A construction method for DCM pile mixed foundation reinforcement in shallow mud geology

Abstract

The present invention relates to the foundation reinforcement of shoal mud geology, in particular to a construction method for DCM pile mixed foundation reinforcement for shoal mud geology, comprising the following steps: S1. driving steel pipe piles in water near the coast; S2. installing an operating platform system on a steel pipe pile group; S3. arranging a high-pressure rotary jet pile machine on the operating platform system, and using the high-pressure rotary jet pile machine (3) to construct high-pressure rotary jet piles; S4. constructing DCM piles on one side of the high-pressure rotary jet pile group to form a DCM pile group. The construction method for DCM pile mixed foundation reinforcement for shoal mud geology of the present application uses high-pressure rotary jet piles to replace DCM piles in areas with a large amount of miscellaneous fill stones in nearshore shoals, thereby solving the problem of soft foundation reinforcement under geological conditions containing miscellaneous fill stones, and avoiding the risk of slope collapse caused by excavating foundation trenches in nearshore shoal areas; constructing a high-pressure rotary jet pile group until the DCM ship pile machine can enter the water area for operation, and then constructing DCM piles in the water in the area to form a DCM pile group, so as to achieve the purpose of strengthening the foundation.

Description

Technical Field

[0001] The invention relates to foundation reinforcement of shallow mud geology, in particular to a construction method for DCM pile mixed foundation reinforcement of shallow mud geology. Background Art

[0002] At present, DCM piles are mainly used for foundation reinforcement of coastal embankments or land reclamation projects. DCM piles are constructed using large professional DCM ships. However, DCM ships have certain requirements for water depth (generally around 3.5m). In many cases, the shallow water in the shoal area near the coastline is shallow (generally 1.5m-2.5m) and there are also rocks, which cannot meet the water depth requirements. Summary of the invention

[0003] The purpose of the present invention is to provide a construction method for DCM pile mixed foundation reinforcement in shallow mud geology in order to solve the problem that DCM piles cannot be constructed in areas of nearshore shallows containing a large amount of miscellaneous fill stones in the prior art.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A construction method for DCM pile mixed foundation reinforcement for shallow mud geology, comprising the following steps:

[0006] S1. Driving a number of steel pipe piles in the water near the coast to form a steel pipe pile group;

[0007] S2. Installing a work platform system on the steel pipe pile group;

[0008] S3. A high-pressure rotary jet pile machine is provided on the operating platform system, and the high-pressure rotary jet pile machine is used to construct high-pressure rotary jet piles and form a high-pressure rotary jet pile group, wherein the high-pressure rotary jet pile machine can move on the operating platform system;

[0009] S4. Constructing DCM piles in the water on the sea side of the high-pressure jet grouting pile group to form a DCM pile group.

[0010] The present application discloses a construction method for DCM pile mixed foundation reinforcement for shallow mud geology. First, a ship or other means for constructing steel pipe piles in water working conditions of shallow mud geology is used to drive a number of steel pipe piles in water near the coast to form a steel pipe pile group. Then, based on the steel pipe pile group, an operating platform system is installed on the steel pipe pile group, and the operating platform system is used as a supporting foundation for a high-pressure rotary jet pile driver for constructing high-pressure rotary jet piles. Then, the high-pressure rotary jet pile driver is used to construct high-pressure rotary jet piles. The high-pressure rotary jet pile driver can move on the operating platform system to form a high-pressure rotary jet pile group, that is, in water near the coast, high-pressure rotary jet piles are used to replace DCM piles to achieve the purpose of reducing or avoiding dredging of underwater soil in the shallow area. The high-pressure rotary jet pile group is constructed until the DCM ship pile driver can enter the water area for operation, and then DCM piles are constructed in the water in this area to form a DCM pile group to achieve the purpose of strengthening the foundation.

[0011] The present application describes a construction method for DCM pile mixed foundation reinforcement for shallow mud geology, which first constructs a steel pipe pile group, and then uses a working platform system supported by the steel pipe pile group to construct a high-pressure rotary jet pile group. In areas near the shore shallows containing a large amount of miscellaneous fill stones, high-pressure rotary jet piles are used to replace DCM piles to solve the problem of soft foundation reinforcement under geological conditions containing miscellaneous fill stones, while avoiding the risk of slope collapse caused by excavating foundation trenches in near-shore shallow areas.

[0012] Preferably, a plurality of the steel pipe piles are arranged in an array, and the distance between adjacent steel pipe piles is greater than the distance between adjacent high-pressure jet-jet piles.

[0013] The present application describes a construction method for DCM pile mixed foundation reinforcement for shallow mud geology, in which a plurality of the steel pipe piles are arranged in an array, and the spacing between adjacent steel pipe piles is greater than the spacing between adjacent high-pressure rotary jet piles; the spacing between adjacent steel pipe piles is greater than the spacing between adjacent high-pressure rotary jet piles, and the arrangement of a plurality of the steel pipe piles can also perform preliminary reinforcement of the area close to the coast in the shallow area, and then carry out intensive reinforcement of the high-pressure rotary jet pile group, and the construction of the steel pipe piles can also form a transition for the reinforcement operation of the area close to the coast in the shallow area, so as to effectively reduce the lateral pressure effect of the intensive construction of high-pressure rotary jet piles on the coast.

[0014] Preferably, step S1 specifically includes:

[0015] S11. Arrangement of steel pipe pile positions: Arrange the steel pipe piles in the gaps within the high-pressure jet grouting pile group;

[0016] S12. Install a cover plate on the top of the steel pipe pile;

[0017] S13. Scissor braces are used to connect adjacent steel pipe piles in the same row longitudinally, and connecting beams are used to connect corresponding steel pipe piles in adjacent rows.

[0018] Preferably, step S2 specifically includes:

[0019] S21. Connecting the longitudinal main beam to the upper portion of the steel pipe piles in the same longitudinal column;

[0020] S22. Installing a track on the longitudinal main beam, the track is arranged along the length direction of the longitudinal main beam;

[0021] S23. Install an upper platform, wherein at least two of the rails support the upper platform, and the upper platform can move along the length direction of the rails, and all the rails that are slidably matched with the same upper platform are arranged in parallel.

[0022] Preferably, in S23, a pipe is installed on the upper platform, and the pipe is arranged horizontally;

[0023] In S3, the high-pressure rotary jet pile driver is installed on the pipe runner so that the high-pressure rotary jet pile driver can move laterally relative to the pipe runner.

[0024] Preferably, the construction method for DCM pile mixed foundation reinforcement for shallow mud geology described in the present invention further includes a DCM ship pile driver, the DCM ship pile driver includes a hull, a DCM drilling rig is arranged on the hull, the DCM drilling rig is provided with a DCM drill rod capable of vertical movement, and a stirring blade and a grouting port are arranged at the bottom of the DCM drill rod;

[0025] The shallow mud geology is a soft soil layer under the water, and there is a bearing layer under the soft soil layer;

[0026] In step S4, the DCM piles are constructed in water using a DCM ship pile driver, specifically:

[0027] S41.DCM drill pipe penetrates downward and the mixing blades enter the seabed;

[0028] S42. The DCM drill pipe is turned on and rotated. The mixing blades at the bottom of the DCM drill pipe rotate to cut the soil layer below the seabed until the bottom elevation of the DCM pile is reached. At this time, the bottom elevation of the DCM pile is located within the bearing layer.

[0029] S43. Using a mixing blade to mix the soil layer in the range of the first elevation to the bottom elevation of the DCM pile, the first elevation is located above the bottom elevation of the DCM pile. After the mixing is completed, the mixing blade is raised to the vicinity of the first elevation;

[0030] S44.DCM drill pipe is penetrated and grouting is sprayed at the grouting port until the DCM pile bottom elevation is reached;

[0031] S45. The DCM drill rod is pulled up and grouting is sprayed at the shotcrete port until the DCM pile top elevation is reached.

[0032] Preferably, the first elevation is T1, the elevation of the bottom of the DCM pile is T0, T1=T0+A, 5m≤A≤7m.

[0033] Preferably, the DCM pile group includes a plurality of DCM pile rows arranged at intervals, wherein the DCM pile rows are arranged in a transverse direction, and in each row of the DCM piles, two adjacent DCM piles are arranged at intervals, a first gap is provided between the two adjacent DCM piles, and the remaining adjacent DCM piles are engaged with each other, and the first gaps of adjacent DCM pile rows are staggered.

[0034] The first gap of the DCM pile row can not only ensure that the replacement rate of the soft foundation treatment is within an appropriate range, but also effectively reduce the structural internal stress of the interaction between the DCM piles in the DCM pile row.

[0035] Preferably, both ends of the DCM pile row are longitudinally provided with DCM pile groups, the DCM pile groups include a plurality of DCM piles arranged longitudinally, the adjacent DCM piles in the same DCM pile group are engaged with each other, and the DCM pile group is engaged with the corresponding ends of all DCM pile rows.

[0036] The DCM pile group is used to form all the DCM pile rows into a whole, so that the reinforcement and bearing effect of the DCM pile group is better. Under this scheme, the setting of the first gap can fully release the internal stress of the interaction between adjacent DCM piles in the DCM pile group without almost losing the reinforcement and bearing effect of the DCM pile group.

[0037] Preferably, the high-pressure jet grouting pile group comprises a plurality of spaced-apart rows of high-pressure jet grouting piles, the rows of high-pressure jet grouting piles are arranged in a transverse direction, and in each row of the high-pressure jet grouting piles, adjacent high-pressure jet grouting piles are engaged with each other;

[0038] A high-pressure rotary jet pile group is arranged between adjacent high-pressure rotary jet pile rows, the high-pressure rotary jet pile group is located at the end of the high-pressure rotary jet pile row, and the high-pressure rotary jet pile group includes at least two high-pressure rotary jet piles arranged in the longitudinal direction;

[0039] There is a second gap between adjacent rows of high-pressure jet-jet piles, and at least part of the steel pipe piles are located in the second gap.

[0040] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0041] 1. A construction method for DCM pile mixed foundation reinforcement for shallow mud geology described in this application, first use a ship or other means for constructing steel pipe piles in shallow mud geology water working conditions to drive a number of steel pipe piles in the water near the coast, and form a steel pipe pile group, then install an operating platform system on the steel pipe pile group based on the steel pipe pile group, and use the operating platform system as the support foundation of the high-pressure rotary jet pile machine for constructing high-pressure rotary jet piles, and then use the high-pressure rotary jet pile machine to construct high-pressure rotary jet piles, and the high-pressure rotary jet pile machine can move on the operating platform system to form a high-pressure rotary jet pile group, that is, in the water near the coast, high-pressure rotary jet piles are used to replace DCM piles, solve the problem of soft foundation reinforcement under the geological conditions of mixed filling stones, and avoid the risk of slope collapse caused by excavating foundation trenches in near-shore shallow areas. Construct a high-pressure rotary jet pile group until the DCM ship pile driver can enter the water area for operation, and then construct DCM piles in the water in this area to form a DCM pile group to achieve the purpose of strengthening the foundation. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 It is a schematic diagram of the construction process of a construction method of the present invention for DCM pile mixed foundation reinforcement in shallow mud geology.

[0043] Figure 2 It is a schematic diagram of the main view of the structure of the working platform supporting the high-pressure rotary jet pile machine of the present invention.

[0044] Figure 3 This invention is attached Figure 2 Enlarged schematic diagram of part A in the middle.

[0045] Figure 4 It is a top view schematic diagram of the structure of the working platform supporting the high-pressure rotary jet pile machine of the present invention.

[0046] Figure 5 It is a left side schematic diagram of the structure of a working platform supporting a high pressure rotary jet pile driver according to the present invention.

[0047] Figure 6 It is a schematic diagram of the arrangement of steel pipe piles of the present invention.

[0048] Figure 7 It is a schematic diagram of the connection between the steel pipe pile and the cover plate of the present invention.

[0049] Figure 8 It is a schematic diagram of the position of the longitudinal main beam of the present invention.

[0050] Fig. 9 It is a schematic diagram of the connection between the longitudinal main beam and the cover plate of the present invention.

[0051] Fig.10 It is a schematic diagram of the connection between the longitudinal main beam and the track of the present invention.

[0052] Fig.11 It is a schematic front view of the connection between the longitudinal main beam and the track of the present invention.

[0053] Fig.12 It is a schematic diagram of the upper platform structure of the present invention.

[0054] Fig.13 It is a schematic diagram of the layout of the working platform system and high-pressure jet grouting piles of the present invention (three spans).

[0055] Fig.14 It is a schematic diagram of the arrangement of the working platform system and high-pressure jet grouting piles (two spans) of the present invention.

[0056] Fig.15 It is a schematic diagram of the DCM construction process of the present invention.

[0057] Fig.16 It is a schematic diagram of the DCM construction model of the present invention.

[0058] Fig.17 It is a schematic diagram of the arrangement of the steel pipe piles, high-pressure rotary jet piles and DCM piles of the present invention (part of the steel pipe piles are located in the second gap).

[0059] Fig.18 This invention is attached Fig.17 Enlarged schematic diagram of part A in the middle.

[0060] Fig.19 This invention is attached Fig.17 Enlarged schematic diagram of part B in the middle.

[0061] Fig. 20 It is a schematic diagram of the arrangement of the steel pipe piles, high-pressure rotary jet piles and DCM piles of the present invention (all the steel pipe piles are located in the second gap).

[0062] Fig.21 It is a schematic diagram of the arrangement of the steel pipe piles, high-pressure rotary jet piles and DCM piles of the present invention (with a DCM pile group).

[0063] Icons: 1-steel pipe pile; 10-support truss; 11-pile-driving ship; 12-cover plate; 13-steel rib plate; 14-longitudinal main beam; 15-scissor brace; 16-angle iron; 17-upper platform; 18-track wheel group; 19-connecting beam; 2-working platform system; 21-telescopic device; 3-high-pressure rotary jet pile driver; 31-frame; 32-drill rod; 33-pipeline; 34-tower; 36-drill bit; 37-traveling device; 4-high-pressure rotary jet pile; 41-high-pressure rotary jet pile row; 42-high-pressure rotary jet pile group; 43-second gap; 5-track; 51-track presser; 6-DCM pile; 61-DCM drill rod; 62-mixing blade; 64-DCM pile row; 65-DCM pile group; 66-first gap. DETAILED DESCRIPTION

[0064] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0065] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0066] Example 1

[0067] like Figure 1-21 As shown, a construction method for DCM pile mixed foundation reinforcement for shallow mud geology includes the following steps:

[0068] S1. Driving a number of steel pipe piles 1 in the water near the coast to form a steel pipe pile group;

[0069] S2. Installing the work platform system 2 on the steel pipe pile group;

[0070] S3. A high-pressure rotary jet pile machine 3 is provided on the working platform system 2, and the high-pressure rotary jet pile machine 3 is used to construct high-pressure rotary jet piles 4, and a high-pressure rotary jet pile group is formed, wherein the high-pressure rotary jet pile machine 3 can be moved on the working platform system 2;

[0071] S4. Constructing DCM piles 6 in the water on the sea side of the high-pressure jet grouting pile group to form a DCM pile group.

[0072] The present application discloses a construction method for DCM pile mixed foundation reinforcement for shallow mud geology, which first uses a ship or other means for constructing steel pipe piles in water working conditions of shallow mud geology to drive a number of steel pipe piles 1 in the water near the coast to form a steel pipe pile group, and then installs an operating platform system 2 on the steel pipe pile group based on the steel pipe pile group, and uses the operating platform system 2 as a support foundation for a high-pressure rotary jet pile machine 3 for constructing high-pressure rotary jet piles 4, and then uses the high-pressure rotary jet pile machine 3 to construct the high-pressure rotary jet piles 4. The jet grouting pile driver 3 can move on the working platform system 2 and form a high-pressure jet grouting pile group, that is, in the water near the coast, the high-pressure jet grouting pile 4 is used to replace the DCM pile 6 to achieve the purpose of reducing or avoiding the dredging work of the underwater soil in the shallow area. The high-pressure jet grouting pile group is constructed until the DCM ship pile driver can enter the water area for operation, or the dredging cost is less than the cost of installing the steel pipe pile group and the working platform system 2 in the water area, and then the DCM pile 6 is constructed in the water in the area to form a DCM pile group to achieve the purpose of strengthening the foundation.

[0073] In a general construction process, a plurality of the steel pipe piles 1 are arranged in an array, and the distance between adjacent steel pipe piles 1 is greater than the distance between adjacent high-pressure rotary jet piles 4 .

[0074] The present application describes a construction method for DCM pile mixed foundation reinforcement for shallow mud geology, wherein a plurality of the steel pipe piles 1 are arranged in an array, and the spacing between adjacent steel pipe piles 1 is greater than the spacing between adjacent high-pressure rotary jet piles 4; the spacing between adjacent steel pipe piles 1 is greater than the spacing between adjacent high-pressure rotary jet piles 4. The arrangement of the plurality of steel pipe piles 1 can also perform preliminary reinforcement of the area close to the coast in the shallow area, and then perform intensive reinforcement of the high-pressure rotary jet pile group. The construction of the steel pipe piles 1 can also form a transition for the reinforcement operation of the area close to the coast in the shallow area, so as to effectively reduce the lateral pressure effect of the intensive construction of the high-pressure rotary jet piles 4 on the coast.

[0075] Step S1 is specifically as follows:

[0076] S11. Arrangement of steel pipe pile 1: Arrange steel pipe pile 1 in the gap position within the high-pressure jet grouting pile group;

[0077] S12. Install the cover plate 12 on the top of the steel pipe pile 1;

[0078] S13. The adjacent steel pipe piles 1 in the same row are connected with scissor braces 15 , and the corresponding steel pipe piles 1 in adjacent rows are connected with connecting beams 19 .

[0079] Specifically, the connecting beam 19 is a rectangular tube or a circular tube.

[0080] Specifically, the working platform system 2 includes an upper platform 17 and a longitudinal main beam 14 connected to the upper part of the steel pipe piles 1 in the same longitudinal row. A supporting truss 10 is arranged at the bottom of the upper platform 17. A track 5 is installed on the longitudinal main beam 14. The track 5 is arranged along the length direction of the longitudinal main beam 14. A track wheel group 18 is arranged on the supporting truss 10. The track wheel group 18 rolls with the corresponding track 5.

[0081] Specifically, the rail wheel group 18 is connected to the lower part of the support truss 10, and the support truss 10 is provided with a first support 22 and a second support 23, and the first support 22 and the second support 23 are both detachably connected to the upper platform 17, and a telescopic device 21 is hinged on the second support 23, one end of the telescopic device 21 is hinged to the second support 23, and the other end of the telescopic device 21 is hinged to the support truss 10, and the telescopic device 21 can drive the second support 23 to move along the support truss 10 horizontally relative to the support truss The frame 10 is moved. Since both the upper platform 17 and the supporting truss 10 have relatively large structures, during installation, the first support 22 and the second support 23 are detachably connected to the upper platform 17 to realize the detachable connection between the upper platform 17 and the supporting truss 10, so that the upper platform 17 and the supporting truss 10 can be transported separately and prefabricated in a factory. In this case, the telescopic device 21 is used to fine-tune the lateral position of the second support 23 along the supporting truss 10, thereby speeding up the on-site installation difficulty of the upper platform 17 and the supporting truss 10.

[0082] Step S2 is specifically as follows:

[0083] S21. In the longitudinal direction, the upper portion of the steel pipe pile 1 in the same column is connected to the longitudinal main beam 14;

[0084] S22. The track 5 is installed on the longitudinal main beam 14, and the track 5 is arranged along the length direction of the longitudinal main beam 14;

[0085] S23. Install the upper platform 17, at least two of the rails 5 support the upper platform 17, and the upper platform 17 can move along the length direction of the rails 5, and all the rails 5 that are slidably matched with the same upper platform 17 are arranged in parallel.

[0086] In the above S23, the pipe 33 is installed on the upper platform 17, and the pipe 33 is arranged horizontally;

[0087] In S3 , the high-pressure rotary jet pile driver 3 is installed on the pipe runner 33 , and a traveling device 37 is provided at the bottom of the high-pressure rotary jet pile driver 3 , so that the high-pressure rotary jet pile driver 3 can move laterally relative to the pipe runner 33 through the traveling device 37 .

[0088] The walking device 37 is a walking wheel, and the walking wheel and the walking pipe 33 are rollingly matched.

[0089] On the basis of the above, in a further preferred embodiment, the construction method for DCM pile mixed foundation reinforcement for shallow mud geology described in the present invention further includes a DCM ship pile driver, the DCM ship pile driver includes a hull, a DCM drilling rig is arranged on the hull, the DCM drilling rig is provided with a DCM drill rod 61 capable of vertical movement, a stirring blade 62, a water liquid spray head and a spraying port are arranged at the bottom of the DCM drill rod 61, and the water liquid spray head is used to spray water to the stirring blade 62;

[0090] The shallow mud geology is a soft soil layer under the water, and there is a bearing layer under the soft soil layer;

[0091] In step S4, the DCM pile 6 is constructed in water using a DCM ship pile driver, specifically:

[0092] S41. The DCM drill pipe 61 is penetrated downward, and the mixing blade 62 enters the seabed;

[0093] S42. The DCM drill pipe 61 is turned on and rotated. The mixing blade 62 at the bottom of the DCM drill pipe 61 rotates to cut the lower soil layer of the seabed until the bottom elevation of the DCM pile 6. At this time, the bottom elevation of the DCM pile 6 is located within the bearing layer;

[0094] S43. Use the mixing blade 62 to mix the soil layer from the first elevation to the bottom elevation of the DCM pile 6, the first elevation is located above the bottom elevation of the DCM pile 6, the first elevation is T1, the bottom elevation of the DCM pile 6 is T0, T1 = T0 + A, 5m ≤ A ≤ 7m, after the mixing is completed, the mixing blade 62 is raised to the vicinity of the first elevation;

[0095] S44. The DCM drill rod 61 is penetrated downward, and the grouting port is sprayed until the bottom elevation of the DCM pile 6 is reached;

[0096] S45. The DCM drill rod 61 is pulled up, and the grouting port is sprayed until the top elevation of the DCM pile 6 is reached.

[0097] like Figure 19-20 As shown, on the basis of the above, in a further preferred manner, the DCM pile group includes a plurality of DCM pile rows 64 arranged at intervals, and the DCM pile rows 64 are arranged in the transverse direction. In each row of the DCM pile rows 64, two adjacent DCM piles 6 are arranged at intervals, and a first gap 66 is provided between the two adjacent DCM piles 6. The remaining adjacent DCM piles 6 are engaged with each other, and the first gaps 66 of adjacent DCM pile rows 64 are staggered to ensure the overall stability of the DCM pile group.

[0098] The first gap 66 of the DCM pile row 64 can ensure that the soft foundation treatment replacement rate is within an appropriate range, and can effectively reduce the structural internal stress of the interaction between the DCM piles 6 in the DCM pile row 64.

[0099] like Fig.21 As shown, on the basis of the above, in a further preferred manner, both ends of the DCM pile row 64 are longitudinally provided with DCM pile groups 65, the DCM pile groups 65 include a plurality of DCM piles 6 arranged longitudinally, the adjacent DCM piles 6 in the same DCM pile group 65 are engaged with each other, and the DCM pile group 65 is engaged with the corresponding ends of all DCM pile rows 64.

[0100] The DCM pile group 65 is used to form all the DCM pile rows 64 into a whole, so that the reinforcement and bearing effect of the DCM pile group is better. Under this scheme, the setting of the first gap 66 is particularly important. It can fully release the internal stress of the interaction between adjacent DCM piles 6 in the DCM pile group without almost losing the reinforcement and bearing effect of the DCM pile group.

[0101] like Figure 19-21 As shown, on the basis of the above, in a further preferred manner, the high-pressure rotary jet pile group includes a plurality of high-pressure rotary jet pile rows 41 arranged at intervals, the high-pressure rotary jet pile rows 41 are arranged in the transverse direction, and in each row of the high-pressure rotary jet pile rows 41, the adjacent high-pressure rotary jet piles 4 are engaged with each other;

[0102] A high-pressure jet grouting pile group 42 is provided between adjacent high-pressure jet grouting pile rows 41. The high-pressure jet grouting pile group 42 is located at the end of the high-pressure jet grouting pile row 41. The high-pressure jet grouting pile group 42 includes at least two high-pressure jet grouting piles 4 arranged in the longitudinal direction.

[0103] There is a second gap 43 between adjacent rows of high-pressure jet-jet piles 41 , and at least part of the steel pipe piles 1 is located in the second gap 43 .

[0104] Beneficial effects of this embodiment: The construction method for DCM pile mixed foundation reinforcement in shallow mud geology described in this embodiment first constructs a steel pipe pile group, and then uses a working platform system supported by the steel pipe pile group to construct a high-pressure rotary jet pile group. In areas near the shore containing a large amount of miscellaneous fill stones, high-pressure rotary jet piles are used to replace DCM piles to solve the problem of soft foundation reinforcement under geological conditions containing miscellaneous fill stones, while avoiding the risk of slope collapse caused by excavating foundation trenches in near-shore shallow areas.

[0105] Example 2

[0106] like Figure 1-21 As shown, the construction method of DCM pile mixed foundation reinforcement for shallow mud geology described in this embodiment, based on Example 1, specifically introduces the construction process of steel pipe pile group, working platform system 2 and high-pressure rotary jet pile 4:

[0107] In this embodiment, steel pipe piles 1 are driven offshore and an operating platform system 2 is set up offshore to provide an operating platform system 2 for the construction of high-pressure jet grouting piles 4. The construction process of the operating platform system 2 is detailed in Figure 1 :

[0108] like Figure 2-14 As shown, the construction of the working platform system 2 first constructs the steel pipe pile group, then installs the working platform system 2, and finally installs the high-pressure rotary jet pile machine 3. The specific construction steps are as follows:

[0109] 1 Construction of steel pipe pile group: measurement and positioning → driving steel pipe pile 1 → installing pile top cover 12 → installing scissor brace 15;

[0110] 2 Installing platform 2 system: installing longitudinal main beam 14 → installing track 5 → installing upper platform 17;

[0111] 3 Install the pile driver system: install the pipe 33 → install the high-pressure rotary jet pile driver 3 → install the slurry supply system.

[0112] A movable working platform system 2 is arranged on the upper part, and its lower part is supported by a plurality of steel pipe piles 1 and scissor struts 15. The upper working platform system 2 can drive the high-pressure rotary jet pile driver 3 to move left and right, front and back, and the high-pressure rotary jet pile driver 3 is supported and arranged on the working platform system 2.

[0113] Backstage slurry supply system: The backstage slurry supply system is used to supply slurry to the high-pressure rotary jet pile driver 3. Considering the shore setting, the slurry supply range is large. Each set of backstage slurry supply system includes 2 slurry making machines, 2 slurry storage tanks, 4 80t horizontal cement tanks and 4 grouting pumps.

[0114] Steel pipe pile group construction:

[0115] 1. Arrangement of steel pipe piles 1: The steel pipe piles 1 are arranged in the gaps between the high pressure jet grouting piles 4 according to the design drawings so as not to affect the construction of the high pressure jet grouting piles 4 and ensure that all the high pressure jet grouting piles 4 within the scope of the working platform system 2 can be constructed. Multiple steel pipe piles 1 are arranged in an array.

[0116] The diameter of the steel pipe pile 1 is Φ500mm~Φ750mm, and the pile length is determined according to the geological survey data. Generally, the pile length is 16~22m. The lower end of the steel pipe pile 1 abuts against or extends into the bearing layer, and the bearing layer is made of fully weathered rock.

[0117] 2. Measurement and positioning: The steel pipe piles 1 are driven by a pile-driving ship 11, which performs measurement and positioning by GPS. The pile-driving ship 11 has a shallow draft and can meet the requirements for water operations in shallow areas.

[0118] 3. Driving the steel pipe pile 1: Use the pile driving ship 11 to carry out the steel pipe pile 1 sinking construction. After the construction of the steel pipe pile 1 is completed, use an infrared level to measure the elevation of the top of the steel pipe pile 1, and use oxygen welding to cut off and level the part that exceeds the height.

[0119] 4. Install the cover plate 12: Install the cover plate 12 on the top of the steel pipe pile 1. The four corners of the cover plate 12 are connected and fixed to the steel pipe pile 1 by using triangular steel ribs 13.

[0120] 5. Install the scissor brace 15: connect the scissor brace 15 between the adjacent steel pipe piles 1 in the same row in the longitudinal direction to complete the installation construction of the steel pipe pile group.

[0121] 6. Installation of the longitudinal main beam 14: The longitudinal main beam 14 is made of rectangular steel. Before installing the longitudinal main beam 14, use an infrared level to measure the position and mark it on the cover plate 12 to ensure that the positioning deviation of the longitudinal main beam 14 meets the requirements. The longitudinal main beam 14 and the cover plate 12 are welded firmly with angle irons 16. The middle of the scissor brace 15 is vertically connected with a vertical rod, and the top of the vertical rod is connected to the corresponding longitudinal main beam 14 to increase the support stiffness of the longitudinal main beam 14.

[0122] 7. Install the track 5: Install the track 5 on the longitudinal main beam 14 , and the track 5 is arranged along the length direction of the longitudinal main beam 14 .

[0123] The track 5 can be a common steel rail, and the track 5 is locked with the longitudinal main beam 14 by a rail clamp 51. At the same time, a circular hole of Φ100mm-Φ150mm needs to be opened on one side of the longitudinal main beam 14 to facilitate the installation and fastening of the bolts connecting the rail clamp 51 and the longitudinal main beam 14.

[0124] After the track 5 is installed and before the track clamp 51 is locked, the track 5 is measured and positioned using an infrared level to ensure that the track gauges on both sides of a span are consistent with the track wheel set 18 of the upper platform 17. If the deviation is large, it is adjusted in time, and finally the track clamp 51 is locked.

[0125] 8. Install the upper platform 17: The upper platform 17 is mainly used for the load bearing and displacement of the high pressure rotary grouting pile machine 3. Fig.12 As shown. It can be processed in a workshop and assembled on site, wherein at least four track wheel sets 18 are arranged at the bottom of the upper platform 17, each track wheel set 18 is provided with at least one track wheel, and at least four track wheel sets 18 form two rows, which are rolled with the corresponding tracks 5 to achieve the purpose of moving the upper platform 17 on the track 5. A motor is arranged on the upper platform 17, and the motor drives at least one track wheel set 18 to rotate, so as to provide power for the upper platform 17 to move on the track 5.

[0126] Install the high-pressure rotary jet pile machine 3: The high-pressure rotary jet pile machine 3 adopts a conventional high-pressure rotary jet pile machine 3, which includes a frame 31, a tower 34 and a drilling rig. The drilling rig includes a drill rod 32 and a drill bit 36 ​​connected to the bottom of the drill rod 32. Each high-pressure rotary jet pile machine 3 is equipped with a two-axis drill rod 32, that is, each pile machine simultaneously constructs two high-pressure rotary jet piles 4. The height of the frame 31 is comprehensively considered according to the design length of the high-pressure rotary jet pile 4. The length of the high-pressure rotary jet pile 4 is comprehensively considered based on the height of the platform 2 itself and the water depth, etc., and the height of the tower 34 is generally not more than 18 meters. The longitudinal displacement is controlled by the working platform system 2, and the lateral displacement adopts the pipe 33 type displacement. The pipe 33 is fixed on the upper platform 17. Angle irons are welded on both ends of the pipe 33 as limit blocks to ensure that the high-pressure rotary jet pile 4 will not be separated from the pipe 33 when it moves horizontally. When the pile mixing machine is shifted, the tower frame 34 must be adjusted to tilt backward by about 3 to 4 degrees to ensure that the center of gravity of the tower frame 34 is located within the cross beam of the upper platform 17.

[0127] like Figure 15-16 As shown, the construction process of high-pressure jet grouting pile 4 is as follows:

[0128] 1. Technical briefing: According to the design requirements and relevant specifications, carry out technical briefing work on the design drawings and make preparations before construction.

[0129] 2. Positioning of high-pressure jet grouting pile 4: Before construction, use a total station to determine the control points of the high-pressure jet grouting pile 4 construction, and mark them on the working platform system 2. Ensure that the displacement deviation of the center of the high-pressure jet grouting pile 4 is within the specified range.

[0130] 3. Drilling hole: Use down-the-hole hammer to crush the riprap and drill the drilling hole, the drilling depth is 2.3-2.7m.

[0131] 4. Drilling rig in place: A drilling rig is provided on the high-pressure rotary jet pile machine 3. After the drilling rig is in place, the high-pressure rotary jet pile machine 3 is leveled and centered, and the verticality of the high-pressure rotary jet pile machine 3 is adjusted to ensure that the drill rod 32 is consistent with the pile position; the air compressor and mud pump should be debugged before drilling to ensure that the equipment operates normally; the length of the drill rod 32 is checked, and the depth line is marked next to the drilling tower with red paint to ensure that the bottom elevation of the hole meets the designed depth.

[0132] 5. Drilling: After the drilling rig is in place, the drill bit 36 ​​is aligned with the center of the high-pressure rotary jet pile 4. The drilling rig is corrected with a level ruler to make the drill rod 32 vertical, and then the drilling rig is placed to prevent the drilling rig from shifting and deviating from the center of the high-pressure rotary jet pile 4. The diameter and depth of the hole made by the drilling rig are in accordance with the design requirements. After the drilling rig is completed, it is shifted, and the high-pressure rotary jet pile driver 3 is in place, so that the three points of the drilling rig rotation center, the drill rod center and the high-pressure rotary jet pile 4 center are in a straight line, and the drilling rig is leveled.

[0133] 6. Jet-jet lifting: When the jet grouting pipe on the high-pressure jet-jet pile machine 3 is inserted into the designed depth, turn on the high-pressure grouting pump and air compressor, connect the mud pump, and then jet from bottom to top, while cleaning and discharging the mud. When jetting, the predetermined jet pressure should be reached first, and then the jet-jet pipe should be gradually lifted after grouting to prevent the jet-jet pipe from being twisted off. In order to ensure the quality of the bottom end of the pile, when the nozzle sinks to the designed depth, it should rotate at the original position for about 10 seconds, and then jet-jet lift after the slurry is normally emitted from the orifice. The rotation and lifting of the drill rod 32 should be carried out continuously and should not be interrupted. If the drilling rig fails, the lifting and rotation of the drill rod 32 should be stopped to prevent the pile from breaking, and the fault should be repaired and eliminated immediately. In order to improve the quality of the bottom end of the pile, the jet-jet time of the drill rod 32 should be appropriately increased within 1.0m of the bottom of the pile. During the jet-jet lifting process, the jet-jet parameters can be adjusted according to different soil layers.

[0134] 7. Cleaning and relocation: After the grouting pile is completed, the drill rod 32 is pulled out, and the slurry pump, the drill rod 32 and the slurry delivery pipeline are cleaned with clean water, and then the slurry pump, the drill rod 32 and the slurry delivery pipeline are relocated to carry out the construction of the next high-pressure rotary jet pile 4.

[0135] After the installation of the working platform system 2 is completed, it is debugged first to ensure normal operation. The high-pressure rotary jet pile machine 3 is moved to the pile position to start the construction of the high-pressure rotary jet pile 4. During the construction of the high-pressure rotary jet pile 4, one high-pressure rotary jet pile machine 3 can be arranged for each span. At this time, the high-pressure rotary jet pile machines 3 in adjacent spans can share the track 5. Figure 3 As shown, multiple high-pressure rotary jet pile machines 3 can also be arranged.

[0136] Example 3

[0137] like Figure 1-21 As shown, the construction method of DCM pile mixed foundation reinforcement for shallow mud geology described in this embodiment is based on Example 1, and the difference from Example 2 is that: the construction method and process technology scheme of DCM pile 6 are specifically introduced:

[0138] The specific construction flow chart of DCM pile 6 is as follows Fig.15 and 16 shown.

[0139] DCM ship pile driver, the DCM ship pile driver includes a hull, a DCM drilling rig is arranged on the hull, the DCM drilling rig is provided with a DCM drill rod 61 that can move vertically, the bottom of the DCM drill rod 61 is provided with a stirring blade 62, a water liquid spray head and a spraying port, the water liquid spray head is used to spray water to the stirring blade 62, the spraying port includes a lower spraying port and a central spraying port, the lower spraying port is located at the lower part of the stirring blade 62, and the central spraying port is located at the upper part of the stirring blade 62.

[0140] 1. Cutting soil and penetrating downward: The DCM drill pipe 61 penetrates downward and the mixing blades 62 enter the seabed.

[0141] After the mixing blade 62 enters the seabed, the DCM drill pipe 61 is turned on and the mixing blade 62 at the bottom of the DCM drill pipe 61 rotates to cut the soil layer, reducing the strength of the soil layer, and using the deadweight of the DCM drill pipe 61 to drill down. When the DCM processor mixing blade 62 penetrates into the bearing layer, adjust the penetration speed and water spraying volume: the penetration speed is reduced from 0.8-1.2m / s to 0.3-0.5m / s, and the water spraying volume is increased to 300-350m 3 / min.

[0142] 2. Spraying piles: Since the lower spraying port is located at the lower part of the mixing blade 62 and the central spraying port is located at the upper part of the mixing blade 62, in order to ensure the continuity of the spraying and the number of mixing times, for long piles, the lower part of the mixing body is sprayed downward using the lower spraying port, and the upper part of the mixing body is sprayed upward using the central spraying port; for short piles, the entire pile body is sprayed downward using the lower spraying port.

[0143] a. Before the DCM drill pipe 61 is pulled up to the designed position, it is necessary to spray in advance to squeeze out the water in the spray pipeline to ensure the stability of the cement slurry during the process of drilling down.

[0144] b. After the DCM pile 6 bottom reinforcement shotcrete is completed, there is a lot of mud in the shotcrete pipeline and the lower shotcrete port. In the subsequent stage, the central shotcrete port is used to pull up the shotcrete, and the lower shotcrete port is easy to be blocked. When the lower shotcrete is about to reach the bottom of DCM pile 6, start the bottom water spray to squeeze the slurry in the shotcrete pipeline to the bottom of the pile and clean the lower shotcrete port. In order to ensure the quality of the pile bottom, the shotcrete can be pulled up and down 1m at this stage to increase the number of stirring times at the bottom.

[0145] c. Upper pull-up grouting: Upper pull-up grouting adopts central grouting port grouting. At this time, there is a lot of water in the grouting pipeline, and it is necessary to start grout squeezing in advance to ensure that the grouting amount reaching the designed position at the bottom of the pile is stable. When the upper pull-up grouting reaches 5m below the pile top, the rotation speed and upper pull-up speed of the DCM drill rod 61 need to be reduced to avoid excessive disturbance of the mixing blade 62 on the pile top, which may cause cement slurry loss and ensure the quality of the pile head.

[0146] d. Moving the ship: After the construction of the DCM piles 6 is completed, the ship is moved to the next set of pile positions to carry out the construction of the next set of DCM piles 6.

[0147] exist Fig.16 In the construction, Figure a shows the equipment placement construction, Figure b shows the soil penetration construction, Figure c shows the continuous penetration construction, Figure d shows the penetration to the pile bottom elevation construction, Figure e shows the pulling up construction from the pile bottom elevation, Figure f shows the reverse mixing construction, Figure g shows the pile bottom reinforcement construction, and Figure h shows the pulling up and continuous grouting construction.

[0148] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A construction method for DCM pile mixed foundation reinforcement in shallow mud geology, characterized in that: The following steps are involved: S1. Driving a number of steel pipe piles (1) in the water near the coast to form a steel pipe pile group; S2. Installing a work platform system (2) on the steel pipe pile group; S3. A high-pressure rotary jet pile machine (3) is arranged on the working platform system (2), and the high-pressure rotary jet pile machine (3) is used to construct high-pressure rotary jet piles (4) to form a high-pressure rotary jet pile group, wherein the high-pressure rotary jet pile machine (3) is movable on the working platform system (2); S4. Construction of DCM piles (6) in the water on the sea side of the high-pressure jet grouting pile group to form a DCM pile group; The DCM pile group comprises a plurality of DCM pile rows (64) arranged at intervals, wherein the DCM pile rows (64) are arranged in a transverse direction, and in each row of the DCM pile rows (64), two adjacent DCM piles (6) are arranged at intervals, a first gap (66) is provided between the two adjacent DCM piles (6), and the remaining adjacent DCM piles (6) are engaged with each other, and the first gaps (66) of adjacent DCM pile rows (64) are staggered; Both ends of the DCM pile row (64) are provided with DCM pile groups (65) along the longitudinal direction. The DCM pile group (65) includes a plurality of DCM piles (6) arranged along the longitudinal direction. Adjacent DCM piles (6) in the same DCM pile group (65) are engaged with each other. The DCM pile group (65) is engaged with corresponding ends of all DCM pile rows (64), and all DCM pile rows (64) are formed into a whole by using the DCM pile group (65).

2. A construction method for DCM pile mixed foundation reinforcement for shallow mud geology according to claim 1, characterized in that: The plurality of steel pipe piles (1) are arranged in an array, and the spacing between adjacent steel pipe piles (1) is greater than the spacing between adjacent high-pressure jet grouting piles (4).

3. A construction method for DCM pile mixed foundation reinforcement for shallow mud geology according to claim 2, characterized in that: Step S1 is specifically as follows: S11. Steel pipe pile (1) pile position arrangement: The steel pipe pile (1) is arranged in the gap position within the high-pressure jet grouting pile group; S12. Installing a cover plate (12) on the top of the steel pipe pile (1); S13. Connect the scissor braces (15) between adjacent steel pipe piles (1) in the same longitudinal row, and the corresponding steel pipe piles (1) in adjacent rows A connecting beam (19) is connected therebetween.

4. A construction method for DCM pile mixed foundation reinforcement for shallow mud geology according to claim 3, characterized in that: Step S2 is specifically as follows: S21. Connecting the longitudinal main beam (14) to the upper portion of the steel pipe piles (1) in the same longitudinal row; S22. Installing a track (5) on the longitudinal main beam (14), wherein the track (5) is arranged along the length direction of the longitudinal main beam (14); S23. Install an upper platform (17), wherein at least two of the rails (5) support the upper platform (17), and the upper platform (17) is movable along the length direction of the rails (5), and is arranged in parallel with all the rails (5) that are slidably matched with the same upper platform (17).

5. The construction method of DCM pile mixed foundation reinforcement for shallow mud geology according to claim 4 is characterized in that: In S23, a pipe guide (33) is installed on the upper platform (17), and the pipe guide (33) is arranged horizontally; In S3, the high-pressure rotary jet pile machine (3) is installed on the pipe (33) so that the high-pressure rotary jet pile machine (3) can move laterally relative to the pipe (33).

6. The construction method of DCM pile mixed foundation reinforcement for shallow mud geology according to claim 1 is characterized in that: Also included is a DCM ship pile driver, the DCM ship pile driver comprising a hull, a DCM drilling rig being arranged on the hull, the DCM drilling rig being provided with a DCM drill rod (61) capable of vertical movement, and a stirring blade (62) and a grouting port being arranged at the bottom of the DCM drill rod (61); The shallow mud geology is a soft soil layer under the water, and there is a bearing layer under the soft soil layer; In step S4, a DCM pile (6) is constructed in water using a DCM ship pile driver, specifically: S41. The DCM drill pipe (61) is penetrated downward, and the mixing blade (62) enters the seabed; S42. The DCM drill rod (61) is turned on and the stirring blade (62) at the bottom of the DCM drill rod (61) is turned on. Rotating and cutting the soil layer below the seabed until the bottom elevation of the DCM pile (6), at which point the bottom elevation of the DCM pile (6) is located within the bearing layer; S43. Using a mixing blade (62), a soil layer in a range from a first elevation to a bottom elevation of a DCM pile (6) is mixed, wherein the first elevation is located above the bottom elevation of the DCM pile (6). After the mixing is completed, the mixing blade (62) is raised to the vicinity of the first elevation; S44. The DCM drill rod (61) is penetrated downward, and grouting is sprayed at the grouting port until the bottom elevation of the DCM pile (6) is reached; S45. The DCM drill rod (61) is pulled upward and grouting is sprayed from the grouting port until the top elevation of the DCM pile (6) is reached.

7. The construction method of DCM pile mixed foundation reinforcement for shallow mud geology according to claim 6 is characterized in that: The first elevation is T1, the elevation of the bottom of the DCM pile (6) is T0, T1=T0+A, 5m≤A≤7m.

8. A construction method for DCM pile mixed foundation reinforcement for shallow mud geology according to any one of claims 1 to 7, characterized in that: The high-pressure jet grouting pile group comprises a plurality of high-pressure jet grouting pile rows (41) arranged at intervals, the high-pressure jet grouting pile rows (41) being arranged in a transverse direction, and in each row of the high-pressure jet grouting pile rows (41), adjacent high-pressure jet grouting piles (4) are engaged with each other; A high-pressure jet grouting pile group (42) is arranged between adjacent high-pressure jet grouting pile rows (41), the high-pressure jet grouting pile group (42) is located at the end of the high-pressure jet grouting pile row (41), and the high-pressure jet grouting pile group (42) includes at least two high-pressure jet grouting piles (4) arranged in the longitudinal direction; A second gap (43) is provided between adjacent rows of high-pressure jet-jet piles (41), and at least a portion of the steel pipe piles (1) is located in the second gap (43).

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