Abstract:
Revealed herein is a system and method for monitoring continuity between adjacent barrier members. Each barrier member has a first edge defining a first connector and an opposed second edge defining a second connector. The second connector is adapted to cooperatingly engage a corresponding first connector of an adjacent barrier member. The system comprises detectable bodies along the first connector of the barrier member and a detector locatable along the second connector of the adjacent barrier member. The detector detects the proximity of the detectable bodies. The method comprises inserting a first barrier member into a soil formation, engaging the second connector of a second barrier member with the first connector and inserting the second barrier member into the soil formation adjacent to the first barrier member while utilizing the detector to verify engagement of the first and second connectors.

Description:
BACKGROUND OF THE DISCLOSURE 
     1. Field of the Disclosure 
     The present disclosure relates to barrier walls in general and in particular to a method and apparatus for monitoring the below surface connection of adjacent barrier members forming a subterranean barrier. 
     2. Description of Related Art 
     In the field of geotechnical engineering, it is frequently necessary to physically isolate one area in a soil formation from an adjacent area for a variety of purposes. These purposes may include providing either a temporary or a permanent retaining wall, or may be for the purpose of isolating contaminants in one of those areas of soil from the other. One known method of providing such isolation is to insert successive panels into the soil formation between the two areas so as to form a continuous barrier therebetween. In the case of remediation work where the purpose is to contain and remove contaminants from the soil of one of the areas, it is frequently necessary to ensure that the barrier created by such panels does not have significant gaps therebetween which may allow the contaminants to escape. 
     One common method of inserting such panels into the ground is to vertically orient the panel above the surface of the soil formation and apply sufficient pressure to the top of the panel so as to forcibly insert the panel into the soil formation. Successive panels may be thereafter similarly inserted into the soil formation with a slidable interconnection between the two adjacent panels to assure continuity. 
     A difficulty with present methods of inserting remediation panels into soil formations is their susceptibility to encountering large boulders or other subsurface objects. It is well known that encountering such subsurface objects may cause the panel to buckle or otherwise deform. Buckling of one remediation panel may cause the connector of that panel to disengage or unzipper from the corresponding connector of an adjacent panel. The resulting unzippered connection will no longer contain contaminants or other fluids thereby compromising the barrier. 
     Previous methods of detecting and analyzing the integrity of a connection between adjacent panels have not been satisfactory. In particular, Applicant is aware of U.S. Pat. No. 5,497,097 to Walling et al. The system of Walling et al. utilizes electrical contacts on interlocking panels to detect connection between the two panels. However, the apparatus of Walling et al. may be prone to not detecting proper connection between adjacent panels should some other material interposed between the electrical connectors. Additionally, the apparatus of Walling et al. may falsely indicate proper connection between adjacent panels in the presence of salt water or other electrolytic fluids due to the electrical fluid conducing electricity between the two electrical panels. 
     SUMMARY OF THE DISCLOSURE 
     According to a first embodiment of the present disclosure there is disclosed a system for monitoring continuity between adjacent barrier members. Each barrier member has a first edge defining a first connector and an opposed second edge defining a second connector. The second connector is adapted to cooperatingly engage a corresponding first connector of an adjacent barrier member. The system comprises at least one detectable body locatable along the first connector of said barrier member and a detector locatable along the second connector of the adjacent barrier member. The detector is adapted to transmit a proximity signal in response to detecting proximity to the detectable bodies. 
     The system in one form may further comprise an indicator adapted to receive the proximity signal from the detector wherein the indicator is further adapted to provide indicate the receipt of the proximity signal to a user. The indicator and detector may have a conductor therebetween for transmitting the proximity signal from the detector to the indicator. 
     The detectable bodies may comprise a plurality of detectable bodies distributable along the first connector. The detectable bodies may comprise magnets wherein the detector may comprise a magnetic proximity switch. The system may further comprise a longitudinal seal locatable within the second connector wherein the longitudinal seal includes the detector. 
     According to a further embodiment there is disclosed an apparatus for forming a barrier wall. The apparatus comprises a barrier member having a first edge defining a first connector and an opposed second edge defining a second connector. The second connector is adapted to engage a corresponding first connector of an adjacent barrier member. The apparatus further comprises at least one detectable body locatable along the first connector of the barrier member and a detector located along the second connector. The detector is adapted to transmit a proximity signal in response to detecting proximity to the detectable body. 
     The apparatus may further comprise an indicator adapted to receive the proximity signal from the detector wherein the indicator is further adapted to provide indicate the receipt of the proximity signal to a user. The indicator and detector may have a conductor therebetween for transmitting the proximity signal from the detector to the indicator. 
     The detectable bodies may comprise a plurality of detectable bodies distributed along the first connector. The detectable bodies may comprise magnets wherein the detector may comprise a magnetic proximity switch. The detectable bodies may be embedded in the first connector. 
     The first and second connectors may be slidably engageable with each other. The first connector may comprise a male connector wherein the second connector may comprise a female connector. The male connector may comprise an elongated flange extending along the first edge wherein the female connector may define a c-shaped opening corresponding to the size and shape of the male connector. The apparatus may further comprise a longitudinal seal locatable within the c-shaped opening wherein the longitudinal seal includes the detector. 
     The second connector may have a longitudinal passage parallel to the second edge of the barrier member wherein the detector is adapted to be located within the longitudinal passage. The longitudinal passage may comprise a longitudinal bore. The detector may be slidably locatable within the longitudinal passage. The detector may be securable to the second connector with an adhesive. 
     According to a further embodiment there is disclosed a method for forming a barrier wall. The method comprises inserting a first barrier member into a soil formation. The first barrier member has a first edge defining a first connector having at least one detectable body. The method further comprises slidably engaging a second connector of a second barrier member with the first connector and inserting the second barrier member into the soil formation adjacent to the first barrier member while utilizing a detector associated with the second connector to detect proximity of the at least one detectable body to verify engagement of the first and second connectors. 
     According to a further embodiment there is disclosed a method for verifying a connection between adjacent barrier members. Each barrier member has a first edge defining a first connector and an opposed second edge defining a second connector. The second connector is adapted to engage a corresponding first connector of an adjacent barrier member. The method comprises providing at least one detectable body along the first connector, slidably moving a detector adapted to detect proximity of the detectable bodies within a longitudinal passage along the second connector of the adjacent barrier member and providing a proximity signal in response to the detector detecting proximity to the detectable bodies. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In drawings which illustrate embodiments wherein similar characters of reference denote corresponding parts in each view, 
         FIG. 1  is a front elevation view of a barrier wall being formed in a soil formation utilizing interlocking barrier members according to a first embodiment. 
         FIG. 2  is a perspective view of a section of the barrier member of  FIG. 1 . 
         FIG. 3  is a cross-sectional view of the connection between the adjacent barrier members of  FIG. 1  taken along the line  3 - 3 . 
         FIG. 4  is a cross-sectional view of the barrier members of  FIG. 3  decoupled from each other. 
         FIG. 5  is a cross-sectional view of the connection between the adjacent barrier members of  FIG. 1  taken along the line  3 - 3  according to an alternative embodiment. 
         FIG. 6  is a perspective view of a barrier member of  FIG. 1  showing a plurality of spaced out detectable bodies. 
         FIG. 7  is a cross-sectional view of the connection between the adjacent barrier members of  FIG. 1  taken along the line  3 - 3  according to an alternative embodiment. 
         FIG. 8  is a cross-sectional view of the connection between the adjacent barrier members of  FIG. 1  taken along the line  3 - 3  according to an alternative embodiment. 
         FIG. 9  is a cross-sectional view of the connection between the adjacent barrier members of  FIG. 1  taken along the line  3 - 3  according to an alternative embodiment of the present invention. 
         FIG. 10  is a cross-sectional view of the connection between the adjacent barrier members of  FIG. 1  taken along the line  3 - 3  according to an alternative embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a barrier wall is shown generally at  10  being formed in a soil formation  8 . The barrier wall  10  comprises a plurality of barrier members  12  inserted into the soil formation  8  adjacent to and interlocked with each other so as to form a continuous barrier wall  10 . The barrier wall  10  may, by way of non-limiting example be a sheet piling wall wherein the barrier members comprise impermeable sheets. Barrier members  12 , such as barrier piling sheets, for use in forming barrier walls in soil formation  8  are known in the art. Methods of inserting such barrier member are also known in the art, such as, by way of non-limiting example, by utilizing known pile driver methods such as drop hammers, vibratory hammers or plate tampers and excavators, utilizing a mandrel or digging a trench to receive the barrier members  12 . As illustrated in  FIG. 1 , the barrier wall  10  may be formed by inserting a first barrier member  12   a  into the soil formation and thereafter inserting a second barrier member  12   b  adjacent to and slidably interlocked with the first barrier member  12   a.    
     With reference to the first barrier member  12   a , in one form each barrier member comprises a body having a substantially rectangular outline defined by top  14 , bottom  16  and first and second side edges,  18  and  20 , respectively. As illustrated in  FIG. 2 , the barrier member  12  may comprise a sheet of material having a variety of cross section profiles as are commonly known in the art. For example, by way of non-limited example, the barrier member  12  may have a substantially planar, z-shaped, a double z-shape, u-shaped or c-shaped cross section profile. As illustrated in  FIG. 1 , the top and bottom edges  14  and  16  are substantially parallel to each other. Furthermore, the first and second side edges  18  and  20  are substantially parallel to each other and substantially perpendicular to the top and bottom edges. The first edge  18  has a first connector  22  disposed therealong while the second edge  20  has a second connector  24  disposed therealong. As further described below, the first and second connectors  22  and  24 , are adapted to cooperate with corresponding first and second connectors of adjacent panels. The barrier members  12  may be formed of any known material in the art. Barrier members may be formed of metal, such as steel or aluminium, resins such as vinyl, polyvinyl chloride (PVC) or other known plastics, or composite materials such as fibreglass or carbon fibre by way of non-limiting example. 
     Turning now to  FIG. 3 , a cross-sectional view of a connection between adjacent first and second barrier members  12   a  and  12   b  in one form is illustrated. As illustrated, the first connector  22  of the second barrier member  12   b  is interlocked with the second connector  24  of the first barrier member  12   a . In the embodiment illustrated in  FIG. 3 , the first connector  22  comprises an elongate flange  23  extending along the length of the first edge  18  of the barrier member. The flange  23  of the first connector  22  has front and rear surfaces,  34  and  32 , respectively. The second connector  24  comprises a c-shaped channel  30  extending along the second edge  20 . The c-shaped channel  30  is defined by first and second opposed partitions,  26  and  28 , respectively adapted to surround the flange  23  and bear against the rear surface  32  of the first connector so as to retain the flange within the c-shaped channel  30 . 
     As illustrated in  FIG. 2 , the first and second connectors  22  and  24  extend along the first and second edges  18  and  20  of the barrier member. It will therefore be appreciated that the first connector  22  in one form is adapted to be longitudinally slidable within the second connector  24 . Adjacent first and second barrier members  12   a  and  12   b  may be connected by first interlocking the second connector  24  of the first barrier member with the first connector  22  of the second barrier member. The first barrier member  12   a  may then be moved in a direction generally indicated at  9  in  FIG. 1  parallel to the second barrier member until the first and second barrier members  12   a  and  12   b  form a continuous barrier wall  10 . Successive barrier members  12  may then be added to lengthen the barrier wall  10 . 
     The first connector  22  in one form includes at least one detectable body  40 . As illustrated in  FIG. 3 , the detectable bodies  40  are embedded in the front face  34  of the flange. It will be appreciated that the detectable bodies  40  may also be embedded within the flange  23  below the surface thereof or secured to the surface of the flange. The second connector  24  includes a longitudinal bore  42  therein. The longitudinal bore  42  is sized to receive a detector  70  (shown in  FIG. 6 ). The detector  70  is adapted to detect the proximity of the detectable bodies  40  in the first connector  22 . 
     Turning now to  FIG. 4 , the first and second connectors  22  and  24  are illustrated in a de-interlocked arrangement. As illustrated, the detector  70  located within longitudinal bore  42  has an effective range indicated generally at  50  having a radius  52 . The range  50  of the detector  70  is selected such that only detectable bodies  40  located within the c-shaped channel  30  will be detected while detectable bodies  40  outside of the c-shaped channel will not be detected. Accordingly, it will be appreciated that the detector  70  may be utilized to detect when the first connector  22  is correctly interlocked with the second connector  24 . For other embodiments illustrated and described below, similar ranges  50  for the detector  70  should be selected to ensure that the detectable bodies  40  are only detected when the first and second connector are properly interlocked. 
     The detectable bodies  40  may comprise any known body that is readily detectable based upon proximity by a corresponding detector  70 . The detectable bodies  40  may be formed of magnets, metallic bodies, active or passive Radio Frequency Identification (RFID) tags, magnetic metals or a radioactive material by way of non-limiting example. It will be appreciated that many other detectable materials may also be utilized. Applicant has found that magnets are particularly useful as the detectable bodies  40 . In such embodiments, the detector  70  may be a magnetic proximity switch having a reed switch located within the longitudinal bore  42 . It will also be appreciated that a reed sensor, reed relay or any other known magnets field switch device may be utilized as well. For embodiments utilizing RFID, magnetic metals, or radioactive materials, the corresponding detectors may be an RFID antenna, a metal detector or a particle detector such as a Geiger counter. 
     As illustrated in  FIG. 5 , according to an alternative embodiment of the present invention, the c-shaped channel  30  may optionally include a longitudinal seal  60  located therein. In this embodiment, the c-shaped channel  30  may be modified or enlarged so as to accommodate the longitudinal seal. The longitudinal seal  60  may include the longitudinal bore  42  therein. It will be appreciated that the longitudinal seal  60  may permit the retrofitting of the present invention to existing barrier members  12 . In operation, the c-shaped channel  30  of an existing barrier member  12  may be enlarged by known methods, such as, by way of non-limiting example, machining, grinding or plastic deformation to a size sufficient to accept both the first connector  22  and the longitudinal seal  60 . It will also be appreciated that the first connector  22  may also be correspondingly reduced in size by similar methods to permit both the first connector  22  and the longitudinal seal  60  to be located within the c-shaped channel  30 . It will be appreciated that the longitudinal seal  60  may also have the detector  70  cast integrally with it or have it otherwise formed with the detector. By way of non-limiting example, the longitudinal seal may also be formed by applying a volume of a caulking, grout, or cured rubber to the c-shaped channel  30  before the barrier members  12  are connected together. The detector  70  may be covered by any of these materials to form a seal in the c-shaped channel  30 . It will also be appreciated that the detector may be secured to any surface of the second connector  24  so as to enable it to properly detect the proximity of the detectable bodies  40 . For example, the detector may be secured to the exterior surface of the second connector  24  at a location where the second connector joins with the barrier member  12   a  as generally indicated at  54  in  FIG. 5 . 
     The longitudinal seal  60  may assist in the sealing of the connection between the first and second connectors  22  and  24 . It has been found that hydrophilic seals may be particularly useful although any other type of known seal may be utilized as well. The seal  60  may also be hydrophobic or may be optionally formed of grout, cured rubber or any other type of applied material. In such embodiments, the applied material may be placed within the c-shaped channel  30  prior to connecting with the adjacent barrier member. 
     Turning now to  FIG. 6 , a perspective view of a barrier member  12  is illustrated having a plurality of detectable bodies  40  applied to the first connector  22 . The plurality of detectable bodies  40  may be arranged along the first connector in a regular array at predetermined intervals. The system according to one embodiment of the present invention may therefore be utilized to determine if the entire length of the connection between the first and second connectors is properly interlocked. The detectable bodies  40  may be secured to the surface of the first connector  22 . Optionally, the detectable bodies  40  maybe embedded within the first connector  22 . In some embodiments, a user may drill or otherwise remove material from the first connector  22  so as to form a cavity  79  therein. The user may then locate and secure the detectable bodies  40  within the cavities  79 . It will also be appreciated that the detectable bodies  40  may be cast internally or at the surface of the barrier member  12  during formation of the barrier member. The barrier member  12  may also be cast or otherwise formed with cavities included in a size sufficient to receive the detectable bodies  40 . It will be appreciated that for embodiments in which only one detectable body  40  is utilized, the location of the detectable body  40  should be selected to be substantially adjacent to the bottom  16  of the barrier member  12 . 
     The barrier member  12  may also include an indicator  74  secured thereto in communication with the detector  70 . The indicator  74  may be in communication with the detector  70  through a communication conductor  72 . It will be appreciated that other methods of communication between the detector  70  and indicator  74  may also be useful as well such as radio frequency or infrared. The indicator  74  may be secured to the barrier member  12  as illustrated or may be mounted to an adjacent structure or held by a user. As illustrated, the detector  70  may be inserted into the longitudinal bore  42  in the direction generally indicated at  68 . It will be appreciated that many known methods of inserting the detector  70  may be utilized including a push rod, or by utilizing a wirepuller. In some embodiments, it will be appreciated that the detector  70  may be moveable both in direction  68  and a reverse direction so as to enable a user to selectively check the interconnection of the first and second connectors corresponding to each of the plurality of detectable bodies  40 . 
     The indicator  74  indicates to a user that the detector  70  has detected the proximity of a detectable body. The indicating means may include, by way of non-limiting example, a light, a noisemaker such as a siren or a horn. As illustrated in  FIG. 6 , the indicating means is a light  76  although any other known method of indicating may also be used. In some embodiments, the indicator may communicate a signal to be received by a corresponding receiver so as to permit the collection of data in a computer or the like. As illustrated in  FIG. 6 , the barrier member may also include indication marks  78  corresponding to the known locations of the detectable bodies on a corresponding barrier member. The indication marks  78  may be utilized to indicate to a user when a detectable body  40  is expected to be detected during installation of one barrier member  12  with another. In operation, the user may locate the detector  70  at a known depth within the longitudinal bore  42 . The indication marks  78  may therefore correspond to the current depth of the barrier member  12  being inserted when a detectable body is expected to be detected by the detector  70 . In such embodiments it will be appreciated that the detectable bodies  40  would be beneficially arranged at regular intervals. 
     Turning now to  FIG. 7 , a cross-sectional view of an alternative embodiment of a barrier member is shown generally at  80 . As illustrated, the barrier member  80  may have first and second side edges,  82  and  84 , respectively having corresponding first and second connectors  86  and  88 , respectively. The first and second connectors  86  and  88  are adapted to interconnect with first and second connectors of adjacent barrier members to form a continuous barrier wall. As illustrated the first connector  86  may comprise a flange  87  as described above with reference to  FIGS. 2 through 6 . The second connector  88  may comprise a c-shaped channel  89  similar to the c-shaped channel shown in  FIGS. 2 through 6 . As illustrated, the c-shaped channel  89  may be eccentrically connected to the barrier member  80 . In the present embodiment, the detectable bodies may be located to one side of the flange  87  of the first connector  86  while the detector  70  is located to the corresponding side of the c-shaped channel  89  of the second connector  88 . The barrier member may also include a longitudinal seal  60  within the c-shaped channel  89 . It will be appreciated that for embodiments having a longitudinal seal  60 , that the detectable bodies may be located in an end surface  85  of the flange  87 . 
     Turning now to  FIG. 8 , a cross-sectional view of a further alternative embodiment of the barrier member is shown generally at  90 . As illustrated, the barrier member  90  may have first and second side edges,  92  and  94 , respectively having corresponding first and second connectors  96  and  98 , respectively. The first and second connectors  96  and  98  may have substantially similar profiles. As illustrated the first and second connectors  96  and  98  may be mirror images of each other. With reference to the second connector  98 , each connector may comprise a c-shaped channel  99  formed by first and second portions,  100  and  102  respectively. As illustrated, the second portion  102  may have a flange  104  at a distal end thereof. The flange  104  is adapted to be received within the c-shaped channel  99  of an adjacent barrier member  106 . It will be appreciated that the adjacent barrier member  106  may be inverted about a horizontal axis such that the flange  104  of each barrier member is received within the c-shaped channel  99  of the other barrier member. In the present embodiment, the detectable bodies may be located in the flange  104  while the detector  70  is located to at a portion of the c-shaped channel  99  adapted to correspond to the detectable bodies  40 . Alternatively, each barrier member may include a detector  70  and detectable bodies  40  such that each barrier member  90  detects the detectable bodies of the adjacent barrier member. Accordingly, such a system may have a redundant system for checking continuity of the barrier wall. The barrier member may optionally have longitudinal seals or have the detector  70  and detectable bodies located to one side of the flanges  104  and c-shaped channels  99  as discussed above. 
     Turning now to  FIG. 9 , a cross-sectional view of an alternative embodiment of the barrier member is shown generally at  110 . As illustrated, the barrier member  110  may have first and second side edges,  112  and  114 , respectively having corresponding first and second connectors  116  and  118 , respectively. The first and second connectors  116  and  118  are adapted to interconnect with first and second connectors of adjacent barrier members to form a continuous barrier wall. As illustrated, the first connector  116  may comprise large c-shaped channel  120  continuously formed with the barrier member  110 . The second connector  118  may comprise a small c-shaped channel  122  continuously formed with the barrier member  110 . As illustrated the small c-shaped channel  122  may connected at an opposite side to the side of the large c-shaped channel  120  that is connected to the barrier member  110 . The small c-shaped channel  122  is adapted to be interlockably received within the large c-shaped channel  120  as illustrated. In the present embodiment, the detectable bodies may be located at any location around the c-shaped channel  120 , to be detectable by detectors at one or more of a plurality of locations such as by way of non-limiting example, a distal detector  42   b  proximate to a distal end  124  of the c-shaped channel or as an internal detector  42   b  at a transition  126  of the c-shaped channel to the barrier member  110 . The barrier member may optionally have longitudinal seals as discussed above located within the interconnection therebetween. 
     Turning now to  FIG. 10 , a cross-sectional view of an alternative embodiment of the barrier member is shown generally at  130 . As illustrated, the barrier member  130  may have first and second side edges,  132  and  134 , respectively having corresponding first and second connectors  136  and  138 , respectively. The first and second connectors  136  and  138  are adapted to interconnect with first and second connectors of adjacent barrier members to form a continuous barrier wall. 
     As illustrated, the first connector  138  may comprise u-shaped channel  140  formed between a first upright  142  and a second upright  144 . The second upright  144  forms a first engagement surface  146  oriented at an angle generally indicated at  148  from perpendicular to the barrier member  130 . The second connector  136  comprises an inverted u-shaped channel  150  having a proximate end  152  continuous with the barrier member  130  and a free distal end  154 . The inverted u-shaped channel  150  includes a second engagement surface  156  having an angle corresponding to the angle  148  of the first engagement surface. The free distal end  154  of the first connector  136  is adapted to be received within the u-shaped channel  140  such that the first engagement surface  146  bears against the second engagement surface  156 . In the present embodiment, the detectable bodies  40  and detectors  70  may be located at any locations within the inverted u-shaped channels  150  and the u-shaped channel  140  such that they will be proximate to each other when adjacent panels are interconnected. The barrier member may optionally have longitudinal seals as discussed above located within the interconnection therebetween. 
     While specific embodiments of the invention have been described and illustrated, such embodiments should be considered illustrative of the invention only and not as limiting the invention as construed in accordance with the accompanying claims.