Patent Publication Number: US-11649603-B2

Title: Manhole rehabilitation system

Description:
RELATED APPLICATIONS 
     This application claims priority benefit of and is a Continuation of U.S. Ser. No. 16/690,027 filed Nov. 20, 2019, which claims priority benefit of U.S. Provisional Ser. No. 62/770,028 filed Nov. 20, 2018, each incorporated herein by reference. 
    
    
     BACKGROUND OF THE DISCLOSURE 
     Field of the Disclosure 
     This disclosure relates to the field of manhole assemblies forming a chamber allowing access to a cross pipe. The disclosure includes a method and apparatus for reinforcing and improving an existing manhole structure in place. 
     RELATED APPLICATIONS 
     U.S. patent application Ser. No. 15/946,643 (&#39;643) discloses a different manhole assembly, which is manufactured off site in sections, and then assembled on site. The base of the &#39;643 application comprises bell connectors or equivalents which are attached to pipes which terminate at the bell connectors. 
     BRIEF SUMMARY OF THE DISCLOSURE 
     Disclosed herein is a method for producing a manhole. In one example the method comprises the steps of:
         establishing an excavation below a ground level;   exposing external piping in the excavation;   removing a section of the external piping;   providing a non-structural base liner having surfaces defining pipe openings, an outer surface, an upper edge;   placing the base liner in the excavation, the laterally opposed pipe openings aligned with the external piping;   placing a channel pipe having opposing ends in the base liner, attaching the opposing ends of the channel pipe to the external piping in place of the removed section; wherein the channel pipe passes through the pipe openings;   the channel pipe having an open channel in the upper region thereof, the open channel forming a fluid conduit to the external piping;   placing a channel form/plug in the open channel, substantially sealing the open channel from entry of debris;   filling the base liner with a semi-fluid aggregate material such as concrete, grout, plaster, resin, etc.;   substantially surrounding the base liner with the semi-fluid aggregate material;   allowing the aggregate material to harden;   removing the channel form/plug;   sealing at least one riser liner to the upper edge of the base liner;   sealing a cone liner to an upper edge of the riser liner;   sealing a riser cap to the upper edge of the riser cone; and   disposing a volume of aggregate fill exterior of the base liner, riser liner, and cone liner.       

     The steps disclosed above in some applications is not dependent on the order presented above. Not all steps are required in all applications, nor is the method of installation limited to the order above. The external piping may be linear or non-linear. 
     The method may be implemented wherein the channel pipe is formed of a polymer such as HDPE (High-density polyethylene), ABS (acrylonitrile butadiene styrene), uPVC (unplasticized polyvinyl chloride), CPVC (post chlorinated polyvinyl chloride), PB-1 (polybutylene), PP (polypropylene), PE (polyethylene), 4.8 PVDF (polyvinylidene fluoride), uPVC (unplasticized polyvinyl chloride) Variants, PE RT (polyethylene resin), and equivalents. 
     The method may be implemented wherein the open channel is open greater than 90°, 140°, 170°, or 180° around the circumference of the channel pipe. 
     The method may be implemented wherein the channel plug is sacrificial. This meaning that the channel plug is destroyed when it is removed and not able to be used again. 
     The method may be implemented wherein the step of filling the base liner includes the step of filling the base liner up to an upper edge of the channel pipe. 
     The method may be implemented wherein the base liner, riser liner, and/or cone liner are formed of, or comprise FRP. The term FRP as used herein to include fiber reinforced plastic materials. Examples of which are given later in this disclosure. 
     The method may be implemented wherein the base liner, riser liner, and/or cone liner are non-structural. The term “non-structural” used in this context that the components do not provide sufficient support for the manhole, nor satisfy compression requirements of the manhole. Sufficient support and compression requirements of the manhole are satisfied by the aggregate fill once hardened. A manhole ring, and manhole cover supported by the hardened state aggregate fill, not the base liner, riser liner, nor cone liner. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         FIG.  1    is a front partial section view of one example of a completed manhole rehabilitation system. 
         FIG.  2    is a top perspective view of an early (e.g. first) stage of construction of the manhole rehabilitation system. 
         FIG.  3    is a top perspective view of another (e.g. second) stage of construction of the manhole rehabilitation system. 
         FIG.  4    is a top perspective view of another (e.g. third) stage of construction of the manhole rehabilitation system. 
         FIG.  5    is a top perspective view of another (e.g. fourth) stage of construction of the manhole rehabilitation system. 
         FIG.  6    is a top perspective view of another (e.g. fifth) stage of construction of the manhole rehabilitation system. 
         FIG.  7    is a top perspective view of another (e.g. sixth) stage of construction of the manhole rehabilitation system. 
         FIG.  8    is a top perspective view of another (e.g. seventh) stage of construction of the manhole rehabilitation system. 
         FIG.  9    is a top perspective view of another (e.g. eighth) stage of construction of the manhole rehabilitation system. 
         FIG.  10    is a top perspective view of another (e.g. ninth) stage of construction of the manhole rehabilitation system. 
         FIG.  11    is a top perspective view of another (e.g. tenth) stage of construction of the manhole rehabilitation system. 
         FIG.  12    is a side view of one component of the manhole rehabilitation system. 
         FIG.  13    is a top perspective view of another (e.g. eleventh) stage of construction of the manhole rehabilitation system. 
         FIG.  14    is a top perspective view of another (e.g. twelfth) stage of construction of the manhole rehabilitation system. 
         FIG.  15    is a top perspective view of another (e.g. thirteenth) stage of construction of the manhole rehabilitation system. 
         FIG.  16    is a top perspective view of another (e.g. fourteenth) stage of construction of the manhole rehabilitation system. 
         FIG.  17    is a side view of a riser liner component of the system shown in  FIG.  1   . 
         FIG.  18    is an enlarged view of the region  18  of  FIG.  17   . 
         FIG.  19    is an enlarged view of the region  19  of  FIG.  17   . 
     
    
    
     DETAILED DESCRIPTION OF THE DISCLOSURE 
     In the field of manholes great advances have been made over the past 1700 years to improve efficiency, reduce problems, reduce leakage into and out of sewer systems, and to improve the longevity of sewer systems. 
     Historically, a great number of manholes and other in-ground fluid conduits have been installed which deteriorate, have deteriorated, or are prone to leakage and failure. In many instances, it is required that these problematic manholes need to be repaired or replaced. Often the cost of replacement of such structures less than the cost of repair over time. Disclosed herein is a manhole rehabilitation system which may be utilized in several examples to provide a modern manhole where required. In some instances, the disclosed manhole rehabilitation system may be utilized interior of an existing manhole. In some instances, the disclosed manhole rehabilitation system may entirely replace existing manhole wherein the existing cross pipe is not entirely replaced. The cross pipe(s) commonly including at least one inlet pipe and at least one outlet pipe. 
     The term “manhole” used in this disclosure generally refers to a chamber extending from a cross pipe or conduit generally upward to a ground level. Commonly a manhole as the term is used in this disclosure comprises a base engaging a cross-pipe or cross pipes, a riser extending upward from the base, and a manhole cover. These components may be separate, or a unitary monolithic structure. The manhole cover or lid is commonly removable from the riser and allows access to the chamber. In many instances the chamber is large enough to fit an adult person may then enter the manhole to access the cross pipe for inspection, cleaning, or repair. Wherein the manhole cover is the component normally seen by most people the term manhole has become synonymous with the manhole cover, but the distinction is intended herein between the components forming the chamber and the manhole cover. 
     Looking to  FIG.  1    is shown one example of a manhole rehabilitation system  20 . As shown, the disclosed manhole rehabilitation system  20  forms a manhole  22 . 
     The manhole  22  of this example defines a chamber  24  which intersects a cross pipe  26  which may be in place prior to installation of the manhole  22 . The chamber  24  of the manhole  22  is defined by several components, including a base  28  intersecting the pipe  26 , a riser  30  extending upward from the base  28 , and a riser cap  32  optionally including the previously mentioned manhole cover  34  removably fitted to the riser cap  32 . 
     In  FIG.  1    are shown several liner components with an aggregate fill  36  (grout) formed there around. The combination of the liner components, with the aggregate fill  36  and an optionally removable outer form  38  in combination form the base  28  and riser  30 . Generally, the aggregate fill is poured into the space between the liner components and the outer form  38  and then hardens to a structural solid capable of supporting the weight of the manhole ring, manhole cover  34 , and components such as vehicles etc. which may be temporarily supported by the manhole ring and manhole cover  34 . 
     A more detailed description of the base  28 , riser  30 , and other components will follow a general description of the manhole rehabilitation system  20 . 
     Once the aggregate fill  36  has hardened, the riser cap  32  and other components may be installed to the riser  20  and hardened aggregate material  36 . This may be accomplished by attaching a plurality of blocks  40  or equivalent structural materials onto the top edge of the riser  30 . These blocks  40  may be supported by the aggregate fill  36  and in turn support the cap  32  and cover  34 . The blocks  40  may be hardened clay bricks, cinder blocks, pavers, or equivalent components. The riser cap  32  of the example shown having an outer surface  42  which prior to final installation of the aggregate  36  slides vertically  44  as the outer surface  42  of the riser cap  32  engages an optional gasket  46  on the top edge of the riser  30 . In this way, the riser  32  may be adjusted such that the top edge  48  of the riser cap  32  is substantially flush or level with the ground level  50 . 
     Thus, when installation is complete, the manhole cover  34  will also be substantially flush with the ground level  50 . As previously mentioned, the liner components are generally not structural in that they will not satisfy structural requirements of manholes. This is especially relevant when the manhole  22  is below a roadway. Such installations are required to support a vehicle driving across the manhole cover  34 . Thus, the aggregate fill  36 , riser  32  including blocks  40  and manhole ring  52  provides structural resistance or compression strength to the manhole  22 . In one example, the manhole ring  52  and manhole cover  34  are metallic such as cast iron, steel or other components well-known in the art of manholes. 
     The other components are easily described by explaining one example of an assembly and construction process shown in  FIG.  2   - FIG.  16   .  FIG.  2    shows an excavation has been formed in the ground exposing a surface  100 . The surface  100  may be an inner bottom surface of the excavation  102  or may be an equivalent surface such as the bottom of an existing manhole. In  FIG.  2    is shown an example wherein the excavation  102  (see  FIG.  1   ) comprises shoring  104  to maintain the shape of the excavation  102 . In one example, the shoring  104  forms the outer surface of a mold into which the aggregate fill  36  is poured the form the structural (compression resisting) portion of the manhole  22 . In the example shown in  FIG.  3   , an existing pipe or existing manhole  106  is utilized for the outer surface of the mold.  FIG.  2    and  FIG.  3    show examples of shoring  104  and optionally use of an existing manhole  106  as the outer surface of the mold. The shoring  104  and/or an existing manhole  106  are generally interchangeable and can be used for many examples of the manhole rehabilitation system  20  shown herein. 
       FIG.  2    also shows a base liner  110  having a bottom edge  112  resting upon the inner bottom surface  100 . The base liner  110  of this example also has an outer surface  114  and an upper edge  116  vertically opposed to the bottom edge  112 . As shown, there are one or more pipe openings  118  in the base liner  110  through which fluid flows into and out of the manhole  22 . To differentiate specific pipe openings and specific examples of general components, a numbering system is used herein utilizing an alphabetic suffix for specific examples. In this example a pipe opening is labeled  118  wherein specific examples of the pipe openings  118  such as shown in  FIG.  2    are labeled  118   a  and  118   b.    
     Looking to  FIG.  2    it can be seen that in this example a channel pipe  120  extends through both lateral sides of the base liner  110  through pipe openings  118 . The channel pipe  120  of this example has ends  123  ( 123   a ,  123 B) of the channel pipe  120  are exterior of the base liner  110 . Also, it can be seen that a portion of the channel pipe  120  has been removed interior of the base liner  110 , resulting in a surface  123  forming an upwardly open channel  124 . The channel  124  allows the fluid in the channel pipe  120  to freely flow through the channel pipe  120  while still allowing visual inspection of the flow through the channel pipe  120  and inspection upstream and downstream of the channel  124 . Looking to  FIG.  3    it can be seen that the excavation  102  has exposed an external pipe  122  which has been cut and a section removed to install the base liner  110  and channel pipe  120 . Cutting of the external pipe  122  and removal of a section thus forming separate external pipes  122   a  and  122   b . In one example, the channel pipe  120  is cut to an angle  126  of approximately 180° relative to the longitudinal axis  128  of the channel pipe  120  to form the surface  123 . In another example, the channel pipe  120  is cut to an angle  126  of greater than 170° relative to the longitudinal axis  128  of the channel pipe  120 , forming the surface  123  of the channel  124 . 
     The channel pipe  120  may then be connected to the external piping  122  through couplings which may include gaskets  152 , seals, welding, brazing, etc. It is generally desired that the connection between the channel pipe  120  and external piping  122  not leak allowing fluid out of the channel pipe  120 , nor cross pipes  122  into the surrounding ground. This sealing may be accomplished in many known methods. In  FIG.  3    and subsequent Figs. a system is shown wherein a sleeve section  150  slides laterally onto the external piping  122  and the channel pipe  120  with a gasket  152  overlapping the sleeve section  150  and external piping  122  or sleeve section  150  and channel pipe  120 . 
     Before continuing, and axes system  10  is disclosed herein as shown in  FIG.  2   . The axes system  10  comprising a vertical axis  12 , a transverse axis  14  and a lateral axis  16 . In addition, terminology is used where generic components use a numeric label, and specific components having similar structure may have alphabetic suffixes. For Example, gasket  152   a  is a specific gasket  152 . 
     In one example, looking to  FIG.  3   , a channel form  160  is placed into the channel  124 . The channel form  160  extending the length of the channel  124  and prohibiting aggregate fill or debris from entering into the channel  124  during the next stages of construction. In one example, the channel form  160  is formed of a malleable material to allow easy removal from the channel  124 . In another example, the channel form  160  may be rigid with outer surfaces sufficiently smooth to allow easy removal from the channel  124  following hardening of the aggregate material poured their around and hardened. In one example, the channel form  160  is sacrificial. It may in this sacrificial example be made of foam or other materials which are destroyed when removed from the channel  124  during later steps of construction. 
     Looking to  FIG.  4    is shown the channel form  160  placed into the open channel  124  ready for pouring of the aggregate fill into the base liner  110 . At this stage, it may be desired to put adhesive tape, or other material upon the upper edge  116  of the base liner  110  to ensure that this surface does not become filled or damaged by the aggregate fill as the aggregate fill is poured into the base liner  110 . 
     Looking to  FIG.  5    is shown a worker support  162  which may be set upon the upper edge  116  of the base liner  110 . In this position, a worker may stand upon the upper surface  164  of the worker support  162  as the aggregate fill is poured into the base liner  110  and smoothed, leveled, sloped, as beveled, or textured for a non-skid bench surface as desired. 
     Looking to  FIG.  6    can be seen that an aggregate fill  166  has been poured into the base liner  110 . The aggregate fill  166  when hardened thus forming a bench  168  upon which a user may stand when inspecting or repairing the channel  124  and or cross pipes  122 . Once the aggregate fill  166  has substantially hardened, the channel form  160  may be removed. The shape of the channel form  160  may enlarge the channel  124  as the surfaces of the aggregate fill  166  formed by the channel form  160  create a vertical or widened surface to the channel  124 . In some examples, it may be desired to retain the channel form  160  in the channel  124  drain remaining steps of construction to keep debris out of the channel  124 . 
     In one example, it may be desired to seal the benching surface  168  with a non-permeable and/or corrosive-resistant material to ensure that the aggregate fill  166  does not become permeated with deteriorating chemicals commonly found in sewage and groundwater. Such deteriorating chemicals may be present in the fluid flow through the channel  124 , especially in sewage and industrial applications. 
     In one example, the aggregate material is a grout comprising 3250 PSI high flow non-shrink fast set grout known in the art for similar applications. 
       FIG.  7    shows another stage of construction wherein a volume of non-hardened aggregate  176  is placed between the outer surface  172  of the base liner  110  and a containing surface  174  which may be the interior surface of the excavation  102 , the interior surface of shoring  104 , or equivalent structure. Once the aggregate  176  is cured to a hardened state an outer mold  38   a  may be placed thereupon, radially outward of the upper edge  116  of the base liner  110  and resting upon the aggregate  176 . In one example, alignment components  178  may be fitted to the aggregate  176  or other structure to align the outer mold  38   a  so as to have a center axis  180  on center with the center axis  182  of the base liner  110 . In one form, the outer mold  38   a  is a cylinder such as sold under the trade name Sono Tube®. 
     Looking to  FIG.  8    is shown another stage of construction which may be accomplished prior to installation of the outer mold  38   a  shown in  FIG.  7   . In  FIG.  8    a pouring support  184  is positioned within the base liner  110  where the aggregate fill  166  as shown in  FIG.  6    does not reach the upper edge  116  thus forming a lip contacting the pouring support  184 . Once the pouring support  184  is in place, a riser liner  200  having a top edge  230  may be placed on the upper edge  116  of the base liner  110  and seal thereto. The riser liner  200  having an inner surface contacting the radially outward surface of the pouring support  184 . The pouring supports  184  ensuring alignment of the riser liner  200  to the base liner  110 . Sealing of the riser liner  200  to the base liner  110  may be accomplished by an O-ring, semi-fluid sealant, or hardening sealant such as well-known in the art. If an adhesive tape or similar component was used to protect the upper edge  116 , this adhesive tape may be removed prior to installation of the riser  200 . As shown in  FIG.  1   , it can be seen that the bottom  202  of the riser liner  200  and gauges the top edge  116  of the base liner  110 .  FIG.  19    shows a similar connection at an upper edge  116  of a base liner  110 . In this example, the upper edge comprises an inner component  204  and an outer component  206  with a gap therebetween. The inner component  204  and the outer component  206  connect at a connection point  208 . As shown, the bottom edge  210  of a second section  212  such as another riser section fits into the space between the inner component  204  and the outer component  206 . A volume of sealant  214  may be disposed in the space so as to seal the base liner  110  to the second section  212 . The second section  212  may be a riser liner  200 , cone liner  220 , or other component. Similarly other connections between other liner components/sections may be similarly constructed. 
       FIG.  17    also shows a plurality of bridge anchors  222  ( 222   a - 222   d ) which further engage/mechanically bond the base liner  110  to the cured aggregate  176 . Similar bridge anchors  224  may be fitted to the riser liner  200  for a similar purpose to mechanically bond the riser liner  200  to the aggregate fill  36 . Similar bridge anchors  226  may be fitted to the cone liner  220  likewise to mechanically bond the cone liner  220  to the aggregate fill  36 . 
     Although in the examples shown only one riser liner  200  is shown, it can be appreciated that a plurality of riser liners  200  may be connected/stacked one upon the other to extend the vertical height of the manhole  22  such that the distance between the surface  100  and the ground level  50  is achieved when the blocks  40 , manhole ring  52  are included. 
     Looking to  FIG.  9   , the outer mold  30   8 A is not fully shown in this Fig. to more clearly show the internal components. In  FIG.  9   , the bottom edge  228  of the cone liner  220  is shown fitted to the upper edge  230  of the riser liner  200 . The cone liner  220  having an upper edge  221  which will connect to other sections in a later stage of assembly. This fitting of the cone liner  220  to the riser liner  200  may be accomplished in the same manner as that shown in  FIG.  19    and disclosed above using the same or similar structures such as shown in  FIG.  19   . 
     In one example, the cone liner  220  has a first diameter at the bottom edge  228  and a second, smaller diameter at an upper edge  232 . Such a reduction in diameter is known in the art of manholes and accomplished through an angled cone shaped device as shown here, a stepped cone, an arcuate cone, or other equivalent structures. 
     Looking to  FIG.  10    is shown the shared aggregate  176  forming part of the base assembly  242  with the outer mold  38  positioned thereupon as previously discussed. A riser liner  200  and cone liner  220  are installed as described. This riser liner  200  and cone liner  220  assembly forming the inner surface of a mold  234  into which is poured a volume of aggregate fill  236 . As shown in  FIG.  11   , a worker support  238  functionally equivalent to the worker support  162  may be utilized to allow a worker to correctly and properly form the upper surface  240  of the aggregate fill  236 . The aggregate fill being concrete or other materials formed of Portland cement and equivalent pourable materials that harden to a structurally supporting state. The aggregate fill  236  will in one example flow under the channel pipe  123  and thus support the weight of the channel pipe  123  and material flowing therein upon the surface  100 . In one example, the sides  161  of the channel form  160  result in a surface of the channel  124  formed of the aggregate fill  166  rising up to or above the edge of the channel pipe  120 . 
     Looking to  FIG.  14    is shown the base assembly  242  with the outer mold  38   a  and aggregate fill  236  removed to show the riser liner  200  and cone liner  220 . In this example, a telescopic collar tube (TAC)  244  fits inside the cone liner  220  as previously described. The gasket  46  sealing between these components. This TAC having an upper edge  246  which may rest upon the blocks  40  previously discussed in allows the manhole ring  52  to be adjusted to substantially align with the ground level  50 . 
       FIG.  15    shows the blocks  40  in position. It is understood by looking to  FIG.  1    that the blocks  40  rest upon the upper surface  248  of the aggregate fill  36  and not on the upper edge of the cone liner  220  in that the cone liner to learn  20  is generally not a structural component. 
     Looking to  FIG.  16    is shown the shoring  104  extending substantially to the ground level  50 . Thus, the region between the aggregate fill  36  and the shoring  104  may be filled with a backfill  250 . The shoring  104  may then be removed. In another example, the shoring  104  is removed prior to the backfill  250  being placed. 
     In one example, the base liner  110 , riser liner  200 , cone liner  220 , and collar tube  244  are formed of fiber reinforced plastic (FRP). FRP is well-known in the arts as fiberglass although the term fiberglass is generally synonymous with the fibers used, and thus confusing. An FRP construction is generally a resin impregnated fibrous material; with a hardener added to the resin such that when the combined resin/hardener cures the FRP material hardens to a rigid state. The fibers used may be fiberglass, carbon fiber or less commonly burlap or other materials. The resin may be a polyester resin which is common in the arts, or epoxy which is also common the arts or other partners. They may be one part or two-part although the two-part materials are more common. 
     One advantage of producing the base liner  110 , riser liner  200 , cone liner  220 , and collar tube  244  from an FRP material is that the same resin may be used as the sealant  214  used between adjoining sections. Thus, the sealant  214  will cure to a hardened state, rigidly securing the adjacent components to each other as a substantially unitary construction. 
     One installation sequence includes the steps of:
         Excavate and install shoring support. If utilities are found, they should be wrapped with Styrofoam or other protective apparatus.   Cut existing exterior pipes to the desired length.   Set base liner on the surface of the excavation.   Install channel pipe inside base liner extending through pipe openings.   Cut a channel opening in the channel pipe.   Connect the channel pipe to the existing exterior pipes.   Install channel form in the channel opening to keep aggregate and debris out of the channel pipe and to form a deeper concrete channel during grouting.   Install work platform (worker support).   Apply adhesive tape to upper edge of base liner to protect joint section from debris.   Grout inside of base liner with 3250 PSI high flow non-shrink fast set grout and build benching.   Remove work platform.   Apply aggregate exterior of base liner.   Install reinforcing dowels around the outer perimeter of the base liner if required.   Install inner pouring supports to inner edge of base liner.   Install one or more riser liners on to base liner using inner pouring supports to ensure alignment.   Apply resin to the connection between the base liner and the riser liner.   Install cone liner to the riser liner.   Apply resin to the connection between the cone liner and the riser liner.   Install work platform to upper edge of cone liner.   Apply aggregate exterior of base liner, riser liner, cone liner to upper edge of cone liner.   Install telescoping access collar to cone liner.   Install blocks and adhesive to upper surface of aggregate to support manhole ring and manhole cover.   Install cast iron manhole ring onto blocks.   Apply aggregate to remaining level from the top of cone to rim elevation after telescoping access cone, blocks, cast iron manhole ring are installed and leveled.   Remove the shoring from excavation.   Backfill excavation to rim/ground elevation.       

     In addition to the steps listed above: these general guidelines should be considered:
         Local codes may apply and should be consulted as applicable in manhole installation.   Correct manhole liner installation commonly requires proper connection between segments/components and/or host surface. Good placement of surrounding structural aggregate and proper handling are essential to prevent manhole damage and ensure long-term corrosion resistant service.   FRP manhole liners may be non-structural components. To restore or achieve the desired load rating class of the rehabilitated manhole, the engineer specified grout/aggregate material and optional steel reinforcing should be strictly followed.       

     In addition to the steps listed above: these general preparation steps should be considered:
         Exterior pipes penetrating as-built manhole walls should only be cut with prior consent of engineer or designer.   Cut and remove existing asphalt or concrete.   Excavate and remove flat top or cone section of manhole and remove surrounding material.   Remove all existing ladder rungs, obstacles and debris from existing manhole. Generally, do not cut pipes penetrating as-built manhole walls.   Clean manhole structure walls. Substantially remove all damaged/flaking/unsecured concrete/aggregate materials. This should be accomplished when possible without further damage to manhole structural walls.   Prevent any additional damage to as-built structure or surrounding infrastructure when demolishing and excavating.   If live flow in the exterior piping or manhole, channel should be bypassed.   In low flow applications, “flow thru” inflatable pipe plugs may be acceptable to use as the channel form/plug. If pipe plugs are used, complete blockage of flow will be required for both grouting of base liner and installation of internal pipe seals.   Remove existing interior components (i.e. pumps, grinders, guiderails, valves, etc.)   There should be no flow or process contents in the structure during rehabilitation work on the base. Flow may be restored during construction of Wall Liner segments, provided safety is not compromised.       

     In addition to the steps listed above: these general baseliner installation steps should be considered:
         The channel should be clean and devoid of flow in most applications.   Benching may be partially removed to allow a minimum of 50 mm [2″] (or as specified on project documents) spacing between the base liner and any existing concrete. Care is to be taken when removing the existing benching to prevent damage to the existing base.   The baseliner shall be lowered into position. The liner may be secured in position and fastened with anti-flotation connections to the existing manhole structure. In most applications, the upper edge of the baseliner should be level.   Alignments and level of channels, pipe penetrations and base skirt flange shall be checked. It is commonly recommended to dry fit the baseliner prior to the installation in order to determine the locations of the anti-floatation mountings.   The liner may be connected to existing pipes. Channel of baseliner may be supported during pouring with a matching EPS pouring support.   Pipe penetrations may be sealed with correctly sized inflatable plugs.   Aggregate conforming to specifications of current manhole standards is to be poured into the annular space between the baseliner and any existing structure. Grout may be poured up to 50 mm [2″] below the top of the base liner. Installer should ensure grout is free of voids and air pockets.   Let aggregate set/harden.   Remove mounting brackets and EPS channel support.   After application of aggregate, flow may be temporarily restored with “flow thru” pipe plugs and appropriate length connected hose provide flow does not adversely affect liner cleanliness or worker safety.   For installation of link pipe internal seal, area between as-built pipe and new baseliner must be clear of any/all obstructions.       

     In addition to the steps listed above: these general wall and cone liner installation steps should be considered:
         If base liner component is present, stack riser liner and cone liner segments as needed to fully erect the FRP manhole liner inside an existing manhole. Maintain FRP manhole liner plumb within the manhole throughout the stacking process and ensure that space between the FRP manhole liner and the existing wall is of sufficient thickness throughout the entire circumference, as specified. Establish resin connection between adjoining components.   If base liner component is not present, fully demolish invert and benching to obtain a solid, level aggregate surface at the bottom of the manhole for the first wall liner section. Bond the wall liner to the manhole base with an appropriate sealant, such as Sikaflex®, silicone, or equivalent. Stack remaining riser liner and cone liner components as needed to fully erect the FRP manhole liner inside the existing manhole. Maintain FRP manhole liner plumb within the manhole throughout the stacking process and ensure that space between the FRP manhole liner and the existing wall is of sufficient thickness throughout the entire circumference, as specified by the engineer. Establish resin connection between adjoining components.   If required to restore or achieve the desired load rating class of the rehabilitated manhole, steel reinforcing shall be installed in the annular space between the FRP Manhole liners and the manhole wall, as specified by the engineer.   The FRP manhole liner may be carefully grouted in place, with a high-flow grout/aggregate, from the bottom up, in lifts not exceeding 6′. Aggregate shall be consolidated to fill all pockets, seams and cracks within the existing wall.   If Baseliner component is not present, rebuild invert and bench as specified by the engineer.       

     In addition to the steps listed above: these general backfill steps should be considered:
         Backfilling may be done just as soon as the concrete (grout, aggregate) has hardened enough around the cone liner to provide sufficient support for manhole and fill. Native soil (or sand, in unstable areas), free of large stones, debris, or concrete chunks may be used for backfill. Backfill should be place evenly around manhole in 12″ maximum lifts and should be thoroughly tamped to 90% standard proctor density before the next layer is installed. Backfill material shall be subject to approval by the engineer.       

     In addition to the steps listed above: these general baseliner steps should be considered to bring the final installation to grade:
         Construct chimney on flat shoulder of manhole using precast concrete rings (blocks).   Insert FRP telescoping access tube into the gasketed FRP access collar.   Install casting per standard manhole construction methods.       

     In addition to the steps listed above: these general chela-up steps should be considered:
         Upon completion, the installer should clean up the work site and properly dispose of any excess material or debris.       

     In another installation example: 
     Exterior Surface: 
     The exterior surface may be finished with embedded aggregates and FRP bonding bridges to allow for adequate bonding with the surrounding aggregate once installed. The exterior surface should be free of blisters larger than 0.5″ in diameter, delamination and fiber show, except in the vicinity of FRP bonding bridges where fiber show may be acceptable. Gel-coat or paint or other coatings may not be allowed. 
     Interior Surface: 
     The interior surfaces of the base liner  110 , riser liner  200 , cone liner  220 , and/or collar tube  244  shall be resin rich with no exposed fibers. Interior surface shall be smooth for improved corrosion resistance and reduced sludge build-up. The surface should be free of crazing, delamination, blisters larger than 0.25″ in diameter, and wrinkles of 0.125″ or greater in depth. Surface pits shall be permitted up to 6/ft2 if they are less than 0.75″ in diameter and less than 0.0625″ deep. Voids that cannot be broken with finger pressure and that are entirely below the resin surface shall be permitted up to 4/ft2 if they are less than 0.5″ in diameter and less than 0.0625″ thick. Gel-coat shall be permitted on interior surfaces, no paint or other coatings are allowed. 
     Chemical Resistance: 
     FRP lined manholes demonstrate having sufficient corrosion resistance by passing the “Greenbook” 2009 edition (or later), Standard Specifications for Public Works Construction, Chemical Resistance Test (Pickle Jar Test). 
     Physical Properties: 
     All FRP liner material shall have the following physical properties when tested at 77° F.±5 degrees: 
     
       
         
           
               
               
               
               
               
             
               
                   
               
               
                 Property 
                 Standard 
                 Units 
                 Initial 
                 (Par. VI. F.) 
               
               
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
            
               
                 Density 
                 ASTM D792 
                 g/cm3 
                 1.02 
                   
               
               
                 Thickness 
                   
                 Mm 
                 3 min. 
                   
               
               
                 Tensile Strength 
                 ASTM D638 
                 psi 
                 7,000 
                 6,500 min. 
               
               
                   
                   
                   
                 min. 
                   
               
               
                 Hardness (Shore 
                 ASTM 
                   
                 95-97 
                 89-97 
               
               
                 “A”) 
                 D2240 
                   
                   
                   
               
               
                 Weight change 
                   
                   
                   
                 0.05% max. 
               
               
                 Flexural Strength 
                 ASTM D790 
                 Lbf 
                 124 avg. 
                   
               
               
                 Compressive 
                 ASTM D695 
                 psi 
                 13,000 
                   
               
               
                 Strength 
                   
                   
                   
                   
               
               
                 Ignition Loss 
                 ASTM 
                 % 
                  52 avg. 
                   
               
               
                   
                 D2584 
                   
                   
                   
               
               
                 Taber abrasion test 
                 ASTM 
                 % 
                 0.075 
                   
               
               
                 (weight loss) 
                 D4060 
                   
                   
                   
               
               
                   
               
            
           
         
       
     
     Tensile specimens may be prepared and tested in accordance with ASTM D412 using Die B. Weight change specimens shall be 1 IN by 3 IN samples. 
     All gaskets may have the following physical properties: 
     
       
         
           
               
               
               
               
             
               
                   
               
               
                 Property 
                 Standard 
                 Units 
                 Requirement 
               
               
                   
               
             
            
               
                 Chemical resistance: 
                 ASTM D543 
                 % % 
                 No weight loss No weight 
               
               
                 1N sulfuric acid 1N 
                 (at 24° C. for 48 
                   
                 loss 
               
               
                 hydrochloric acid 
                 hr.) 
                   
                   
               
               
                 Tensile Strength 
                 ASTM D412 
                 psi 
                 1,200 min. 
               
               
                 Elongation at Break 
                 ASTM D412 
                 % 
                 350 min. 
               
               
                 Hardness (Shore A) 
                 ASTM D2240 
                   
                 ±5 from the connector 
               
               
                   
                   
                   
                 manufacturer&#39;s specified 
               
               
                   
                   
                   
                 hardness 
               
               
                 Accelerated oven 
                 ASTM D573 
                 % 
                 Max 15% decrease in 
               
               
                 aging 
                 (at 70° C. for 7 
                   
                 tensile strength; Max 20% 
               
               
                   
                 days) 
                   
                 decrease in elongation 
               
               
                 Compression set 
                 ASTM D 395, 
                 % 
                 Max 25% decrease of 
               
               
                   
                 Method B (at 
                   
                 original deflection 
               
               
                   
                 70° C. for 22 hr.) 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
               
               
               
             
               
                   
               
               
                   
                   
                   
                 Increase of max 10% of 
               
               
                   
                 ASTM D471 (at 
                   
                 original weight (19 by 
               
               
                 Water absorption 
                 70° C. for 48 hr.) 
                 % 
                 25 mm specimen) 
               
               
                   
               
             
            
               
                 Ozone Resistance 
                 ASTM D1149 
                   
                 Rating 0 
               
               
                 Low temperature 
                 ASTM D2137 
                   
                 No fracture at −40° C. 
               
               
                 brittle point 
                   
                   
                   
               
               
                 Tear resistance 
                 ASTM D624, 
                 kN/m 
                 34 
               
               
                   
                 Die B 
               
               
                   
               
            
           
         
       
     
     While the present invention is illustrated by description of several embodiments and while the illustrative embodiments are described in detail, it is not the intention of the applicants to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications within the scope of the appended claims will readily appear to those sufficed in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods, and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the spirit or scope of applicants&#39; general concept. The invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein.