Patent Application
20180216307
The invention belongs to the technical field of static press-fit (press-in) underground space development. The invention may be used for adjusting the distance in the axial spacing of greater than one, but smaller than two, wall-forming devices when a terminal wall of the continuous underground diaphragm wall is about to be closed (encircled). More specifically, the invention relates to a variable-pitch wall-forming device and methods of use thereof.
At present, the normal docking between the wall segments of a press-fit underground continuous wall (hereinafter referred to as a press-fit underground wall) at home and abroad is based on hingedly connecting mechanical connectors one by one in the axial order. However, when the construction is about to complete by encircling the wall, the spacing between the two wall-forming devices, the first and the last, will not leave exactly a standard connection distance for a wall-forming device. From the perspective of accuracy control, it is unrealistic to expect no errors in hundreds or thousands of connections in underground wall construction. Furthermore, the building boundary line will not be premised on the fixed sizes of the wall-forming devices.
The existing techniques for the last-step encirclement of press-in (press-fit) underground walls require human intervention to remedy the remaining gaps. In practice, it has been found that the press-in walls that were enclosed with human help not only have poor water sealing effects, but the joints are also very weak. Such walls have difficulty in performing waterproofing, soil retention, and weight bearing duties. Therefore, overcoming the problem of variable distances in the axial direction at the final connection for two wall-forming devices, the beginning and end sections, is a key technique to ensure that the press-in underground wall will retain its soil-retention, water-blocking, permeability resistance, and load-bearing functions.
An object of the invention is to provide devices and methods that can connect a press-in wall ends that have a variable axial distance greater than a single wall-forming device, but smaller than two wall-forming devices. That is, the invention relates to a wall-forming device for press-in underground continuous wall and methods of use.
To achieve the above object, a device of the invention includes a fixed-pitch box, a variable-pitch box, a wall shoe (or wall boot), and a vibration chamber. The variable-pitch box is installed in the fixed-pitch box. The wall shoe is arranged at the bottoms of the variable-pitch box and fixed-pitch box. The vibration chamber is arranged on the side walls of the fixed-pitch box and the variable-pitch box.
The fixed-pitch box comprises a main body, a point connector, and an outer box body. The main body is an open rectangular box having a side-way “U” shaped cross section, which has a long side length of 400-1200 mm, a short side inner length of 200-1000 mm, and a short side outer length of 300-1100 mm. Along the short side wall of the main body, point connectors are arranged vertically (in a column) at a select spacing, and the point connectors are bolted or welded on the side wall. A point connector comprises two rectangular body having the same shape and size, forming a dovetail-shaped trough (groove) at the center of the short sides of the main body. To minimize friction, the point connectors may be disposed along the vertical direction with a large spacing and the vertical length (thickness) may be short. Dovetail trough (groove) is used to be sleeved (coupled) with a dovetail convex track of an adjacent wall-forming device. Once coupled, the wall-forming device and the variable-pitch wall-forming device can only slide vertically relative to each other and cannot separate or move in the radial direction. Point connectors near the junction of the upper and lower sections can be longer to improve the strength. One side of the joint has a seal groove, to facilitate installation of seals to prevent leakage. On the inner walls of the main body, there are two horizontal troughs with an arc-shaped cross section. The first section of the device that enters the soil first is referred to as a main guide section, with a length of ≤50 meters. The bottom of the main guide section is open and is closed with a wall shoe. The section that connects vertically with the main guide section is an extension section. The upper and lower sections connects via junction, which can be secured with bolts. In addition, the upper and lower section joint region also has structures for vertical bolt connections. The shape and structure of the extended section are the same as the leading section. Depending on the engineering requirements for the strength and waterproofing of the supporting structures, these sections can be made to have different lengths and different thickness to meet a variety of specifications. The outer box body is a rectangular box body with a certain thickness and the same length as the main body, and is provided with a section at intervals (spacing) along the vertical direction of the main body, fixed with sunken head bolts on the outer wall of the long side of the main body, spacing is not directly related, but with the wall pressure cylinder stroke to be consistent. Within the cross section area of the outer box, there are sufficient holes for running cables, ducts and waterways in the vertical direction. The upper and lower outer box with the corresponding edge of the shoulder, for the installation of vibrating plates.
The variable-pitch box includes a drawer box, an assembled outer box body, and a dovetail track.
The shapes of the fixed-pitch box and the variable-pitch box are the same. The outer dimension of the long side and the inner short side of the drawer box and the inner side of the long side and the short side of the main body only fit with tolerances. The drawer boxes correspond to the horizontal arc slots of two long sides of the main body. There are mutually consistent long horizontal arc convex track, the drawer box from the short side of the main body open along the horizontal arc slot into the body cavity, and along the main body can move horizontally to the short side of the short side wall, But the vertical was two long sides of the main body up and down a total of two horizontal curved slot to limit the displacement of the bottom of the drawer height=the bottom of the main body−the height of the slope of the wall boots to prevent the drawer bottom wall and the top of the ramp against the wall. When the tank into the underground tank wall closed at the bottom end of the opening. The drawer box is located in the short side of the main body cavity and is called the short side. The short side outside the main body is called the outer short side. The wings on both sides of the outer short side are formed with winged wings. Short side length+outer box body thickness; along the center of the short side of the drawer vertical center vertical or intermittent with dovetail convex track, dovetail track for docking with adjacent wall dovetail device nesting hinged. When squeezed into the ground wall, the remaining space between the two wall-forming devices will eventually change between more than 1 and less than 2 from the axial distance of the wall forming device. Therefore, the outer box body of the drawer box should not be fixed sized, and should be composed of multiple pieces of assembly, called the assembled outer box. Assembled outer box body through the countersunk head bolt fixed to the outer wall of the two long sides of the drawer, the vertical length of the outer body with the main body, the thickness of the outer body of the main body Thickness+length of the main body long side; when used according to the actual distance between the two walls before and after the device to choose different width assembled outer box body composition greater than 1 less than 2 range of any width, combined with drawer with axial displacement fine tuning characteristics Can be successfully completed into the wall device in crowded into the wall at the end of the surrounding area greater than 1, but smaller than 2, mechanical connections between the wheelbase.
The wall shoe is a triangular prefabricated reinforced concrete component as seen from the front elevation, with the upper end of the wall being a certain slope; the intersection of the slope and the lower plane is provided with a step protruding to the periphery horizontally; and the groove on the step plane is provided with a waterproof pad. When the upper end of the wall boots is set into the body and the lower end cavity of the drawer box is squeezed into the ground, the protruding steps of the wall boots bear the full squeezing force transmitted by the distance box+the lower end face of the distance box, Force against the waterproof pad through the closure of the end of the tank+the end of the tank, mud or impurities can not enter from the step into the distance box+tank compartment; when the distance+Resistance and the distance between the tank and the tank+change the gravity mixture on the top of the wall, so that it can not be accompanied by the rise, was permanently left in the ground, wall boots cross-section size can be selected according to the distance box+Size setting.
The vibration chamber comprises a vibration frame, a vibration plate, a vibrator, a water outlet valve, a cable, an air duct, and a water pipe. In the distance between the long distance box+variable length box two vertical outer box (including assembled outer box, the same below), the preparation of a vibration plate, the upper and lower ends with countersunk head bolts in the corresponding outer box on the shoulder, horizontally to the wings with countersunk head bolts bolted to the body+drawer box border, so that a closed cavity volume called the vibration chamber; the main frame is welded to the outer edge of the main body long vertical. The edges of both sides of the drawer box vibrating room are movable borders, which are respectively fixed on the main body frame and the drawer wings by bolts when in use. The plane size of the drawer box frame is larger than that of the main frame and the vibration plate is arranged horizontally in the plane of the drawer box fine-tuning. Electric vibrator with “Ω” card, air vibrator with flange are mounted with bolts on the inner wall of the vibration plate. Cables, duct and pipe connections are disposed in the vibration chamber. A set of vertical water pipes, cable ducts or air ducts are arranged along the cross-sectional area of the outer box and the outer box of the tipping box. The water pipes are set according to the required quantity of the electric vibrators and the water outlet valves. If the use of air vibrator then change the cable duct for the wind. The lower part of the leading segment of the vibration chamber and the extension of the uppermost vibration chamber are provided with vertical water pipe in series with the horizontal circulation pipe, cooling water into the water inlet manifold by the pump into the upper and lower into the lower horizontal circulation pipe and into the adjacent A vertical water pipe, and then from the first vertical water pipe into the upper horizontal circulation pipe into the second vertical pipe down to the next horizontal circulation pipe, thus entering the third vertical pipe upstream. So the cycle eventually To the water mains discharged to the cooling water tank, after cooling water tank and then into the water by the pump repeats cycle. The inner wall of the vibrating plate is provided with a water outlet valve which is communicated with the corresponding water outlet on the vibrating plate, In the exciting force, amplitude and infiltration superposition, the main squeeze out and pull out easily solved. Cables and pipes are “Ω”-shaped (horseshoe shaped) card/plate were fixed in the vibrating chamber main body+drawer box on the long side of the outer wall. The electric vibrator quantity is set according to the electric vibrator or other requirements. The electric vibrator is a high-temperature component when it works, and requires a large amount of cooling water. The air source vibrator neither needs water cooling nor direct power supply, and is a safer and preferred vibration device. Vibrator function is to produce a certain exciting force and amplitude, to reduce the body of the squeeze-in and pull-out friction as well as the concrete vibration to provide aids.
Uses of a device of the invention include three technical aspects: adjusting variable-pitch principles and applications, prefabrication of wall shoes, and mechanical connection to encircle the wall.
(1) variable pitch adjustment principles and applications: based on the actual distance between two front and rear wall-forming devices, the drawer box 22 is moved to the proper position on the ground to start the assembly. If the actual distance between the two wall-forming devices already pressed-into underground is within the fine adjustment range of the drawer box 22, then one only needs to move the drawer box 22 axially for a corresponding distance and there is no need to added the assembled outer box body 7′. Therefore, the drawer box 22 and the vibration plate 21 have their own fine-tuning characteristics for any pitch. Understanding this feature, one can assemble a variable-pitch wall-forming device with many variable pitch parameters, using a combination of the fixed-size assembled outer box 7′ and the vibrating plate 21+drawer box 22.
(2) Wall shoe 3 prefabrication: the wall shoe 3 is produced based on the final axial dimension at the bottom of the wall-forming device. This information was not available before-hand. However, in actual use, continuous pre-fabrication work is required to be carried out in advance. Based on experience, the axial size of the wall shoe 3 is estimated. When prefabricating step 26, the cross-sectional area should rather be larger than smaller. A larger cross section does not affect the use, and the increase in the area of the press-in end is insignificant. The cross section of the slope 25 should be small. A large cross-section of slope 25 may make it difficult to fit in the main body 5+drawer 22 cavity. A small cross-section of slope 25 can be filled in with hard and dry concrete or other fill material and it would be ready to use.
(3) Mechanical connection closure: When the drawer box 22 of the variable-pitch wall-forming device moves axially, the short side 23 of the drawer box 22 moves along with it. The inner short side 23 plays an important role in resisting the strong bracing stress of the multi-functional wall-clamping device and prevents deformation of the long side 15 of the main body. Because the location of the short side 23 of the drawer box 22 in the inner cavity of the main body 5 is not fixed, based on the cavity size divided by the main body 5 and the short side 23 of the drawer box, two reinforcing steel cages are respectively arranged in the cavities of the main body 5 and the drawer box 22 to enhance the rigidity of underground continuous wall. The variable-pitch wall forming device provides mechanical connection of the press-fit wall during the final closure. It connects the first closed press-fit wall-forming device at one end and the last press-fit wall-forming device at the other end. One needs to control the process sequence: Step 1, along the same axis, the dovetail track 11 of the variable-pitch wall-forming device should align with the dovetail trough 10 on the closed wall-forming device, while the dovetail trough 10 of the variable-pitch wall-forming device should align with the dovetail track 11 of the adjacent last wall-forming device. Step 2: couple the variable-pitch wall-forming device with the two connects on the two previously press-in underground wall-forming devices, and gradually press into the ground to a predetermined depth, thereby completing the final mechanical connections for encircling the press-fit wall. Step 3: first, pour concrete into the first closed wall-forming device and gradually pull out the device. Step 4: pour concrete into the last wall-forming device and gradually pull out the device. Step 5: pour concrete into the variable-pitch wall-forming device and gradually pull out the device. The press-fit underground wall is eventually completed without gaps.
The present invention solve a technical problem that connects press-fit underground wall having variable axial distance at the last stage of closure, ensuring that the press-fit wall can function to retain soil, block water, resist permeability, and bear weights.
In the Figures, 1 fixed-pitch box; 2 variable-pitch box; 3 wall shoe; 4 vibration chamber; 5 main body; 6 point connector; 7,7′ outer box body; 8 short side; 9 bolts; 9′ flat head (sunken) bolts; 10 dovetail trough (groove); 11 dovetail (protruded) track; 12 junction; 13 seal trough; sealing ring; 15,15′ long side; 16 horizontal trough with arc-shaped cross section; 17 horizontal protruded track with an arc-shaped cross section; 18 main guide section; 18′ extension section; 19 hole; 20 shoulder; 21 vibration room (cavity); 22 drawer box; 23 inner short side; 24 outer short side; 24′ wing; 25 slope; 26 steps; 27 trough (groove); 28 main body frame; 28′ drawer box frame; 29 vibrator; 30 water outlet valve; 31 electrical cable; 32 airduct; 33 water pipe; 34 water inlet main pipe; 34′ water outlet main pipe; 35 horizontal circulation pipe; 36 water outlet opening; 37 water outlet path; 28 spring; 39 “Ω” card/plate (horseshoe-shaped plate); 10-1 “t” shaped trough; 10-2 round trough; 10-3 diamond trough; 10-4 sloped side trough; 10-5 oval (elliptical) trough; 11-1 “T” shaped track; 11-2 round track; 11-3 diamond track; 11-4 sloped side track; 11-5 oval track.
Embodiments of the invention will be further described with aid of the following examples and included drawings.
To achieve the above-described objective, a device of the invention comprises a fixed-pitch box 1, a variable-pitch box 2, a wall shoe 3, and a vibrator chamber 4. The variable-pitch box 2 is arranged inside the fixed-pitch box 1. The wall shoe 3 is fixed at the bottom of the variable-pitch box 2 and the fixed-pitch box 1. The vibration chamber 4 is disposed on the side walls of the fixed-pitch box 1 and the variable-pitch box 2.
As shown in
The variable-pitch box 2 includes three components: a drawer box (a sliding box) 22, assembled outer box body 7′, and a dovetail-shaped protrusion track 11.
The variable-pitch box 2 and the fixed-pitch box 1 have the same shape. The lengths of the long side 15′ and short side 23 of the drawer (or “sliding box”) 22 correspond to those of the long side 15 and short side 8 of the main body with a slight difference in length such that they can match. The drawer 22 has an upper and a lower horizontal protrusion tracks 17 with an arc-shaped cross section that match the upper and lower horizontal troughs/grooves 16 with the same arc-shaped cross section. The drawer 22 slides into the inner chamber of the main body 5 from the open end along the arc-shaped troughs 16. The drawer 22 slides horizontally all the way along the long side 15 of the main body until it touches the inner wall of the short side 8 of the main body. The drawer 22 cannot move vertically because it is limited by the horizontal troughs 16 on the long sides 15. The bottom height of the drawer box 22=the bottom height of the main body 5−height of wall shoe slant side 25, such that the bottom of the drawer box 22 will not bump against the top of the wall shoe slant side 25. When pressed-in ground, the variable-pitch box 2 relies on wall shoe 3 to seal off the open bottom end. The short side on the drawer box 22 near the inner chamber of the main body 5 is referred to as the inner short side 23, while the other short side near the open end of the main body 5 is referred to as the outer short side 24. The outer short side 24 is configured like wing shape 24′, and the total length of the outer short side 24, including the wing 24′, equals to the length of the short side 8 of the main body+the thickness of the outer box body 7. Along the center of the outer short side 24, there is provided with a dovetail-shaped protrusion track 11, which can be a continuous piece or in segments. The dovetail-shaped protrusion track 11 is used to engage the dovetail-shaped trough 10 on the neighboring wall-forming device. The distance between the two wall-forming devices at the time of encircling the press-in underground wall is always larger than the axial distance of 1, but less than 2, wall-forming devices. Therefore, the outer box body of the drawer box 22 should not be made in a fixed size, but should be made of an assembly of several pieces, which is referred to as an assembled outer box body 7′. The assembled outer box body 7′ is fixed on the outside of the two long sides 15′ of the drawer box using bolts. The vertical length of the assembled outer box body 7′ is the same as that of the outer box of the main body. Thickness of the assembled outer box body 7′=the thickness of the outer box 7 of the main body+the thickness of the long side 15 of the main body. When in use, depending on the axial distance between the two wall-forming devices, one selects an assembled outer box body 7′ with different widths, to achieve any width within the range, larger than 1 and smaller than 2 wall-forming devices. Furthermore, the drawer box 22 can move in the axial direction to provide fine adjustment. Therefore, one can easily finish the encircling of the press-in underground continuous wall using mechanical sockets within an axial distance of larger than 1, but smaller than 2, wall-forming devices.
The dovetail-shaped trough 10 and the dovetail-shaped track 11 can also adopt other shapes: 10-1 “T” shaped trough, 10-2 round shaped trough, 10-3 diamond shaped trough, 10-4 slant-side shaped trough, 10-5 oval shaped trough, 11-1 “T” shaped protrusion track, 11-2 round protrusion track, 11-3 diamond shaped protrusion track, 11-4 slant-side protrusion track, and 11-5 oval protrusion track. The shapes refer to the cross sections.
The front side perspective view of the wall shoe 3 looks like a precast concrete-steel component, with a slope 25 at the top. The step 26 encircle four sides of where the slope 25 meets the lower horizontal surface. On the step 26, there is a trough 27 for placing a sealing pad. When the top slope 25 is inserted into the lower ends of the main body 5 and the drawer box 22 and pressed into the ground, the step 26 bears the full pressing forces transmitted by the bottoms of the fixed pitch box 1 and the variable-pitch box 2. At the same time, the wall shoe 3 is pushed by the reaction force from the ground, leading to dealing with the sealing pad of the bottoms of the fixed-pitch box 1 and the variable-pitch box 2. Therefore, slurry or contaminants cannot get by the step 26 into the inner chambers of the fixed-pitch box 1 and the variable-pitch box 2. When lifting the fixed-pitch box 1 and the variable-pitch box 2, the wall shoe 3 will be permanently left in the ground because the friction force with the ground, as well as the weight of the mixtures in the fixed-pitch box 1 and the variable-pitch box 2, acting on the wall shoe 3. The size of the wall shoe 3 is based on the dimensions of the selected fixed-pitch box 1 and the variable-pitch box 2.
The vibration chamber includes a main body frame 28, vibration plate 21, vibrator 29, water outlet valve 30, electric cable 31, air duct 32, and water pipe 33. A vibration plate 21 is disposed between the vertical two sections of the outer box bodies of the fixed-pitch box 1 and the variable-pitch box 2 (including assembled type). The upper and lower sections are fixed with bolts 9 at the corresponding outer box shoulder 20. The two horizontal wings are fixed with bolts 9′ on the frame 28 of the main body or on the frame 28′ of the drawer box, thereby forming a closed chamber that is referred to as a vibration chamber 4. The frame 28 of the main body is welded at the two vertical edges of the outside wall of the long side 15 of the main body. The drawer frame 28′ is a moveable frame. It can be fixed on the main body frame 28 and drawer wing 24′ using bolts when in use. The dimensions of the drawer frame 28′ is larger than the main body frame 28. The vibration plate 21 can be disposed such that it can be fine tuned for the horizontal distance. The vibrator, via its “Ω” card, is fixed on the inner wall of the vibration plate 21 using bolts 9, and the air source vibrator is also fixed, via its flange, on the inner wall of the vibration plate 21 using bolts. The connections for electric cables 31, air ducts 32, and water pipe 33 are all in the vibration chamber 4. Within the cross-section area of the outer box body 7 of the fixed-pitch box 1 and variable-pitch box 2, there are water pipe 33, electric cable 31 or air duct 32 running vertically. The number of water pipe 33 is based on the requirements of the electric vibrator 29 and the outlet valve 30. However, the main in-bound water pipe 34 and main out-bound water pipe 34′ only need one each. If the vibrator 29 is an air source vibrator, then the electric cable 31 is replaced with an air duct 32. The water pipes 33 in the vibration chamber 4 at the bottom of the main guide section 18 and the vibration chamber 4 at the top of the extension section 18′ are connected with a horizontal circulation pipe 35. Cooling water is pumped into the main in-bound water pipe and flow down to the lower horizontal circulation pipe 35 and then into the neighboring first water pipe 33, then from the first water pipe 33 into the upper horizontal circulation pipe 35 to enter the second water pipe 33, which then flows into lower horizontal circulation pipe 35 to enter the third water pipe 33. Under the action of the water pump, the water thus circulates and eventually comes out from the main out-bound pipe 34′ to the cooling box. The water is cooled in the cooling box and then recirculated to the in-bound main pipe as described above to repeat the cycles. A water outlet valve 30 is disposed on the inner wall of the vibration plate 21. The water outlet valve 30 includes a spring 38. The water outlet 36 of the water outlet valve 30 is connected with the water outlet path 37 of the vibration plate 21. If the water outlet valve 30 is open, water will spray out to soak the dirt nearby and reduce its hardness. If necessary, one can operate the vibrator 29. Under the actions of vibration and water soaking, pressing-in or pulling-out the main body 5 would be easy. The electric cable 31, sir duct 21, and water pipe 33 are all fixed inside the vibration chamber 21 on the outside walls of the long side 15/15′ of the main body 5 and the drawer box 22. The number of the electric cable 31 depends on the requirements of the vibrator 29 or other devices. In operation, the electric vibrator 29 generates a large amount of heat and needs water cooling. In contrast, air source vibrator 29 would not need cooling water or electrical supply, and this is a safer option for a vibrator. The functions of the vibrator 29 is to generate vibration force and vibration magnitude, which can assist with the pressing-in or pulling-out of the main body 5 by decreasing friction or assist to compact the concrete.
Uses of a device of the invention include three technical aspects: adjusting variable-pitch principles and applications, prefabrication of wall shoes, and mechanical connection to encircle the wall.
(1) variable pitch adjustment principles and applications: based on the actual distance between two front and rear wall-forming devices, the drawer box 22 is moved to the proper position on the ground to start the assembly. If the actual distance between the two wall-forming devices already pressed-into underground is within the fine adjustment range of the drawer box 22, then one only needs to move the drawer box 22 axially for a corresponding distance and there is no need to added the assembled outer box body 7′. Therefore, the drawer box 22 and the vibration plate 21 have their own fine-tuning characteristics for any pitch. Understanding this feature, one can assemble a variable-pitch wall-forming device with many variable pitch parameters, using a combination of the fixed-size assembled outer box 7′ and the vibrating plate 21+drawer box 22.
(2) Wall shoe 3 prefabrication: the wall shoe 3 is produced based on the final axial dimension at the bottom of the wall-forming device. This information was not available before-hand. However, in actual use, continuous pre-fabrication work is required to be carried out in advance. Based on experience, the axial size of the wall shoe 3 is estimated. When prefabricating step 26, the cross-sectional area should rather be larger than smaller. A larger cross section does not affect the use, and the increase in the area of the press-in end is insignificant. The cross section of the slope 25 should be small. A large cross-section of slope 25 may make it difficult to fit in the main body 5+drawer 22 cavity. A small cross-section of slope 25 can be filled in with hard and dry concrete or other fill material and it would be ready to use.
(3) Mechanical connection closure: When the drawer box 22 of the variable-pitch wall-forming device moves axially, the short side 23 of the drawer box 22 moves along with it. The inner short side 23 plays an important role in resisting the strong bracing stress of the multi-functional wall-clamping device and prevents deformation of the long side 15 of the main body. Because the location of the short side 23 of the drawer box 22 in the inner cavity of the main body 5 is not fixed, based on the cavity size divided by the main body 5 and the short side 23 of the drawer box, two reinforcing steel cages are respectively arranged in the cavities of the main body 5 and the drawer box 22 to enhance the rigidity of underground continuous wall. The variable-pitch wall forming device provides mechanical connection of the press-fit wall during the final closure. It connects the first closed press-fit wall-forming device at one end and the last press-fit wall-forming device at the other end. One needs to control the process sequence: Step 1, along the same axis, the dovetail track 11 of the variable-pitch wall-forming device should align with the dovetail trough 10 on the closed wall-forming device, while the dovetail trough 10 of the variable-pitch wall-forming device should align with the dovetail track 11 of the adjacent last wall-forming device. Step 2: couple the variable-pitch wall-forming device with the two connects on the two previously press-in underground wall-forming devices, and gradually press into the ground to a predetermined depth, thereby completing the final mechanical connections for encircling the press-fit wall. Step 3: first, pour concrete into the first closed wall-forming device and gradually pull out the device. Step 4: pour concrete into the last wall-forming device and gradually pull out the device. Step 5: pour concrete into the variable-pitch wall-forming device and gradually pull out the device. The press-fit underground wall is eventually completed without gaps.
| Number | Date | Country | Kind |
|---|---|---|---|
| 201510437161.1 | Jul 2015 | CN | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/CN2015/088116 | 8/26/2015 | WO | 00 |
