restoration pipe  30  of the present embodiment, since the straight pipe part  30   a  is formed from soft resin layers, when the restoration pipe  30  is carried into the most upstream manhole  202  from the drum  205  (see  FIG. 13 ), and then continuously inserted into the drainage channel  201  at the inside of the most upstream manhole  202 , the restoration pipe  30  can be bent at a necessary and sufficient curvature, thereby facilitating the construction. 
       [3] Pulling-in of Restoration Pipe 
       [0200]    [3-1] Pulling-in Preparation (or a Pulling-in Preparatory Step) 
         [0201]    With reference to  FIG. 14 , an object of the present invention is to continuously restore the drainage channels  201  and  201 ′ from the most upstream manhole  202  to a most downstream manhole  206  which is distanced from the most upstream manhole  202  by at least two or more spans. 
         [0202]    The drum  205  on which the restoration pipe  30  is wound up is disposed near an upper opening  202   b  of the most upstream manhole  202  (which is referred to as a drum setting step). To the leading end portion of the restoration pipe  30 , a pull-in jig  211  is attached. 
         [0203]    Herein, it should be noted that the drainage channel  201  connects the most upstream manhole  202  and the manhole  203  which is located downstream to the manhole  202 . The drainage channel  201 ′ connects the manhole  203  and the most downstream manhole  206 . 
         [0204]    Further, above the upper opening  202   b  of the most upstream manhole  202 , a guide roller apparatus  220  for smoothly sending the restoration pipe  30  into the most upstream manhole  202  is set. 
         [0205]    Further, around the bottom of the most upstream manhole  202 , a guide apparatus  230  is set, which changes the advancing direction of the restoration pipe  30  descending in the most upstream manhole  202  toward the drainage channel  201 , i.e., into the horizontal direction. 
         [0206]    On the other hand, a winch  240  above the upper opening  206   b  of the most downstream manhole  206 , and a pulley  241  are set (which is referred to as a winch setting step). Accordingly, the pulling-in preparation for the restoration pipe  30  is completed. A lower opening  206   a  is provided at a lower portion of the most downstream manhole  206 . 
         [0207]    As described above, it is sufficient that those facilities which are set above the manholes to the drainage channel  201 ,  201 ′ to be restored include only the drum  205  and the winch  240  which do not need any large space. 
         [0208]    [3-2] Pulling-in of Restoration Pipe (or an Arrangement Step) 
         [0209]    With reference to  FIG. 15 , the pull-in jig  211  is attached to the leading end portion of the restoration pipe  30  unwound from the drum  205 , and the restoration pipe  30  with the pull-in jig is sent through the upper opening  202   b  into the most upstream manhole  202 . To the pull-in jig  211 , a wire  240   a  unwound from the winch  240  which is set above the most downstream manhole  206  is connected (which is referred to as a connecting step). 
         [0210]    In this state, when the winch  240  is driven in the winding-up direction, the restoration pipe  30  is pulled by the wire  240   a  in the direction of the arrow H in the drainage channel  201 . 
         [0211]    Accordingly, the restoration pipe  30  is pulled into the drainage channel  201  which is connected to the most upstream manhole  202  and the intermediate manhole  203 , and then, continuously pulled into the drainage channel  201 ′ which is connected to the intermediate manhole  203  and the most downstream manhole  206 . 
         [0212]    [3-3] Fixing Work (or a Finishing Step) 
         [0213]    After the restoration pipe  30  has passed through the drainage channel  201 ′, in a state where the leading end portion of the restoration pipe  30  protrudes by a predetermined length from the lower opening  206   a  of the most downstream manhole  206 , the protruding leading end portion is cut out. 
         [0214]    With respect to the restoration pipe  30  passing through the intermediate manhole  203 , a portion A extending across the manhole is cut out, and the cut ends of the restoration pipe  30  are processed along the inner wall surface of the intermediate manhole  203  (so as to be substantially flush with the inner wall surface). 
         [0215]    Also, with respect to the restoration pipe  30  pulled into the most upstream manhole  202 , the restoration pipe  30  is cut such that the cut end thereof is substantially flush with the inner wall of the most upstream manhole  202 . 
         [0216]    Next, with respect to the lower opening  202   a  of the most upstream manhole  202 , each of the lower openings  203   a  of the intermediate manhole  203 , and the lower opening  206   a  of the most downstream manhole  206 , a pipe end finishing material is filled in the gap between the inner wall of the drainage channel  201  and the outer wall of the restoration pipe  30 , whereby each of the end portions of the cut restoration pipe  30  is fixed thereto. 
       [4] Summary 
       [0217]    The restoration pipe to be used in the pipeline restoration method of the present invention is produced at a plant as a self-standing pipe having a cylindrical shape. Therefore, the step of heating/hardening/cooling the restoration pipe at site can be omitted, and the construction time can be shortened by a great extent. With a conventional resin restoration pipe, heating/hardening at site is required, and thus, countermeasures to remove odor have to be taken. However, with the pipeline restoration method of the present invention, such countermeasures need not be taken. 
         [0218]    Further, the pipeline restoration method of the present invention is not a type in which the diameter of the restoration pipe is enlarged to bring the restoration pipe into close contact with the inner wall of the drainage channel, and thus, is also advantageous in that the restoration pipe can be pulled in while the sewerage is in service. 
         [0219]      FIG. 16  shows the drainage channels  201  and  201 ′ restored by the pipeline restoration method of the present invention. 
         [0220]    In the above embodiment, an example where the drainage channels  201  and  201 ′ extending over two spans are to be restored has been explained. However, the present invention is not limited to the case of the two spans, and can be applied to drainage channels extending over two or more spans. 
         [0221]    Embodiment 1, modification 1, and embodiment 2 can be combined as appropriate, as long as they are compatible. 
         [0222]    The present application claims conventional priority based on Japanese Patent Application No. 2012-121465 filed on May 29, 2012, and Japanese Patent Application No. 2012-121466 filed on May 29, 2012. The entirety of the disclosure of Japanese Patent Application No. 2012-121465 filed on May 29, 2012 and the entirety of the disclosure of Japanese Patent Application No. 2012-121466 filed on May 29, 2012 are incorporated herein by reference. 
       INDUSTRIAL APPLICABILITY 
       [0223]    The pipe guiding apparatus, the pipe inserting system, and the pipe restoration system of the present invention can be widely and appropriately applied when pipes buried under the ground, such as the main pipe and branch pipes of a drainage pipe buried under the ground, are to be restored. 
       DESCRIPTION OF THE REFERENCE NUMBERS OR CHARACTERS 
       [0000]    
       
           1  drainage channel (or existing pipe) 
           1   a  drainage pipe 
           2  upstream manhole 
           2   a  lower opening 
           2   b  upper opening 
           3  downstream manhole 
           3   a  lower opening 
           3   b  upper opening 
           4  water stopping plug 
           5  drum 
           10  determination jig 
           11  jig body 
           11   a  insertion part 
           11   b  cylindrical body part 
           11   c  cylindrical fixing part 
           11   d  step 
           12  nut 
           13  bolt 
           14  front-side eyenut 
           15  rear-side eyenut 
           16  another nut 
           20  pull-in jig 
           20  jig body 
           21   a  insertion part 
           21   b  cylindrical fixing part 
           21   c  step 
           25  pull-in jig 
           26  jig body 
           26   a  insertion part 
           27  untwisting member 
           28  nut 
           29  eyebolt 
           30  restoration pipe 
           30   a  straight pipe part 
           30   b  ridge reinforcement part 
           30   c  lower wound soft resin layer 
           30   d  upper wound soft resin layer
         30   e  core covering part     
           30   f  hard resin core 
           30 ′ dummy restoration pipe 
           31  wire 
           32  pulley 
           33  winch 
           34  another wire 
           40  guide roller apparatus 
           41  guide apparatus 
           60  diagnosis jig 
           61  jig body 
           61   a  insertion part 
           61   b  cylindrical body part 
           61   c  pull-back part 
           62  roller part 
           63   a  eyenut 
           63   c  eyenut 
           201  drainage channel 
           201 ′ drainage channel 
           201   a  drainage pipe 
           202  manhole 
           202   a  lower opening 
           202   b  upper opening 
           203  manhole 
           203   a  lower opening 
           204  water stopping plug 
           205  drum 
           206  manhole 
           206   a  lower opening 
           206   b  upper opening 
           211  pull-in jig 
           220  guide roller apparatus 
           230  guide apparatus 
           240  winch 
           240   a  wire 
           241  pulley