TECHNICAL FIELD
The present invention relates generally to the field of barrier walls; and more particularly to slurry walls incorporating sheet pilings, and to systems, apparatus and methods for construction of slurry walls incorporating one or more sheet piling panels.
BACKGROUND
Slurry or soil mix walls are commonly used to provide in-ground barriers or structural walls, for example to prevent migration of groundwater or other fluids, and/or for various structural applications. For example, slurry walls may be utilized in various applications, including landfills, mining, tunnels, earth stabilization, foundation construction, barrier walls, retaining walls, seawalls and the like.
Typically a trench is excavated in the earth and filled with a cementitious and/or bentonite based slurry which hardens or cures to form a barrier. The trench may be formed using an excavator or trench cutter, for example a vertical cutter post (resembling a large vertical chain saw), which may be mounted to a base crawler machine to advance the excavator along the path of the wall to be formed. The cementitious slurry may be continuously injected as the trench is excavated, to refill the trench and prevent caving or collapse of the earth along the trench being formed. A trench remixing deep (TRD) process may be utilized to continuously vertically mix a cement-based binder slurry with in-situ soil or rock to eliminate soil stratification along the wall's depth, and form a homogenous and low permeability barrier wall.
While generally effective for many applications, typical known slurry wall constructions have been found to have shortcomings in some other applications. For example, in seismically active areas, or areas incurring vibration or shock from blasting, tunneling, mining or other activities, slurry walls may be prone to cracking, thus degrading their effectiveness as a barrier against groundwater or other fluid migration, and potentially rendering them structurally unstable. Significant shifting in surrounding earth, for example from hydrostatic pressure, thermal expansion and contraction, tree roots, geological activity, and/or other causes may also damage or degrade barrier and/or structural integrity of traditional slurry wall constructions. Accordingly, it can be seen that needs exist for improved slurry walls providing better or more durable barrier and/or structural characteristics.
Additionally, it has been found that known methods of slurry wall construction are generally incompatible with the incorporation of barrier panel elements such as sheet piling members into a traditional slurry wall construction. For example, if construction of a slurry wall is interrupted, for example at the end of a workday or due to equipment problems, hardening and curing of the cementitious slurry around a leading edge lock engagement feature of a previously installed sheet piling member will interfere with proper engagement of the trailing edge lock engagement feature of a subsequently installed sheet piling member, rendering it difficult or impossible to properly form a continuously interlocked array of sheet piling members within a slurry wall using traditional slurry wall construction techniques. Accordingly, it can be seen that needs exist for improved systems, apparatus and methods for construction of slurry walls.
It is to the provision of improved slurry wall constructions, and to improved systems, apparatus and methods for construction of slurry walls meeting these and other needs that the present invention is primarily directed.
SUMMARY
In example embodiments, the present invention provides improved slurry wall constructions having better and/or more durable barrier and/or structural characteristics, and improved systems, apparatus and methods for construction of slurry walls.
In one aspect, the invention relates to a wall construction or wall system preferably including a sheet piling barrier in combination with a slurry wall. In example forms, the sheet piling barrier includes one or more sheet piling panels having a top side, a bottom side, a leading edge and a trailing edge, and the leading and trailing edges include interlocking engagement profiles for joining a plurality of such sheet piling panels into a continuous array. The slurry wall preferably includes a cementitious or bentonite material that cures or hardens around or alongside the sheet piling barrier. The sheet piling barrier is at least partially submerged or embedded in the slurry wall, optionally entirely embedded, or alternatively partially embedded and partially extending above the slurry wall or ground surface. A wall system combining a sheet piling secondary barrier within a slurry wall primary barrier may provide improved barrier and/or structural characteristics in many applications, relative to standard slurry wall constructions.
In another aspect, the invention relates to a method of constructing a slurry wall system having a sheet piling barrier at least partially embedded within a slurry wall. The method preferably includes excavating a trench, depositing or mixing a cementitious or other slurry material within the trench, and installing at least one sheet piling member into the trench at least partially submerged or embedded in the slurry material. The at least one sheet piling member preferably includes a leading edge and a trailing edge with cooperatively engaging interlock profiles, whereby multiple sheet piling members can be sequentially installed, with their respective interlocks engaged to form a substantially continuous sheet piling barrier array. The slurry wall material is then allowed to harden or cure around or alongside the installed sheet piling members.
Optionally the method further includes placement of a void creation device on the leading of a first sheet piling member installed in the cementitious slurry, and displacing the cementitious slurry from within at least a portion of the void creation device. The method may further include depositing a non-cementitious non-hardening fill or slurry material into at least a portion of the void creation device around leading edge of the first sheet piling member and optionally removing the void creation device. The method may further include installing a second sheet piling member into engagement with the first sheet piling member. The method may further include removal of at least a portion of the non-cementitious non-hardening fill or slurry material from adjacent the leading edge of the first sheet piling member prior to installing the second sheet piling member. In this manner, the installation process can be interrupted, for example at the end of a workday or in the event of equipment breakdown, and prevent curing or hardening of the slurry material around the leading edge of the last-installed sheet piling member, which could otherwise prevent attachment of a subsequent sheet piling member.
In still another aspect, the invention relates to a void creation device for installation of sheet piling members into a slurry wall. The void creation device preferably includes an elongate body enclosing an internal channel surrounded by at least one wall creating a top edge and a bottom edge. The at least one wall preferably includes a slot with an opening at the bottom edge of the elongate body wherein the slot extends at least a portion of the length of the elongate body, and wherein the slot is configured to receive a leading edge of a sheet piling.
Optionally, the void creation device further includes at least one fluid delivery conduit for diluting or displacing a cementitious slurry from the internal channel and/or for delivery of a non-cementitious slurry into the internal channel.
In another aspect, the invention relates to a subterranean barrier wall system. The barrier wall system preferably includes a cementitious slurry wall primary barrier and a sheet piling secondary barrier at least partially in contact with the cementitious slurry wall primary barrier. The sheet piling secondary barrier preferably includes a plurality of sheet piling elements, each sheet piling element having a male interlock and a female interlock, wherein the male interlock of a first sheet piling element is received in the female interlock of a second sheet piling element.
These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description are exemplary and explanatory of representative embodiments of the invention, and are not restrictive of the invention, as claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a wall system incorporating sheet pilings at least partially within a slurry wall according to an example embodiment of the present invention.
FIG. 2 shows a method of construction for creating the slurry wall system incorporating sheet pilings shown in FIG. 1, with a trencher advancing through the ground, a slurry wall being formed trailing the trencher, and an array of sheet piling members at least partially embedded in the slurry wall.
FIG. 3 shows a perspective view of a void creation device according an example embodiment of the present invention.
FIG. 4 is a side view of the void creation device depicted in FIG. 3.
FIG. 5 shows a bottom view of a void creation device depicted according to another example embodiment of the present invention.
FIG. 6 is a perspective view of the void creation device depicted in FIG. 5.
FIG. 7 is a side view of the void creation device depicted in FIG. 5.
FIG. 8 is an alternate side view of the void creation device depicted in FIG. 5.
FIG. 9 is a detailed view of the bottom end of the void creation device of FIG. 7.
FIG. 9A is a detailed view of the leading edge receiver slot of the void creation device of FIG. 9.
FIG. 10 shows a perspective view of the top of a void creation device showing connection couplings for the fluid delivery conduits according to an example embodiment of the present invention.
FIG. 11 is an alternate perspective view of the top of the void creation device of FIG. 10.
FIG. 12 shows an in-situ view of a void creation device inserted onto a leading edge of a sheet piling, according to example form of the present invention.
FIG. 13 shows the void creation device of FIG. 12 partially inserted into the trench.
FIG. 14 shows the void creation device of FIG. 12 partially retracted from the trench.
FIG. 15 shows the void creation device of FIG. 12 fully retracted from the trench and sheet piling after use.
FIG. 16A-E shows the sequence of an example method of construction of a slurry wall system incorporating sheet pilings using a void creation device according to an example form of the invention.
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
The present invention may be understood more readily by reference to the following detailed description taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein.
Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views, FIGS. 1-16 show improved systems, apparatus and methods for construction of slurry walls incorporating sheet pilings. FIG. 1 shows a wall construction or wall system incorporating sheet pilings 100 in combination with a slurry wall 120, according to an example embodiment of the present invention. As depicted, a plurality of sheet piling panels or members 110 are at least partially embedded within at least a portion of slurry or cementitious-soil mix 120 to form the slurry wall system 100. The sheet pilings 110 generally comprise a top end 112, a bottom end 114, a leading side edge 116 and a trailing side edge 118. In example embodiments, the sheet pilings 110 include cooperating lock engagement features on the leading edges 116 and trailing edges 118. For example, the leading edge 116 of the sheet piling 110 can include a male lock engagement feature and the trailing edge 118 of the sheet piling 110 can include a female lock engagement feature, allowing multiple sheet pilings to be linked side to side in an array. Various forms of sheet piling wall construction panels are known, which may be adapted for use in connection with the slurry wall system 100 of the present invention. Examples of sheet piling walls are shown in U.S. Pat. No. 6,000,883, U.S. Pat. No. 7,025,539, U.S. Pat. No. 6,053,666, U.S. Pat. No. 6,033,155, U.S. Pat. No. 8,419,317, U.S. Pat. No. 5,503,503, U.S. Pat. No. 5,803,672, U.S. Pat. No. 6,231,271, and U.S. Pat. No. 7,914,237, all of which are incorporated herein by reference. In example embodiments, the sheet pilings 110 are formed of vinyl, PVC, fiber reinforced polymer, plastic, polymer, composite or other polymeric or non-metallic material(s). In alternate embodiments, the sheet pilings can comprise steel, aluminum or other metals, ceramics, or other materials. The sheet pilings can comprise a C-shaped, S-shaped, flat, angled, curved, or other cross-sectional profile.
The combination of slurry wall 120 and sheet pilings 110 in a wall system can provide improved fluid barrier capability and/or improved structural integrity in many applications, relative to a traditional slurry wall construction. To construct the slurry wall system 100 shown in FIG. 1, a subterranean trench 130 is excavated below ground surface, as shown in FIG. 2. In example embodiments, a trenching device 132, or trencher is used. The trencher 132 can be an excavator or trench cutter, for example a vertical cutter post or hydromill trench cutter, which may be mounted to a base crawler machine to advance the excavator along the desired path of the slurry wall system 100. The trench 130 is partially or fully filled with the uncured slurry mix 120 below the ground surface, which is typically a free-flowing wet cementitious material such as concrete or a cementitious-soil or bentonite mix. In some embodiments, the cementitious slurry 120 is continuously injected as the trench 130 is excavated, to refill the trench and prevent caving or collapse of the earth along the trench being formed. In further examples, a trench remixing deep (TRD) process can be utilized to continuously vertically mix a cement-based binder slurry with in-situ soil or rock to eliminate soil stratification along the wall's depth and form a homogenous and low permeability barrier wall. Before the slurry mix 120 hardens, the sheet pilings 110 are inserted into the trench and at least partially extending below the ground surface, preferably in a connected array, with the female interlock of one sheet piling member engaging the male interlock of the adjacent sheet piling member. The sheet pilings 110 are arranged so that they are at least partially submerged in the slurry mix 120. The slurry mix 120 cures and hardens around or along the sheet pilings 110 to form a combination wall system 100 incorporating a sheet piling secondary barrier within a slurry wall primary barrier. In alternative embodiments, the slurry mix 120 can be added to the trench 130 after the sheet pilings 110 are installed. For example, a non-cementitious bentonite slurry material can be deposited in the trench to prevent wall collapse, the sheet pilings installed therein, and concrete or other cementitious slurry material deposited to replace the bentonite slurry in the trench on one or both sides of the sheet pilings.
If construction of the slurry wall system is halted before the wall construction is complete, for example at the end of the work day or due to equipment problems, the cementitious slurry mix could harden around the leading edge of the last installed sheet piling. The hardened slurry mix would make it difficult or impossible to connect the trailing end interlock of the next-installed sheet piling to the leading end interlock of the last-installed sheet piling when work resumes. In this situation, a void creation device 250, as depicted in FIGS. 3 and 4, can be used. The void creation device 250 generally comprises an elongate hollow body or beam 252 defining an internal void or channel 254 and a lock channel or slot 256. The internal channel 254 is surrounded by at least one wall forming a top end or edge 240 and a bottom end or edge 242. The body 252 can be constructed of metal, such as steel, or another rugged material. In the depicted embodiment, the elongated body 252 has a generally square cross-section. In other embodiments, a round cross-section pipe or other member having different cross-sectional shapes can be used. Preferably, the body 252 is sufficient length so it is at least as tall as the sheet pilings.
The void creation device 250 includes a lock channel or slot 256 in a wall of the elongated body 252. In the depicted embodiment, the lock channel 256 is formed as a slot in one wall of the elongated body 252 extending thru to the internal void 254. The lock channel 256 begins at the bottom edge 242 of the body 252 and extends at least partially up the length of the body. In the depicted embodiment, the lock channel 256 extends to the top edge 240 of the elongate body 252. The lock channel 256 is configured to receive a portion of the leading edge of the last installed sheet piling, for example including the male (or female) interlock, so that the leading edge of the last installed sheet piling is positioned within the internal void 254. The top of the body 252 can include support beams 260 attached to the top edge of the elongate body. The void creation device 250 can further include a bite plate 262 attached to the top edge of the body 252. In the depicted embodiment, the bite plate 262 is attached above the cross beams 260, such that the length of the bite plate is perpendicular to the length of the cross beams. The depicted bite plate 262 further includes triangular braces 264 at each end of the bite plate. The bite plate 262 is designed to engage with a device such as a crane to assist with insertion of the void creation device 250 into the trench and/or slurry mix. The depicted void creation device 250 also includes lifting holes 266, for example in the bite plate 262 and triangular braces 264. The lifting holes are designed to engage with a device such as a crane for removing the void creation device 250 from the trench.
FIGS. 5-8 show a void creation device 350 according to another example embodiment of the claimed invention. The depicted embodiment includes pipes, tubing, hoses or other fluid delivery conduits 370 mounted to the inside wall of the body 352 within the internal channel 354 of the void creation device 350. As shown in FIGS. 5-6, the fluid delivery conduits can include two slot tubes 372, located on either side of the of the lock channel 356, and two side tubes 374 located on the two walls of the body 352 perpendicular to the wall containing the lock channel 356. In alternate embodiments, different numbers and configurations of fluid delivery conduits can be used. In the depicted embodiments, the fluid delivery conduits 370 are mounted to the inside the walls of the body 352 with series of brackets 376 that extend around the fluid delivery conduit 370 and attach at each end to an inside wall of the body 352. As shown in FIGS. 7 and 8, the fluid delivery conduits 370 extend from the top of the body 352 at least partially down the length of the body. The fluid delivery conduits 370 can be positioned to discharge fluid at different depths inside the channel 354 of the void creation device 350. For example, in the depicted embodiment, the two slot tubes 372 extend the full depth of the body 352 whereas the side tubes 374 include one conduit extending about one half the depth of the body and another extending about three quarters the depth of the body. Varying the depths of the fluid delivery conduits 370 helps to dilute and displace the slurry mix along the length of the void creation device 350.
FIGS. 9 and 9A show detailed views of the void creation device 350. As shown in FIG. 9, the discharge ports 378 of the fluid delivery ports 370 are angled. The angled discharge port 378 helps to direct fluid flow when flushing the slurry mixture. In the depicted example, the discharge ports 378 of the slot tubes 372 are angled to help flush slurry from around the opening 258 of the lock channel 256. As shown in the detailed view of FIG. 9A, the lock channel opening 258 can optionally include a radiused or tapered lead-in or leading edge. The tapered edge enlarges the opening to assist in guiding the receiver slot 356 of the void creation device 350 onto the leading edge of the sheet piling.
FIGS. 10 and 11 show a void creation device 450 according to another example embodiment of the present invention. The void creation device 450 of this embodiment is substantially similar to that of the previous embodiment. In the depicted embodiment, the fluid delivery conduits 470 include fittings for connecting to a supply line 480. The supply line 480 delivers fluid and/or filing material to the fluid delivery conduits 470. Optionally, one or more Y or T couplings 482 are employed to deliver fluid from a common supply line 480 to two or more fluid delivery conduits 470. In alternate embodiments, a controlled valve operation and/or appropriate sizing of the fluid delivery conduits may be provided to vary fluid delivery pressure and/or flow-rate to the fluid delivery conduits discharging at different depths along the void creation device.
FIGS. 12-15 show a sequence of operation of a wall system construction method according to an example embodiment of the invention. As shown in FIG. 12, the void creation device 450 is inserted into the uncured cementitious slurry wall material 420, with the leading edge lock profile 416 of the last installed sheet piling member 410′ extending through the lock channel or receiver slot 456 and positioned within the internal void or channel 454 of the void creation device. The void creation device is driven into the slurry wall mixture 420 at least a portion of the depth of the sheet piling 410. In preferred embodiments, the void creation device 450 is driven into the slurry wall mixture 420 a depth at least equal to the depth of the sheet piling 410. Water or other fluid is pumped through the fluid delivery conduits into the internal void or channel of the void creation device 450 through one or more supply lines 480. The fluid dilutes and/or flushes the concrete or cementitious slurry wall forming material 420 from around the leading edge lock profile 416 of the last installed sheet piling 410′. A non-cementitious fill material 422, such as clay or bentonite clay slurry is optionally deposited into the internal void of the void creation device to replace the concrete or cementitious slurry. The non-cementitious fill material 422 can be inserted through the fluid delivery conduits, by a separate pumped delivery system, or by other means. As shown in FIGS. 14 and 15, the void creation device 450 is retracted and removed leaving the non-cementitious fill material encapsulating the leading edge lock profile 416 of the last installed sheet piling 410′. Work can then be temporarily stopped, for example overnight or over a weekend. Then when work resumes, the non-cementitious fill material is removed from around the leading edge lock profile 416 of the last installed sheet piling 410′, and one or more additional sheet piling members can be sequentially installed as the slurry wall construction is continued in like manner as described.
FIGS. 16A-E show steps of a multi-stage installation method for constructing a combination sheet piling and slurry wall system 500, using a void creation device 550. As previously described, a trenching device 532 is advanced along the desired path of the slurry wall system 500, as shown in FIG. 16A. The trench 530 is filled with a cementitious slurry mix 520 and sheet pilings 510 are inserted into the trench when the slurry mix is wet and uncured such that the sheet pilings are at least partially submerged or embedded in the slurry mix. The cementitious slurry mix 520 is allowed to harden and cure around or along the previously installed sheet pilings 510 as the wall construction proceeds in a continuous fashion.
If the slurry wall formation process is interrupted, for example at the end of a work day, a void creation device 550 is employed, as shown in FIG. 16B. The void creation device 550 is installed to depth over the leading edge 516 of the last sheet piling installed 510′. In the depicted embodiment, the void creation device 550 is fitted over the leading male lock profile 516 of the last installed sheet piling 510′. Water or other fluid is pumped into the void creation device 550 to dilute and flush the cementitious slurry 520 from around the sheet piling lock profile 516. The diluted slurry mixture is sufficiently non-cementitious and will not harden around at least the leading edge interlock profile of the last installed sheet piling. Optionally, a non-cementitious material 522 is added to the void creation device 550. In alternate embodiments, the void creation device can be installed over the leading edge of the last installed sheet piling before the trench is filled with the cementitious mixture to prevent the cementitious slurry wall material from embedding the leading edge. As shown in FIG. 16C, the void creation device 550 is removed, leaving the leading edge 516 of the last installed sheet piling 510′ surrounded by non-cementitious material 522. When the slurry wall formation process is resumed, the trencher 532 can be backed toward the leading edge 516 of the sheet piling 510′ to remove the non-cementitious fill material for access to install the next sheet piling 510, as shown in FIG. 16D. The trencher 532 is advanced to continue formation of the slurry wall system 500, as shown in FIG. 16E, and additional sheet piling members can be sequentially installed as the slurry wall construction proceeds, in like manner as described above.
While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.
Patent Application
20170030041
