A top-down construction device and method

Abstract

The application provides a cover-excavation top-down construction device and a construction method, and belongs to the technical field of engineering construction. When the cover-excavation top-down construction method is used, more columnar pile foundations are needed to meet the supporting capacity, and the differential settlement between the columnar pile foundations will become obvious. The cover-excavation top-down construction device and the construction method comprise a base, a pulling-out mechanism, a segment-removing mechanism, a clamping mechanism and an anchor device. The base comprises a fixed seat and a movable seat. The movable seat is provided with a column hole and a sleeve hole. The movable seat can be translated in the fixed seat to adjust the position, so as to adjust the axis offset of the column hole and the column. The pulling-out mechanism, the segment-removing mechanism and the clamping mechanism can be matched to recycle and turnover the auxiliary sleeve group in the columnar pile. After recycling, the sleeve hole is provided with the anchor device, the anchor cable of the columnar pile is tensioned by the anchor device, and the tension is formed. Through the cooperation of the base and the anchor device, the differential settlement phenomenon between the multiple columnar pile foundations can be effectively controlled, and the engineering quality is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of engineering construction, and particularly relates to a top-down construction device and method for top-down construction. BACKGROUND

[0002] In the process of underground engineering construction, in order to reduce the influence on ground traffic, the top-down construction method is often used. The top-down construction method is a method that first constructs the columns, beams and roof of the underground engineering, then restores the ground traffic on the upper part, and excavates the soil and constructs the main underground engineering on the lower part.

[0003] For super-wide and super-large underground engineering, more column piles are needed to meet the supporting capacity. However, when the number of column piles increases, the differential settlement between the column piles will become serious, which will affect the safety and feasibility of the top-down construction method. Moreover, for super-deep engineering, the underground water in the main engineering range is relatively abundant, and the bottom plate of the main engineering is subjected to a large buoyancy, so that the anti-floating and stress problems cannot be solved by the main structure itself during construction.

[0004] In order to solve the anti-floating and stress problems of the column piles, the applicant adopts a new construction method. In the new construction method, the columns of the column piles need to be supported and adjusted, so anchor cables, anchor devices and more sleeve groups that play an auxiliary role are used. These sleeve groups are located in the column piles, and if they are not recycled, the cost of the construction project will increase. SUMMARY

[0005] In view of the above-mentioned shortcomings of the prior art, the purpose of the present application is to provide a top-down construction device and method, wherein the construction device is used to recycle the auxiliary parts used in the new construction method and adjust the differential settlement between the column piles, so as to solve the problems of high cost and serious differential settlement between the column piles in the prior art due to the use of more column piles and corresponding auxiliary parts in super-wide and super-large underground engineering.

[0006] In order to achieve the above-mentioned purpose and other related purposes, the present application provides a top-down construction device and method.

[0007] The top-down construction device is used to assist in constructing column piles, the column pile includes a column and a pile body, the pile body penetrates into the underground soil layer from the bottom of the foundation pit, the column bottom is inserted into the top of the pile body, and the column top is located on the ground surface. The top-down construction device is used to recycle the sleeve group used in the construction process and adjust the column. The sleeve group is formed by threadedly connecting a plurality of sleeve segments, and includes:

[0008] The base, the pulling mechanism, the segmenting mechanism, the clamping mechanism and the anchor device;

[0009] The base is installed at the pile head of the column pile on the ground surface, the base comprises a fixed seat and a movable seat, the movable seat is located inside the fixed seat, the fixed seat is fixedly connected with the ground surface, the movable seat is provided with a column hole and a casing hole, the column and the casing group pass through the column hole and the casing hole respectively, and the movable seat can be translated in the fixed seat to adjust the position and thus adjust the axis of the column hole;

[0010] The pulling mechanism comprises a clamping seat and an action mechanism, the clamping seat can loosen or clamp the casing segment, the action mechanism drives the clamping seat to reciprocate along the axis of the casing group and pull out the casing, the segmenting mechanism removes the casing segment at the uppermost end of the casing group from the casing group, and the clamping seat is clamped and fixed by the pulling mechanism, and the clamping mechanism clamps and fixes the remaining part of the casing group;

[0011] After the segmenting mechanism and the clamping mechanism are removed, the anchor device can be installed in the casing hole to tension the anchor cable connected at both ends of the column pile.

[0012] Optionally, the base further comprises four adjusting rods, the adjusting rod comprises a rod body and a sliding block, one end of the rod body is rotationally connected with the sliding block, and the other end is provided with an adjusting thread;

[0013] Four directions of the fixed seat and the movable seat are connected through the adjusting rods respectively, the sliding block is slidingly connected with the movable seat, and the adjusting thread is matched with an adjusting screw hole of the fixed seat.

[0014] Optionally, the action mechanism comprises a sliding table, a pulling rod, a first push rod and a second push rod;

[0015] The sliding direction of the sliding table is towards the axis of the casing group, one end of the pulling rod is rotationally connected with the sliding table, and the clamping seat is rotationally connected with the other end of the pulling rod;

[0016] The first push rod is vertically arranged, the tail end of the first push rod is fixedly arranged on the sliding axis of the sliding table and close to the casing group, and the output shaft end of the first push rod is rotationally and slidingly connected with the pulling rod;

[0017] The tail end of the second push rod is rotationally arranged on the pulling rod, the output shaft end of the second push rod is rotationally connected with the clamping seat, and the rotational axis is parallel to the rotational axis of the connection between the pulling rod and the clamping seat.

[0018] Optionally, the sliding table comprises a sliding seat, a sliding plate and a first power source, the sliding seat is provided with a rack, the first power source is fixedly arranged on the sliding plate, the output power of the first power source is transmitted to the rack through a gear, and the pulling rod is rotationally connected to the sliding plate.

[0019] Optionally, the segment disassembling mechanism comprises a second power source and a locking ring, the inner ring of the locking ring is matched with the casing segment, the locking ring can loosen or clamp the casing segment, and the outer ring of the locking ring is connected with the second power source and obtains rotary power.

[0020] Optionally, the clamping mechanism comprises a mounting seat and a clamp, the mounting seat is fixedly mounted on the movable seat, the clamp is fixedly mounted in the mounting seat, the clamp is provided with a clamping hole through which the casing segment passes, and the axis of the clamping hole coincides with the axis of the casing hole.

[0021] The clamping seat, the locking ring and the clamp are all clamped by electromagnets.

[0022] Optionally, the anchor tool comprises an anchor plate and a clamping piece, the anchor plate is fixedly connected to the movable seat, a plurality of anchor holes are arranged on the anchor plate, and the clamping piece is located in the anchor hole.

[0023] Optionally, a casing rack is further arranged, the casing rack is arranged outside the base and opposite to the pulling-out mechanism, and the casing rack comprises a receiving layer and a storage layer.

[0024] The receiving layer is located on the upper layer, the receiving layer is arranged in an inclined manner along the axis direction of the casing segment, the receiving layer is also arranged in an inclined manner along the rolling direction of the casing segment, and the lower side is provided with a material passing gap, and the cross-sectional width of the material passing gap is greater than the diameter of the casing segment.

[0025] The storage layer is located on the lower layer, the storage layer is arranged in an inclined manner along the rolling direction of the casing segment, and the side of the material passing gap is the higher side.

[0026] The construction method of the top-down excavation method comprises the following steps by using the construction device:

[0027] The pile hole drilling step is to perform the pile hole construction of the diaphragm wall and the column pile according to the design specification, to arrange the top-down excavation method construction device at the ground surface of the column pile, and to make the axis of the column hole coincide with the axis of the pile hole.

[0028] The casing group entering hole step is to put the casing group into the casing hole, the bottom of the casing group is flush with the bottom of the pile hole, the top of the casing group exceeds the casing hole, and a small hole drilling machine is used to continue drilling the anchor cable hole with a set depth along the casing group at the bottom of the pile hole.

[0029] anchor cable insertion step, inserting anchor cables from the casing hole, the anchor cables passing through the pile hole to the bottom of the anchor cable hole, the anchor cables being located in the casing group within the range of the pile hole;

[0030] grouting step, grouting the anchor cable hole and the pile hole, the grouting depth being flush with the bottom of the foundation pit, the end of the anchor cable being solidified in the anchor cable hole, the bottom of the column being inserted into the pile hole grout to a specified depth, the top of the column being fitted into the column hole of the movable seat and the movable seat supporting the column;

[0031] casing group recovery step, after the grout of the column pile hardens to a specified degree, the casing group is recovered by the top-down excavation construction device;

[0032] anchor cable fixation step, the top end of the anchor cable is anchored on the movable seat by the anchor device;

[0033] first layer excavation step, hardening and restoring the ground, excavating the first layer of soil of the foundation pit, constructing the corbel, erecting the horizontal support inside the corbel, the horizontal support being erected on the column, the column bearing the structural load of the constructed part, then monitoring the displacement of each column pile, adjusting the horizontal displacement by the movable seat and adjusting the vertical displacement by pulling the anchor cable, ensuring that the settlement difference of each column pile meets the standard;

[0034] second layer excavation step, excavating the second layer of soil of the foundation pit and constructing the second layer of horizontal support, which is also erected on the column, the column bearing the structural load of the constructed part, adjusting the horizontal and vertical displacement according to the method in the previous step;

[0035] bottom layer excavation step, the construction is repeated until the bottom of the foundation pit is excavated, the main bottom plate is constructed as soon as possible, then the main concrete structure is constructed upwards in turn, according to the calculation, when the gravity distributed to the column pile is basically the same as the anchor cable tension, it indicates that the weight of the main structure is sufficient to balance the anchor cable anchoring force, at this time, the anchor cable anchoring force is reduced, and the permanent anchoring is performed at a specified value;

[0036] permanent anchoring step, the anchor cable and the anchor device are poured into the main structure, and the remaining structure is constructed according to the conventional method.

[0037] Optionally, in the casing group hole insertion step, when the casing group is inserted, the outer layer of the casing group is sheathed with a sheath layer.

[0038] As described above, the top-down excavation construction device and the construction method of the present application have at least the following beneficial effects:

[0039] The construction device can reduce construction cost and improve engineering quality. Specifically, the construction device comprises a base, a pulling-out mechanism, a segmenting mechanism, a clamping mechanism and an anchor device. The base comprises a fixed seat and a movable seat. The movable seat is provided with a stand column hole and a sleeve hole. The movable seat can be translated in the fixed seat to adjust the position, so as to adjust the axis offset of the stand column hole and the stand column. The pulling-out mechanism, the segmenting mechanism and the clamping mechanism can cooperate with each other to recycle the auxiliary sleeve group in the stand column pile. After the sleeve group is recycled, the anchor device can be installed in the sleeve hole. The anchor device can tension the anchor cable at both ends of the stand column pile to form internal stress and improve the pull-out performance of the stand column pile. Through the cooperation of the movable seat and the anchor device, the differential settlement phenomenon between the stand column piles can be effectively controlled, and the engineering quality can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0040] Figure 1 The construction device is shown as a whole schematic diagram.

[0041] Figure 2 The construction device is shown as a whole schematic diagram.

[0042] Figure 3 The construction device is shown as a whole schematic diagram. Figure 2 The construction device is shown as a whole schematic diagram.

[0043] Figure 4 The construction device is shown as a whole schematic diagram.

[0044] Figure 5 The construction device is shown as a whole schematic diagram. Figure 4 The construction device is shown as a whole schematic diagram.

[0045] Figure 6 The construction device is shown as a whole schematic diagram. Figure 4 The construction device is shown as a whole schematic diagram.

[0046] Figure 7 The construction device is shown as a whole schematic diagram.

[0047] Figure 8 The construction device is shown as a whole schematic diagram.

[0048] Figure 9 The construction method is shown as a whole schematic diagram.

[0049] Figure 10 The construction method is shown as a whole schematic diagram.

[0050] Figure 11 The construction method is shown as a whole schematic diagram.

[0051] Figure 12 The construction method is shown as a whole schematic diagram.

[0052] Figure 13 The figure shows the state after the bottom excavation step in the construction method of the present application.

[0053] Figure 14 The figure shows a single column pile in the construction method of the present application.

[0054] Figure 15 The figure shows the D-D cross section in the construction method of the present application. Figure 14

[0055] The figure shows the E-E cross section in the construction method of the present application. Figure 16 Figure 14 The figure shows the E-E cross section in the construction method of the present application.

[0056] Wherein: base 1, fixed seat 10, movable seat 11, adjusting rod 12, rod body 121, adjusting screw 1211, sliding block 122, pulling-out mechanism 2, clamping seat 20, sliding table 21, sliding seat 210, rack 2100, sliding plate 211, first power source 212, gear 2121, pulling rod 22, first push rod 23, second push rod 24, segment dismounting mechanism 3, second power source 30, locking ring 31, clamping mechanism 4, mounting seat 40, clamp 41, anchor 5, anchor plate 50, anchor hole 501, clamping piece 51, anchor cable 52, sleeve rack 6, material receiving layer 60, material passing gap 601, material storage layer 61, diaphragm wall 71, horizontal support 72, main body bottom plate 73, column 90, pile body 91, sleeve group 92, sleeve segment 921, sheath layer 922, anchor cable hole 93. DETAILED DESCRIPTION

[0057] The following specific embodiments illustrate the embodiments of the present application, and those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in the specification.

[0058] Please refer to Figures 1 to 16 . It should be understood that the structure, proportion, size, etc. shown in the drawings of the specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the defined conditions that the present application can be implemented, so they do not have technical significance. Any modification of the structure, change of the proportion relationship or adjustment of the size, without affecting the effects that the present application can produce and the purposes that the present application can achieve, should still fall within the scope covered by the technical content disclosed by the present application. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" used in the specification are only for the convenience of clear description, and are not used to limit the scope of the present application, the change or adjustment of the relative relationship, without substantially changing the technical content, is also considered as the implementation of the present application.

[0059] ​The following embodiments are merely exemplary. Various embodiments can be combined, which are not limited to the following single embodiment.

[0060] Referring to Figure 1 and Figure 2 , the present application provides a top-down construction device for assisting in the construction of a column pile. The structure of the column pile can be seen in Figure 14 , which includes a column 90 and a pile body 91. During construction, a bottom hole of the column pile is first drilled. The bottom hole of the column pile includes a foundation pit area and a cast-in-place pile body area, in combination with Figure 9 , the height H1 of the foundation pit is the main depth range of the underground building structure, and H2 is the pile body area of the cast-in-place pile, which is deep into the soil layer from the bottom of the foundation pit. In subsequent construction, the cast-in-place pile body area of the bottom hole will be filled with concrete slurry, thereby forming the pile body 91. The pile body 91 is deep into the underground soil layer from the bottom of the foundation pit, and the pile body 91 is the bearing foundation of the underground building structure. Before the pile body 91 is solidified after being cast, the column bottom of the column 90 is inserted into the top of the pile body 91, that is, the area of H4 in Figure 9 , Figure 16 shows the E-E cross section of the inserted part in Figure 14 . The top of the column 90 is located on the ground surface. During the solidification process of the concrete slurry, the part of the column 90 inserted into the pile body 91 will gradually solidify into a whole with the concrete slurry. In subsequent construction, as the main body of the underground building structure is completed, the load of the main body of the underground building structure will gradually be loaded to the pile body 91 through the column 90.

[0061] Therefore, in the process of engineering construction, for ultra-wide, ultra-large, and ultra-deep underground projects, more column pile foundations are needed to meet the supporting capacity. When the number of column pile foundations increases, the differential settlement phenomenon between the column pile foundations will become serious. Moreover, if the underground water in the main body range of the project is relatively abundant, the buoyancy of the main body of the project is large, and the anti-floating and stress problems during construction and operation cannot be solved only by the frame of the main body itself. Therefore, the applicant adopts a new construction scheme, that is, the anchor hole is drilled into the bottom of the column pile, that is, the depth of H3 in Figure 9 , the anchor cable 52 is connected to the ground surface, and the tension of the anchor cable 52 is adjusted to adjust the tension between the pile bottom and the pile top. For multiple column piles, different tension amounts can be set according to the settlement differences of each column pile, thereby reducing the differential settlement and improving the safety of construction and the reliability of the main structure.

[0062] The anchor cable 52 needs to penetrate the pile body 91 and reach the bottom of the pile body 91. Since the pile body 91 is cast in concrete, a sleeve assembly 92 is installed in the pile body 91. The sleeve assembly 92 forms a grout isolation zone in the pile body 91 for the anchor cable to pass through. When the pile body 91 is poured with concrete, the anchor cable 52 will not be poured inside. After the concrete of the pile body 91 has solidified to a certain extent, the sleeve assembly 92 can be recycled and reused to reduce costs, while the anchor cable is placed in the hole formed by the original sleeve assembly 92.

[0063] Before the concrete of the pile body 91 is completely solidified, the column 90 needs to be inserted into the pile body 91. At this time, the concrete grout in the pile body 91 cannot fully support the column 90. Therefore, the column 90 needs to be externally supported at the top of the pile hole. If necessary, the column 90 also needs to be adjusted to ensure that its axis coincides with the axis of the pile hole, so as to ensure the construction quality of the column pile.

[0064] Furthermore, this cut-and-cover reverse construction device is used to recover the casing assembly 92 used in the construction process and adjust the verticality of the column 90. After the casing assembly 92 is recovered, the anchor 5 can also be installed in the casing hole to tension the anchor cable 52 connected to both ends of the column pile, thereby adjusting the tension at the top of each column pile and improving the differential settlement between multiple column piles.

[0065] Generally speaking, combined Figure 9 The depth of the main structure of a typical underground building is approximately 30 meters, as shown by height H1 in the diagram. The pile body 91 of the column pile extends 30 meters further from the bottom of the main structure, as shown by height H2 in the diagram. In this invention, the anchor cable hole 93, used to fix the anchor cable, extends further underground from the bottom of the pile body 91, as shown by height H3 in the diagram. Therefore, the casing assembly 92 used to isolate the concrete slurry of the column pile can extend approximately 60 meters from the ground surface to the bottom of the pile body 91. Without proper retrieval, this would result in significant material waste. If a single-tube installation is used, the maximum vertical height of the casing assembly 92 from the ground surface during extraction would reach 60 meters, placing extremely high demands on the extraction equipment and posing a potential hazard. Furthermore, the storage and transportation of the extracted casing assembly 92 would also present problems. Therefore, in this embodiment, the casing assembly 92 is composed of multiple casing segments 921 connected by threads. Each segment can be approximately 2-3 meters long, facilitating extraction and convenient storage and transportation after extraction.

[0066] Specifically, please refer to Figure 1 , Figure 2 and Figure 8 The device includes a base 1, a pull-out mechanism 2, a segmentation mechanism 3, a clamping mechanism 4, and an anchor 5;

[0067] The base 1 is installed on the pile head of the pile column on the ground surface, and comprises a fixed seat 10 and a movable seat 11. The movable seat 11 is located inside the fixed seat 10, and the fixed seat 10 is fixedly connected with the ground surface. The movable seat 11 is provided with a pile hole and a sleeve hole. The pile 90 and the sleeve group 92 pass through the pile hole and the sleeve hole respectively. The movable seat 11 can be adjusted in position in the fixed seat 10, so as to adjust the axis of the pile hole. Before the concrete in the pile column is solidified, the lower end of the sleeve group 92 is supported on the bottom of the pile hole, and the upper end passes through the sleeve hole to be stable. The bottom of the pile 90 is inserted into the concrete slurry, and the upper end passes through the pile hole and is hung on the movable seat 11 by the protruding structure at the upper end of the pile 90. The movable seat 11 is installed on the ground structure. When the movable seat 11 moves horizontally, the axis of the pile hole on the movable seat 11 changes, so as to adjust the axis of the pile 90. The verticality of the pile 90 can be effectively improved. Especially during the solidification process of the concrete slurry into which the pile 90 is inserted, the pile 90 can always be vertical and is not affected by the change of the supporting effect of the pile 90 caused by the stress change during the solidification process of the concrete slurry.

[0068] The pulling-out mechanism 2 comprises a clamping seat 20 and a driving mechanism. The clamping seat 20 can loosen or clamp the sleeve segment 921. The driving mechanism drives the clamping seat 20 to reciprocate along the axis of the sleeve group 92 and pull out the sleeve. The segment removing mechanism 3 removes the uppermost sleeve segment 921 of the sleeve group 92 from the sleeve group 92, and the clamping seat 20 clamps and fixes the sleeve segment 921. The clamping mechanism 4 clamps and fixes the remaining part of the sleeve group 92. Specifically, the pulling-out process is as follows:

[0069] Firstly, the pulling-out mechanism 2 clamps and pulls up the sleeve group 92. After pulling out a distance, the clamping mechanism 4 on the lower side clamps the sleeve group 92.

[0070] Then, the pulling-out mechanism 2 loosens and moves down the sleeve group 92. After moving to a suitable position, the sleeve group 92 is clamped again, and then the clamping mechanism 4 loosens the sleeve group 92.

[0071] Then, the pulling-out mechanism 2 pulls up again, and the above process is repeated until the uppermost sleeve segment 921 is completely pulled out.

[0072] The clamping mechanism 4 clamps the sleeve group 92 again. At this time, the clamping point is lower than the uppermost sleeve segment 921. The pulling-out mechanism 2 loosens the sleeve group 92, and the segment removing mechanism 3 clamps and removes the uppermost sleeve segment 921.

[0073] The pulling-out mechanism 2 clamps the uppermost sleeve segment 921 again, and the segment removing mechanism 3 loosens the uppermost sleeve segment 921. At this time, the sleeve segment 921 can be taken away.

[0074] The above steps are repeated to complete the recycling work of the sleeve group 92.

[0075] After the recovery work of the casing group 92 is completed, the pulling mechanism 2, the segmenting mechanism 3 and the clamping mechanism 4 can be removed from the movable seat 11, and then the anchor device 5 is replaced, and the anchor cable is connected to the anchor device 5. In summary, the movable seat 11 plays a supporting and axis adjusting effect on the column 90, and the anchor cable of the column pile is tensioned through the anchor device 5 on the movable seat 11, thereby providing a downward pulling force, which can adjust the verticality of a single column 90 and control the settlement difference between multiple column piles. The device body can also recover the casing group 92. In general, the construction quality of a single column pile, the settlement consistency between multiple column piles, the construction cost and the construction efficiency are improved.

[0076] The embodiment can refer to Figure 4 and Figure 6 The base 1 further comprises four adjusting rods 12, the adjusting rod 12 comprising a rod body 121 and a sliding block 122, the rod body 121 being rotatably connected to the sliding block 122 at one end and being provided with an adjusting screw thread 1211 at the other end. The four directions of the fixed seat 10 and the movable seat 11 are connected through the adjusting rods 12, the sliding block 122 being slidingly connected to the movable seat 11, and the adjusting screw thread 1211 being matched with the adjusting screw hole of the fixed seat 10. In this embodiment, after the column 90 is inserted into the pile body 91, before the concrete is completely solidified, the movable seat 11 supports the column 90, and the distance between the movable seat 11 and the fixed seat 10 can be adjusted by rotating the rod body 121. The position of the movable seat 11 can be adjusted through the four adjusting rods 12 in four directions, and the axis of the column 90 is adjusted, so that the axis of the column 90 coincides with the axis of the pile body 91.

[0077] The embodiment can refer to Figure 4 The action mechanism comprises a sliding table 21, a pulling rod 22, a first push rod 23 and a second push rod 24. The sliding direction of the sliding table 21 is towards the axis of the casing group 92, one end of the pulling rod 22 is rotatably connected to the sliding table 21, and the clamping seat 20 is rotatably connected to the other end of the pulling rod 22; the first push rod 23 is vertically arranged, the tail end of the first push rod 23 is fixedly arranged on the sliding axis of the sliding table 21 and close to the casing group 92, and the output shaft end of the first push rod 23 is rotatably and slidingly connected to the pulling rod 22; the tail end of the second push rod 24 is rotatably arranged on the pulling rod 22, the output shaft end of the second push rod 24 is rotatably connected to the clamping seat 20, and the rotation axis is parallel to and does not coincide with the rotation axis of the connection between the pulling rod 22 and the clamping seat 20.

[0078] In the above embodiment, in the pulling-out stage, the casing string 92 is located in the casing hole, after the clamping seat 20 clamps the casing string 92, when the sliding table 21 moves towards the base 1, the casing string 92 cannot move in the same direction due to the limiting effect of the casing hole, the pushing force of the sliding table 21 on the pulling rod 22 is converted into the upward movement of the clamping seat 20 along the axis of the casing string 92, thereby pulling out the casing string 92. The first push rod 23 can also be extended to lift the clamping seat 20, thereby achieving the pulling-out effect. After the last casing segment 921 of the casing string 92 is removed, the first push rod 23 and the sliding table 21 can be used to form the pitching action of the clamping seat 20 relative to the pulling rod 22 by pushing and pulling the clamping seat 20, thereby changing the casing segment 921 from a vertical state to a horizontal state, thereby facilitating the removal of the casing segment 921. The length of the pulling rod 22 is relatively long, which can increase the pulling-out amount at a time, thereby improving the pulling-out efficiency. The first push rod 23 supports the cantilever of the pulling rod 22, thereby improving the strength.

[0079] Further, please refer to Figure 5 The sliding table 21 includes a sliding seat 210, a sliding plate 211 and a first power source 212, the sliding seat 210 is provided with a rack 2100, the first power source 212 is fixedly arranged on the sliding plate 211, the output power of the first power source 212 is transmitted to the rack 2100 through a gear 2121, and the pulling rod 22 is rotationally connected to the sliding plate 211. The sliding of the sliding table 21 is realized by a gear and rack mechanism, a plurality of sliding seats 210 are pre-fixed to the floor, after the pulling-out of the casing string 92 in one direction is completed, the first push rod 23 and the sliding plate 211 are disassembled and installed in the sliding seat 210 in another direction, thereby quickly completing the switching of the workstations, thereby improving the construction effect and simplifying the construction process. At the same time, compared with the traditional air pressure and electric push rod, the volume is smaller, there is no invalid volume part, the first power source 212 can slide with the sliding plate 211 in the rack range of the entire sliding seat 210, while the traditional push rod mechanism has an invalid length such as a shell, which may have difficulty in implementation in a space-limited construction site.

[0080] Please refer to Figure 3, the disassembling mechanism 3 comprises a second power source 30 and a locking ring 31, the inner ring of the locking ring 31 matches the casing segment 921, the locking ring 31 can loosen or clamp the casing segment 921, the outer ring of the locking ring 31 is connected with the second power source 30 and obtains rotating power. In the pulling-out stage, the locking ring 31 loosens the casing group 92, the casing group 92 can slide along the axis thereof, when disassembling is needed, the clamping mechanism 4 clamps the casing group 92, the clamping position is lower than the connection position of the uppermost casing segment 921 and the casing group 92, the locking ring 31 clamps the uppermost casing segment 921, then the second power source 30 drives the locking ring 31 to rotate, and the uppermost casing segment 921 is disassembled from the casing group 92. After disassembling is completed, the casing segment 921 is clamped by the pulling-out mechanism 2, and then the casing segment 921 is placed horizontally for taking down after the locking ring 31 is loosened.

[0081] Further, the clamping mechanism 4 comprises a mounting seat 40 and a clamping device 41, the mounting seat 40 is fixedly installed on the movable seat 11, the clamping device 41 is fixedly installed in the mounting seat 40, the clamping device 41 is provided with a clamping hole through which the casing segment 921 passes, and the axis of the clamping hole coincides with the axis of the casing hole. The device has simple structure, high efficiency, convenient quick disassembling and quick assembling, can improve construction efficiency, and is reliable in operation and not prone to failure. The clamping seat 20, the locking ring 31 and the clamping device 41 are all clamped by electromagnets.

[0082] The embodiment can refer to Figure 8 , the anchorage device 5 comprises an anchor plate 50 and a clamping piece 51, the anchor plate 50 is fixedly connected to the movable seat 11, the anchor plate 50 is provided with a plurality of anchor holes 501, and the clamping piece 51 is located in the anchor hole 501. The anchorage device 5 is installed after the casing group 92 is disassembled, the anchorage device 5 can be installed by means of the casing hole and the mounting hole of the clamping mechanism 4, after the anchorage device 5 is installed, the end of the anchor cable is tensioned to form a downward pulling force on the column 90, after the settlement of each column pile is measured, or according to the load change of each column pile calculated according to the construction progress during the construction process, the pulling force of the anchor cable on each column pile can be adjusted in time, which can reduce the settlement difference on one hand and improve the stress condition of the pile body on the other hand, thereby improving the engineering quality.

[0083] The embodiment can refer to Figure 1 and Figure 7 , further comprising a casing rack 6, the casing rack 6 is arranged outside the base 1 and opposite to the pulling-out mechanism 2, and the casing rack 6 comprises a receiving layer 60 and a storage layer 61. The receiving layer 60 is located at the upper layer, the receiving layer 60 is arranged obliquely along the axis direction of the casing segment 921, the receiving layer 60 is also arranged obliquely along the rolling direction of the casing segment 921, and the lower side is provided with a material passing gap 601, the cross-sectional width of the material passing gap 601 is greater than the diameter of the casing segment 921; the storage layer 61 is located at the lower layer, the storage layer 61 is arranged obliquely perpendicular to the axis direction of the casing segment 921, and the higher side is on one side of the material passing gap 601.

[0084] In the above embodiment, the casing support 6 cooperates with the pulling mechanism 2 to realize the automatic unloading process, avoiding manual intervention, thus accelerating the construction efficiency and improving the construction quality. Specifically, through the two-way inclined surface of the receiving layer 60, when the pulling mechanism 2 tilts the casing segment 921 onto the casing support 6 and releases it, the casing segment 921 automatically slides into the receiving layer 60 along the axial direction, rolls towards the overpass gap 601 at the lower side of the receiving layer 60, and automatically enters the storage layer 61. Through the inclination of the storage layer 61, the casing segment 921 is automatically stacked from the lower side. The casing support 6 is also provided with universal rollers at the bottom, facilitating the transportation of the casing support 6 and the casing segments 921 stored therein, greatly reducing the amount of manual labor, and improving the construction efficiency and safety.

[0085] The present embodiment refers to Figures 9-14 , which provides a top-down construction method, which can use the construction device as described above, including the following steps.

[0086] Pile hole drilling step: according to the design specification, the pile hole construction of the diaphragm wall 71 or other types of enclosure structures and column piles is carried out, including the foundation pit area height H1 and the pile body area height H2. After drilling, the reinforcement cage and other materials of the cast-in-place pile are placed, and then the top-down construction device is installed at the ground surface pile opening of the column pile, and the axis of the column hole coincides with the axis of the pile hole;

[0087] Casing group into hole step: the casing group 92 is placed into the casing hole, the bottom of the casing group 92 is flush with the bottom of the pile hole, i.e., reaches the lower line depth of the pile body area, and the top of the casing group 92 exceeds the casing hole to facilitate clamping during subsequent pulling and recycling. The casing group 92 can also be bundled on the reinforcement cage of the cast-in-place pile and lowered into the pile hole together with the reinforcement cage of the cast-in-place pile. Then, a small hole drilling machine is used to continue drilling an anchor hole 93 with a set depth H3 along the bottom of the casing group 92 in the pile hole. In specific implementation, the casing group 92 can be placed first, and the drilling machine can be drilled down from the casing group 92, or the hole can be drilled first and then the casing group 92 is placed. Regardless of the order of the steps, the anchor hole 93 and the casing group 92 must be aligned to facilitate the placement of the anchor cable 52 from the casing group 92 into the anchor hole 93.

[0088] Anchor cable placement step: the anchor cable 52 is placed into the casing hole, and the anchor cable 52 passes through the pile hole to the bottom of the anchor hole. In the range of the pile hole, the anchor cable 52 is located in the casing group 92, and in the range of the bottom of the pile hole, the anchor cable 52 is located in the anchor hole 93.

[0089] Grouting step: grouting is performed on the anchor hole and the pile hole, and the grouting depth of the pile hole is flush with the bottom of the foundation pit, please refer to Figure 9, that is, the grouting range of the pile hole is H2, and the grouting range of the anchor hole is H3. When grouting, the anchor hole needs to be grouted first. The pressure grouting method can be used to enhance the embedding performance of the grout and the soil layer around the anchor hole. The end of the anchor cable 52 is solidified in the anchor hole. Then, the pile hole is grouted. The anchor cable 52 is isolated by the casing group 92 to avoid the grout of the anchor cable 52 and the pile body from solidifying together, so that the anchor cable cannot be pulled out. The casing group 92 can also be appropriately raised to produce a suitable gap between the bottom of the casing group 92 and the bottom of the pile hole, expose the bottom end of the anchor cable 52 in the grout, and solidify the bottom end of the anchor cable 52 with the bottom end of the pile body 91, thereby further increasing the firmness of the end of the anchor cable 52. However, in this way, due to the gap at the end of the casing group 92, a sealing structure needs to be provided at the end of the casing group 92 to prevent the grout from flowing back into the casing group 92 from the gap, so that the purpose of this method cannot be achieved. After the grout in the pile body 91 solidifies to a suitable degree, the bottom end of the column 90 is inserted into the top of the grout in the pile hole to a specified depth, that is, the range of H4, and the top of the column 90 is matched with the column hole of the movable seat 11, and the movable seat 11 supports the column 90. During the supporting process, the axis of the column 90 can also be adjusted to improve the construction accuracy of the column 90.

[0090] Casing group recovery step: after the grout of the column pile hardens to a specified degree, the casing group 92 is recovered using the cover-excavation top-down construction device. Since the anchor cable 52 is located in the casing group 92, attention should be paid to the treatment of the anchor cable during the recovery of the casing group 92 to prevent the anchor cable from falling to the bottom of the hole. After the recovery of the casing group 92 is completed, the upper end of the anchor cable 52 is anchored.

[0091] Anchor cable 52 fixing step: the top end of the anchor cable 52 is anchored on the movable seat 11 using the anchor 5. The initial anchoring tension can be set to 50 kN.

[0092] First layer excavation step: please refer to Figure 10 and Figure 11 , the ground is hardened and restored, the road traffic is restored accordingly, the first layer of soil in the foundation pit is excavated, the corbel is constructed, the horizontal support 72 is erected inside the corbel, the horizontal support 72 is erected on the column 90, the column 90 bears the structural load of the constructed part, then the offset of each column pile, including the axis offset and the settlement, is monitored in a timely manner, the horizontal offset is adjusted by the movable seat 11, and the vertical offset is adjusted by pulling the anchor cable 52 to ensure that the settlement difference of each column pile meets the standard. When pulling the anchor cable 52, the tension can be increased or decreased by 50 kN each time based on 50 kN.

[0093] Second layer excavation step: please refer to Figure 12, excavate the second layer of soil of the foundation pit, and construct the second layer of horizontal support 72, which is also erected on the column 90, and the column 90 bears the structural load of the constructed part, and the horizontal and vertical offset is adjusted according to the method in the previous step;

[0094] The bottom excavation step: please refer to Figure 13 , and the main body bottom plate 73 is constructed as soon as possible, and then the main body concrete structure is constructed upwards in turn. With the improvement of the main body structure, according to the calculation, when the gravity distributed to the column pile and the anchor cable 52 tension are basically the same, it is indicated that the main body structure weight is sufficient to balance the anchor cable 52 anchoring force, at this time, the anchoring force of the anchor cable 52 is reduced, and permanent anchoring is carried out with a set value, and a set value of 50kN can be used.

[0095] Permanent anchoring step: the end of the anchor cable 52 and the anchor device 5 are poured into the main body structure, and the remaining structure is constructed according to the conventional method.

[0096] Further, in the sleeve group into the hole step, when the sleeve group 92 is put in, the outer layer of the sleeve group 92 is sleeved with a sheath layer 922, so that the sleeve group 92 and the pouring area of the pile body 91 are isolated, and when the pile body 91 is poured, the concrete slurry cannot be directly contacted and solidified with the outer layer of the sleeve group 92, and when the sleeve group 92 is pulled out, there is no embedding force of the concrete, and the pulling-out process is more convenient.

[0097] As described above, the present application effectively overcomes the various shortcomings in the prior art and has high industrial utilization value.

[0098] The above examples only exemplarily illustrate the principles and effects of the present application, and are not used to limit the present application. Any person skilled in the art can modify or change the above examples without departing from the spirit and scope of the present application. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical thought disclosed by the present application should be covered by the claims of the present application.

Claims

1. A top-down construction device for assisting in the construction of a column pile, the column pile comprising a column (90) and a pile body (91), the pile body (91) penetrating into the underground soil layer from the bottom of a foundation pit, the bottom of the column (90) being inserted into the top of the pile body (91), and the top of the column (90) being located on the ground surface, the top-down construction device being used for recovering a casing group (92) used in the construction process and adjusting the column (90), the casing group (92) being formed by a plurality of casing segments (921) connected by threads, characterized in that, The device comprises a base (1), a pulling mechanism (2), a segment-removing mechanism (3), a clamping mechanism (4) and an anchor (5). The base (1) is installed on the pile head of the column pile on the ground surface, and comprises a fixed seat (10) and a movable seat (11). The movable seat (11) is located inside the fixed seat (10), the fixed seat (10) is fixedly connected with the ground surface, and the movable seat (11) is provided with a column hole and a sleeve hole. The column (90) and the sleeve group (92) pass through the column hole and the sleeve hole respectively. The movable seat (11) can be adjusted in position in the fixed seat (10), so as to adjust the axis of the column hole. The pulling mechanism (2) comprises a clamping seat (20) and a driving mechanism. The clamping seat (20) can loosen or clamp the sleeve segment (921). The driving mechanism drives the clamping seat (20) to reciprocate along the axis of the sleeve group (92) and pull out the sleeve segment (921). The segment-removing mechanism (3) removes the uppermost sleeve segment (921) of the sleeve group (92) from the sleeve group (92), and clamps and fixes the sleeve segment (921) by the pulling mechanism (2). The clamping mechanism (4) clamps and fixes the remaining part of the sleeve group (92). After the segment-removing mechanism (3) and the clamping mechanism (4) are removed, the anchor (5) can be installed in the sleeve hole, and the anchor cable (52) connected to both ends of the column pile is tensioned.

2. The device for top-down construction method according to claim 1, wherein the base (1) further comprises four adjusting rods (12), each of the adjusting rods (12) comprising a rod body (121) and a sliding block (122), one end of the rod body (121) being rotatably connected with the sliding block (122), and the other end of the rod body (121) being provided with an adjusting screw thread (1211). The four directions of the fixed seat (10) and the movable seat (11) are connected by the four adjusting rods (12) respectively. The sliding block (122) is slidably connected with the movable seat (11), and the adjusting screw thread (1211) is matched with the adjusting screw hole of the fixed seat (10).

3. The device for top-down construction method according to claim 1, wherein the driving mechanism comprises a sliding table (21), a pulling rod (22), a first push rod (23) and a second push rod (24). The sliding direction of the sliding table (21) is towards the axis of the sleeve group (92). One end of the pulling rod (22) is rotatably connected with the sliding table (21), and the other end of the pulling rod (22) is rotatably connected with the clamping seat (20). The first push rod (23) is vertically arranged. The tail end of the first push rod (23) is fixedly arranged on the sliding axis of the sliding table (21) and close to the sleeve group (92). The output shaft end of the first push rod (23) is rotatably and slidably connected with the pulling rod (22). ​ ​ ​ The tail end of the second push rod (24) is rotatably arranged on the pulling rod (22), and the output shaft end of the second push rod (24) is rotatably connected to the clamping seat (20), and the rotation axis is parallel to the rotation axis of the connecting part of the pulling rod (22) and the clamping seat (20).

4. A topdown method construction apparatus according to claim 3, wherein The sliding table (21) comprises a sliding seat (210), a sliding plate (211) and a first power source (212), the sliding seat (210) is provided with a rack (2100), the first power source (212) is fixedly arranged on the sliding plate (211), and the output power of the first power source (212) is transmitted to the rack (2100) through a gear (2121), and the pulling rod (22) is rotatably connected to the sliding plate (211).

5. A topdown construction method as claimed in claim 1, wherein The segment dismounting mechanism (3) comprises a second power source (30) and a locking ring (31), the inner ring of the locking ring (31) is matched with the sleeve segment (921), the locking ring (31) can loosen or clamp the sleeve segment (921), and the outer ring of the locking ring (31) is connected with the second power source (30) and obtains rotary power.

6. The construction device for top-down construction method according to claim 5, wherein: The clamping mechanism (4) comprises a mounting seat (40) and a clamp (41), the mounting seat (40) is fixedly mounted on the movable seat (11), the clamp (41) is fixedly mounted in the mounting seat (40), the clamp (41) is provided with a clamping hole through which the sleeve segment (921) passes, and the axis of the clamping hole coincides with the axis of the sleeve hole; The clamping seat (20), the locking ring (31) and the clamp (41) are all clamped through electromagnets.

7. A topdown construction method as claimed in claim 1, wherein The anchor device (5) comprises an anchor plate (50) and a clamping piece (51), the anchor plate (50) is fixedly connected to the movable seat (11), a plurality of anchor holes (501) are arranged on the anchor plate (50), and the clamping piece (51) is located in the anchor hole (501).

8. The construction device for top-down construction method according to claim 1, wherein: A sleeve rack (6) is further arranged outside the base (1) and opposite to the pulling-out mechanism (2), the sleeve rack (6) comprises a receiving layer (60) and a storage layer (61); The receiving layer (60) is located on the upper layer, the receiving layer (60) is arranged in an inclined manner along the axial direction of the sleeve segment (921), the receiving layer (60) is also arranged in an inclined manner along the rolling direction of the sleeve segment (921), and a material passing gap (601) is arranged on the lower side, the cross-sectional width of the material passing gap (601) is greater than the diameter of the sleeve segment (921); The storage layer (61) is located on the lower layer, the storage layer (61) is arranged in an inclined manner along the rolling direction of the sleeve segment (921), and the sleeve segment (921) is automatically stacked from the lower side by virtue of the inclination of the storage layer (61).

9. A top-down construction method characterized by comprising: The construction device according to claim 7 comprises the following steps: Pile hole drilling step, drilling pile holes for diaphragm wall (71) and the pile of the column (90) according to design specifications, installing the top-down construction device in the ground surface of the column pile, the axis of the column hole coincides with the axis of the pile hole; Casing group into hole step, putting the casing group (92) into the casing hole, the bottom of the casing group (92) is flush with the bottom of the pile hole, the top of the casing group (92) exceeds the casing hole, using a small hole drilling machine to drill an anchor hole (93) of a set depth along the casing group (92) at the bottom of the pile hole; Put in anchor step, put the anchor (52) into the casing hole, the anchor (52) passes through the pile hole to the bottom of the anchor hole (93), in the range of the pile hole, the anchor (52) is located in the casing group (92); Grouting step, grouting the anchor hole (93) and the pile hole, the grouting depth is flush with the bottom of the foundation pit, the end of the anchor (52) is solidified in the anchor hole (93), the bottom end of the column (90) is inserted into the grout of the pile hole to a set depth, the top of the column (90) is matched with the column hole of the movable seat (11), and the movable seat (11) supports the column (90); Casing group recovery step, after the grout of the column pile hardens to a set degree, the casing group (92) is recovered by using the top-down construction device; Anchor fixing step, using the anchor device (5) to anchor the top end of the anchor (52) on the movable seat (11); First layer excavation step, hardening and restoring the ground, excavating the first layer of soil of the foundation pit, constructing the corbel, erecting the horizontal support (72) inside the corbel, the horizontal support (72) is erected on the column (90), the column (90) bears the structural load of the constructed part, then the offset amount of each column pile is monitored, the horizontal offset amount is adjusted by the movable seat (11), the vertical offset amount is adjusted by pulling the anchor (52), and it is ensured that the settlement difference of each column (90) pile meets the standard; Second layer excavation step, excavating the second layer of soil of the foundation pit and constructing the second layer of horizontal support (72), which is also erected on the column (90) and bears the structural load of the constructed part, and the horizontal and vertical offset amounts are adjusted according to the method in the previous step; Bottom layer excavation step, the construction is cycled until the bottom of the foundation pit is excavated, the main bottom plate (73) is constructed as soon as possible, and then the main concrete structure is constructed upwards in turn, according to the calculation, when the gravity distributed to the column-pile and the pulling force of the anchor (52) are basically the same, it is indicated that the weight of the main structure is sufficient to balance the anchoring force of the anchor (52), at this time, the anchoring force of the anchor (52) is reduced, and permanent anchoring is performed at a set value; Permanent anchoring step, pouring the anchor (52) and the anchor device 5 into the main structure, and constructing the remaining structure according to the conventional method.

10. The topdown construction method according to claim 9, wherein In the casing group into hole step, when the casing group (92) is put in, the casing group (92) is covered with a sheath layer (922).

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