A construction method for supporting foundation pit with pipe piles while drilling

Abstract

The present application discloses a method for construction of foundation pit support with pipe piles while drilling, which relates to the technical field of foundation pit support, and includes the following steps: using pile sinking construction equipment to carry out prefabricated pipe pile sinking construction, so as to realize the spacing arrangement of multiple prefabricated pipe piles, wherein the prefabricated pipe pile is provided with a pipe pile inner hole penetrating the prefabricated pipe pile along its own axial direction, and a grouting hole penetrating the prefabricated pipe pile is provided on the hole wall of the pipe pile inner hole; using grouting equipment to inject solidified water sealing material into the gap between the prefabricated pipe piles through the grouting hole. It avoids the problems of high cost and long cycle of reinforcement treatment by using mixing piles, etc., which is conducive to reducing the construction cost of foundation pit support and giving full play to the advantage of short cycle of using prefabricated pipe piles for foundation pit support.

Description

Technical Field

[0001] The present application relates to the technical field of foundation pit support, and in particular to a construction method of foundation pit support using piles while drilling. Background Art

[0002] During the development and construction of urban underground space, the foundation pit support structure can support, reinforce and protect the side wall soil in the affected area around the excavation area, thereby ensuring normal construction operations in the foundation pit and the safety of the surrounding environment.

[0003] Traditional foundation pit support structures mostly use soil nail walls, mixing piles, reinforced concrete sheet piles, bored piles, retaining walls and underground continuous walls. When using the above support technologies, there are problems such as multiple support construction procedures, long construction period and high cost.

[0004] The construction technology of drilling and pipe pile can realize the efficient pile sinking construction of prefabricated pipe piles, so the method of using prefabricated pipe piles for foundation pit support has been gradually applied. Engineering applications show that when using the drilling and pipe pile technology for foundation pit support, on the one hand, prefabricated pipe piles do not need maintenance, which is conducive to shortening the construction period; on the other hand, the drilling and pipe pile technology is carried out simultaneously for drilling-soil discharge-pile sinking, without soil squeezing effect, and the prefabricated pipe piles protect the wall during the drilling process, and have good stratum adaptability, especially in complex broken strata and strata with serious leakage. In addition, the construction residue of drilling and pipe pile can be backfilled with prefabricated pipe piles, and there is no mud and drainage during the construction process, which is environmentally friendly.

[0005] However, in order to ensure smooth pile sinking, the diameter of the drill hole is slightly larger than the diameter of the pipe pile during the construction of the support piles. Therefore, there is a certain gap between adjacent prefabricated pipe piles after construction. In most construction sites, there is no need to deal with the gap. However, in construction sites with loose and broken strata and groundwater levels higher than the bottom of the foundation pit, it is necessary to construct mixing piles between two prefabricated pipe piles for support and water stopping of the gap between the pipe piles. Supporting and water stopping the gap between the pipe piles will make the advantages of the use of drilling and pipe pile construction, such as a short construction period, less obvious. Summary of the invention

[0006] In view of this, the purpose of this application is to provide a method for construction of pile foundation pit support while drilling, which does not require additional personnel for on-site verification, reduces workload, improves efficiency, and realizes efficient intelligent supervision.

[0007] In order to achieve the above technical purpose, the present application provides a method for construction of foundation pit support with pipe piles while drilling, comprising the steps of:

[0008] The prefabricated pipe piles are constructed by using pile sinking equipment to achieve the spacing of multiple prefabricated pipe piles, wherein the prefabricated pipe piles are provided with a pipe pile inner hole penetrating the prefabricated pipe piles along their own axial direction, and a grouting hole penetrating the prefabricated pipe piles is provided on the hole wall of the pipe pile inner hole;

[0009] Grouting equipment is used to inject solidified water-sealing material into the gaps between the prefabricated pipe piles through the grouting holes.

[0010] Furthermore, there are at least two grouting holes, at least one of which is arranged toward the soil facing side to form a soil facing side grouting hole, and at least one of which is arranged toward the adjacent prefabricated pipe piles to form a pipe pile gap grouting hole.

[0011] Furthermore, before injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles through the grouting holes using the grouting equipment, the method further includes the following steps:

[0012] The prefabricated pipe piles are sequentially fastened together by first fasteners, wherein two first adjacent pile connection holes penetrating the prefabricated pipe piles and symmetrically arranged are further provided on the hole wall of the inner hole of the pipe pile, and the first adjacent pile connection holes corresponding to two adjacent prefabricated pipe piles are fastened together by first fasteners.

[0013] Furthermore, two adjacent prefabricated pipe piles are respectively connected to the adjustment plate through a first fastener;

[0014] The adjustment plate is provided with a circumferential adjustment hole and an axial adjustment hole, and the axial adjustment hole is arranged parallel to the axial direction of the prefabricated pipe pile;

[0015] The circumferential adjustment hole is perpendicular to the axial adjustment hole and cross-connected with the axial adjustment hole;

[0016] One of the first adjacent pile connection holes of two adjacent prefabricated pipe piles is fastened together with the circumferential adjustment hole or the axial adjustment hole through the first fastener;

[0017] Another of the first adjacent pile connection holes of two adjacent prefabricated pipe piles is fastened together with the circumferential adjustment hole or the axial adjustment hole through the first fastener.

[0018] Furthermore, before injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles through the grouting holes using the grouting equipment, the method further includes the following steps:

[0019] An anchor connection seat is fixed between two adjacent prefabricated pipe piles, wherein a second adjacent pile connection hole penetrating the prefabricated pipe pile is further provided on the hole wall of the inner hole of the pipe pile, and a second fastening hole corresponding to the second adjacent pile connection holes of the two adjacent prefabricated pipe piles is provided on the anchor connection seat, and the second adjacent pile connection hole is connected with the second fastening hole through a second fastener;

[0020] An anchor body is constructed in the soil on the soil-facing side, and then one end of the anchor cable is connected to the anchor connection seat, and the other end is embedded in the soil and fixed by an anchor, wherein the anchor connection seat is provided with an anchor connection hole for the other end of the anchor cable to pass through.

[0021] Furthermore, the grouting hole, the first adjacent pile connection hole and the second adjacent pile connection hole can all be detachably installed with plugs.

[0022] Furthermore, the grouting hole, the first adjacent pile connection hole and the second adjacent pile connection hole all include a first hole section and a second hole section with a hole diameter larger than that of the first hole section;

[0023] One end of the first hole section is connected to the inner hole of the pipe pile, and the other end is coaxially connected to one end of the second hole section;

[0024] The other end of the second hole section is connected to the outside of the prefabricated pipe pile.

[0025] Furthermore, after injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles through the grouting holes using the grouting equipment, the method further comprises the following steps:

[0026] The pile tops of the prefabricated pipe piles are connected together through a cap beam.

[0027] Furthermore, before injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles through the grouting holes using the grouting equipment, the method further includes the following steps:

[0028] The pile tops of the prefabricated pipe piles are connected together through a crown beam, wherein the crown beam is provided with a construction avoidance opening connected to the inner hole of the pipe pile.

[0029] Furthermore, the pile driving construction equipment includes a drilling rig, an auxiliary crane, an auger rod, a pile controller and a hole expansion drill bit;

[0030] The pile controller is used to fix the prefabricated pipe pile;

[0031] One end of the spiral drill rod is connected to the reaming drill bit, and the other end is connected to the drilling rig;

[0032] The auxiliary crane is used to hoist the auger rod and the drilling rig into the prefabricated pipe pile, or to hoist them out of the prefabricated pipe pile;

[0033] The drilling rig is used to drive the spiral drill rod to rotate, so as to drive the reaming drill bit to rotate.

[0034] It can be seen from the above technical solutions that the drilling and pipe pile foundation pit support construction method designed in this application has the following beneficial effects:

[0035] 1. The drilling and pipe pile foundation pit construction technology is adopted, which has the advantages of short construction period and no maintenance. It is also conducive to efficient construction in caves, soil caves and loose and broken strata, shortening the construction period.

[0036] 2. Inject solidified water-sealing materials into the gaps between prefabricated pipe piles through the grouting holes on the prefabricated pipe piles to achieve gap reinforcement and water-stopping treatment, avoiding the high cost and long cycle of reinforcement treatment using methods such as mixing piles, which is beneficial to reducing the construction cost of foundation pit support and giving full play to the advantage of short foundation pit support cycle using prefabricated pipe piles. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0038] Figure 1 This is a flow chart of Example 1 of a construction method for foundation pit support with pipe piles while drilling provided in this application;

[0039] Figure 2 This is a flow chart of Example 2 of a construction method for a foundation pit support with pipe piles while drilling provided in this application;

[0040] Figure 3 A schematic diagram of the construction structure of a pile sinking construction equipment for a drilling-while-drilling and pipe pile foundation pit support construction method provided in this application;

[0041] Figure 4 A schematic diagram of the structure of a prefabricated pipe pile in a method for drilling and pipe pile foundation pit support construction provided in this application;

[0042] Figure 5 A cross-sectional view of a prefabricated pipe pile for a construction method of a foundation pit support with pipe piles while drilling provided in this application;

[0043] Figure 6 A schematic diagram of the coordination of the grouting holes and plugging of the soil-facing side of the prefabricated pipe piles in a method for drilling and pipe pile foundation pit support construction provided in this application;

[0044] Figure 7A schematic diagram of a foundation pit support structure of a drilling-while-drilling and pipe pile foundation pit support construction method provided in this application;

[0045] Figure 8 for Figure 7 AA partial cross-sectional view;

[0046] Fig. 9 A structural schematic diagram of a connection adjustment plate of a drilling-while-drilling and pipe pile foundation pit support construction method provided in this application;

[0047] Fig.10 for Figure 7 BB partial cross-sectional view;

[0048] Fig.11 A schematic diagram of the anchoring state of a drilling-while-drilling pile foundation pit support construction method provided in this application;

[0049] In the figure: 1. drilling rig; 2. prefabricated pipe pile; 21. second adjacent pile connection hole; 22. soil-facing side grouting hole; 23. pipe pile gap grouting hole; 24. first adjacent pile connection hole; 25. pipe pile inner hole; 26. hole wall; 3. auger rod; 4. pile controller; 5. reamer drill bit; 6. plug; 7. anchor connection seat; 71. second fastening hole; 72. anchor connection hole; 8. bolt; 9. nut; 10. adjustment plate; 11. crown beam; 12. anchor cable; 13. anchor body; 101. axial adjustment hole; 102. circumferential adjustment hole. DETAILED DESCRIPTION

[0050] The technical solutions of the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present application, not all of them. All other embodiments obtained by ordinary technicians in this field without creative work based on the embodiments in the embodiments of the present application are within the scope of protection of the embodiments of the present application.

[0051] In the description of the embodiments of the present application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0052] In the description of the embodiments of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a replaceable connection, or an integral connection, it can be a mechanical connection, it can be an electrical connection, it can be a direct connection, it can be indirectly connected through an intermediate medium, and it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific circumstances.

[0053] The embodiment of the present application discloses a construction method for supporting a foundation pit with pipe piles while drilling.

[0054] See also Figure 1 as well as Figure 3 to Figure 4 An embodiment of a method for construction of a foundation pit support with pipe piles while drilling provided in the embodiments of the present application includes:

[0055] S1, use pile driving construction equipment to carry out prefabricated pipe pile driving construction to achieve the spacing of multiple prefabricated pipe piles, wherein the prefabricated pipe pile 2 is provided with a pipe pile inner hole 25 that penetrates itself along its own axial direction, that is, the prefabricated pipe device is a hollow structure, the pipe pile inner hole 25 can be a circular hole, the diameter of the prefabricated pipe pile 2 can be designed to be a large-diameter pipe pile of not less than 1000mm, and the diameter of the pipe pile inner hole 25 of the prefabricated pipe pile is not less than 650mm, which can be used for construction workers to enter the pipe pile inner hole 25 of the prefabricated pipe pile 2 for short-term construction work, and the hole wall 26 of the pipe pile inner hole 25 is provided with a grouting hole that penetrates the prefabricated pipe pile 2.

[0056] It should be noted that the pile driving construction equipment includes a drilling machine 1 , an auxiliary crane (not shown), an auger rod 3 , a pile controller 4 and a reamer drill bit 5 .

[0057] The pile controller 4 is used to fix the prefabricated pipe pile 2 to prevent the prefabricated pipe pile 2 from falling over.

[0058] One end of the spiral drill rod 3 is connected to the reaming drill bit 5, and the other end is connected to the drilling machine 1. The reaming drill bit 5 has a retractable structure. After the reaming drill bit 5 is retracted, the diameter is smaller than the inner diameter of the prefabricated pipe pile 2, and after the reaming drill bit 5 is opened, the diameter is larger than the outer diameter of the prefabricated pipe pile 2. The reaming drill bit 5 is opened and retracted by the friction force of the forward and reverse rotation or the drilling pressure control method.

[0059] The auxiliary crane is used to hoist the auger rod 3 and the drilling rig 1 into the prefabricated pipe pile 2, or to hoist them out of the prefabricated pipe pile 2; the drilling rig 1 is used to drive the auger rod 3 to rotate, so as to drive the reamer drill bit 5 to rotate. The upper part of the prefabricated pipe pile 2 is connected to the drilling rig 1, and the upper part of the auger rod 3 located in the prefabricated pipe pile 2 is connected to the drilling rig 1.

[0060] During construction, the auger rod 3 and the reamer bit 5 are connected as a whole, and the reamer bit 5 and the auger rod 3 in the retracted state are inserted into the prefabricated pipe pile 2 through an auxiliary crane, and the reamer bit 5 is a certain distance from the bottom of the prefabricated pipe pile 2.

[0061] During construction, driven by the drilling rig 1, the reaming drill bit 5 advances ahead of the prefabricated pipe pile 2 to perform reaming drilling, and the prefabricated pipe pile 2 completes the pile sinking construction synchronously with the drilling process. After the pile sinking construction is completed, the reaming drill bit 5 is retracted and lifted off from the prefabricated pipe pile 2, and the above process is repeated until the pile sinking construction is completed.

[0062] S2, use grouting equipment to inject curing water-sealing materials into the gaps between prefabricated pipe piles through the grouting holes. It should be noted that when there is water seepage or local soil loosening and falling in the gaps between the prefabricated pipe piles 2 for support, it is necessary to reinforce the gaps between the supporting piles. During the reinforcement process, the grouting holes are reached manually through the inner holes 25 of the prefabricated pipe piles 2, the grouting holes are opened, and the grouting pipes are connected. Then, high-pressure grouting equipment is used to inject curing water-sealing materials such as cement slurry or epoxy resin mortar to reinforce the gaps between the pipe piles or to stop water.

[0063] The drilling and pipe pile foundation pit support construction method designed in this application has the following beneficial effects:

[0064] 1. The drilling and pipe pile foundation pit construction technology is adopted, which has the advantages of short construction period and no maintenance. It is also conducive to efficient construction in caves, soil caves and loose and broken strata, shortening the construction period.

[0065] 2. Inject solidified water-sealing material into the gaps between the prefabricated pipe piles 2 through the grouting holes on the prefabricated pipe piles 2 to achieve gap reinforcement and water-stopping treatment, avoiding the high cost and long cycle of reinforcement treatment using methods such as mixing piles, which is beneficial to reducing the construction cost of foundation pit support and giving full play to the advantage of short foundation pit support cycle using prefabricated pipe piles 2.

[0066] The above is an embodiment of the present invention provided by the embodiment of a method for the construction of a foundation pit with a pipe pile while drilling. The following is an embodiment of the present invention provided by the embodiment of a method for the construction of a foundation pit with a pipe pile while drilling. For details, please refer to Figures 1 to 11 .

[0067] Based on the solution of the above embodiment 1:

[0068] Furthermore, there are at least two grouting holes, at least one grouting hole is arranged toward the soil facing side to form a soil facing side grouting hole 22, and at least one grouting hole is arranged toward the adjacent prefabricated pipe piles 2 to form a pipe pile gap grouting hole 23.

[0069] Furthermore, before S2, the following steps are also included:

[0070] S10, each prefabricated pipe pile is fastened together in sequence by the first fastener, wherein the hole wall 26 of the inner hole 25 of the pipe pile is also provided with two first adjacent pile connection holes 24 that penetrate the prefabricated pipe pile 2 and are symmetrically arranged, and the first adjacent pile connection holes 24 corresponding to two adjacent prefabricated pipe piles 2 are fastened together by the first fastener. It can be understood that below the pile top of the prefabricated pipe pile 2, the prefabricated pipe piles 2 can be connected as a whole at intervals along the longitudinal direction, and the specific arrangement number is reasonably arranged according to the actual passive pressure and the excavation depth. Adjacent prefabricated pipe piles 2 are connected by the adjacent first adjacent pile connection holes 24 facing the side of the adjacent prefabricated pipe piles 2, and the first adjacent pile connection holes 24 are symmetrically arranged on the prefabricated pipe pile 2, and the first adjacent pile connection holes 24 of all prefabricated pipe piles 2 are at the same height.

[0071] The first fastener includes a bolt 8 and a nut 9. The bolt 8 is used to pass through the two adjacent first adjacent pile connection holes 24 from the hole wall 26 on one side between two adjacent prefabricated pipe piles 2, and is fixed by the nut 9 through threaded connection in the hole wall 26 on the other side. The side where the head of the bolt 8 contacts the hole wall 26 can be provided with an arc surface consistent with the arc of the hole wall 26, and the contact area can be increased by increasing the diameter of the head of the bolt 8 to improve the contact stress state of the head of the bolt 8. The side where the nut 9 contacts the hole wall 26 can also be provided with an arc surface with the same arc as the hole wall 26, and a large outer diameter nut 9 can be customized to increase the contact area.

[0072] Furthermore, since it is difficult to completely align the first adjacent pile connection holes 24 of adjacent prefabricated pipe piles 2 during the actual construction process, in order to better solve this problem, the two adjacent prefabricated pipe piles 2 in the present application are respectively connected to the adjustment plate 10 through a first fastener, that is, an additional adjustment plate 10 is provided, and the two prefabricated pipe piles 2 are flexibly connected through the adjustment plate 10.

[0073] The adjusting plate 10 is provided with an oblong circumferential adjusting hole 102 and an axial adjusting hole 101 . The axial adjusting hole 101 is arranged parallel to the axial direction of the prefabricated pipe pile 2 .

[0074] The circumferential adjustment hole 102 is perpendicular to the axial adjustment hole 101 and cross-connected with the axial adjustment hole 101 .

[0075] One first adjacent pile connection hole 24 of two adjacent prefabricated pipe piles 2 is fastened together with the circumferential adjustment hole 102 or the axial adjustment hole 101 through a first fastener; the other first adjacent pile connection hole 24 of two adjacent prefabricated pipe piles 2 is fastened together with the circumferential adjustment hole 102 or the axial adjustment hole 101 through a first fastener.

[0076] Specifically, the bolt 8 can pass through the circumferential adjustment hole 102 or the axial adjustment hole 101 of the adjustment plate 10 and then be fastened by the nut 9. The axial adjustment hole 101 parallel to the axis of the prefabricated pipe pile 2 is an axial spacing adjustment hole, which can adjust the height of the pipe pile along the axial direction; the circumferential adjustment hole 102 parallel to the circumference of the prefabricated pipe pile 2 is a circumferential spacing adjustment hole, which can adjust the distance along the circumference of the pipe pile. Under this design, even if the two first adjacent pile connection holes 24 are not completely aligned, they can be well fastened together by connecting with the adjustment plate 10.

[0077] Furthermore, before step S2, the following steps are also included:

[0078] S20, fix the anchor connection seat between two adjacent prefabricated pipe piles, wherein the hole wall 26 of the inner hole 25 of the pipe pile is also provided with a second adjacent pile connection hole 21 penetrating the prefabricated pipe pile 2, and the anchor connection seat 7 is provided with a second fastening hole 71 corresponding to the second adjacent pile connection holes 21 of the two adjacent prefabricated pipe piles 2, and the second adjacent pile connection hole 21 is connected to the second fastening hole 71 through a second fastener. Specifically, the anchor connection seat 7 can be a rectangular parallelepiped structure, and the contact position with the prefabricated pipe pile 2 is an arc surface structure with the same arc as the outer wall of the prefabricated pipe pile 2. The length of the anchor connection seat 7 is greater than the center distance between the two adjacent prefabricated pipe piles 2, and the anchor connection seat 7 acts as a spacing support structure. The second fastener may also include a bolt 8 and a nut 9, and the second adjacent pile connection hole 21 and the second fastening hole 71 are arranged with equal diameter and coaxial center.

[0079] The anchoring connection seat 7 and the prefabricated pipe pile 2 are fixed by bolts 8, and the bolts 8 pass through the second fastening holes 71 and the second adjacent pile connection holes 21. The bolts 8 are provided with nuts 9 on the inner side of the hole wall 26, and the nuts 9 and the bolts 8 are fixed by threaded connection. In order to further increase the contact area between the nuts 9 and the prefabricated pipe pile 2 and improve the local stress state, the nuts 9 can be customized nuts 9, and the nuts 9 have a larger outer diameter, and the contact surface between the nuts 9 and the hole wall 26 of the prefabricated pipe pile 2 is an arc surface with the same curvature. The fixing operation of the anchoring connection seat 7 is completed by the workers through the inner hole 25 of the pipe pile and the workers outside the pipe pile in cooperation.

[0080] S30, construct an anchor body in the soil on the soil facing side, then connect one end of the anchor cable to the anchor connection seat, and embed the other end into the soil and fix it through the anchor, wherein the anchor connection seat 7 is provided with an anchor connection hole 72 for the other end of the anchor cable 12 to pass through. Specifically, the center of the anchor connection seat 7 is provided with an anchor connection hole 72 inclined downward toward the soil facing side for the anchor cable 12 to pass through. The anchor connection hole 72 is located between the gaps between two adjacent prefabricated pipe piles 2. One end of the anchor cable 12 passes through the anchor connection hole 72 and is fixed to the anchor connection seat 7, and the other end is embedded deep into the soil, and an anchor body 13 is constructed for fixing.

[0081] After the precast pile support construction is completed, if there is a condition of excessive soil pressure, the support capacity of the precast pipe piles 2 can be strengthened by anchoring between two adjacent precast pipe piles 2. The anchoring positions are arranged at intervals along the longitudinal direction downward, and are reasonably distributed according to the soil pressure monitoring or calculation data. The anchoring positions are arranged at intervals along the horizontal direction, and the interval between the two anchoring positions is a number of adjacent precast pipe piles 2 or dozens of precast pipe piles 2, which are also reasonably arranged according to the on-site construction and calculation conditions. It can be understood that during the longitudinal anchoring construction, if multiple anchoring positions are to be constructed, multiple anchoring connectors 7 can be arranged in the longitudinal direction, and if multiple anchoring positions are to be constructed in the horizontal direction, after the anchoring connector 7 is constructed in a group of precast pipe piles 2, the anchoring connector 7 can be constructed in a group of precast pipe piles 2 separated by a certain number.

[0082] Furthermore, the grouting holes, the first adjacent pile connection holes 24 and the second adjacent pile connection holes 21 can each be designed in multiple groups. When designed in multiple groups, they can be arranged at intervals along the axis of the prefabricated pipe pile 2 without limitation.

[0083] The grouting holes, the first adjacent pile connection holes 24 and the second adjacent pile connection holes 21 are all detachably installed with plugs 6. During pile sinking construction, the plugs 6 can prevent clogging by mud and sand. In the subsequent construction stage, construction personnel can use tools to push and remove them from the inside of the prefabricated pipe pile 2 as needed.

[0084] Furthermore, the grouting hole, the first adjacent pile connection hole 24 and the second adjacent pile connection hole 21 all include a first hole section and a second hole section with a larger hole diameter than the first hole section. One end of the first hole section is connected to the inner hole 25 of the pipe pile, and the other end is coaxially connected to one end of the second hole section. The other end of the second hole section is connected to the outside of the prefabricated pipe pile 2. The grouting hole, the first adjacent pile connection hole 24 and the second adjacent pile connection hole 21 can be steel thin-walled circular tubes, which are pre-buried and formed during the processing stage of the prefabricated pipe pile 2. Before the prefabricated pipe pile 2 is constructed, a two-section round rod-shaped plug 6 is used. The diameters of the two sections of the round rod of the plug 6 are slightly smaller than the inner diameter of the first hole section and the second hole section. The grouting hole, the first adjacent pile connection hole 24 and the second adjacent pile connection hole 21 are blocked from the outside of the prefabricated pipe pile 2 to prevent clogging by mud and sand. The material of the plug 6 can be plastic, steel, concrete, wood, etc. The grouting hole, the first adjacent pile connection hole 24 and the second adjacent pile connection hole 21 can be summarized by a hypernym, such as a through circular hole, which includes the grouting hole, the first adjacent pile connection hole 24 and the second adjacent pile connection hole 21.

[0085] The present application utilizes the second adjacent pile connection hole 21 and the first adjacent pile connection hole 24 opened in the prefabricated pipe pile 2, combined with the permeability of the internal space of the large-diameter prefabricated pipe pile 2, and can achieve the fixation of the anchor connection seat 7 and the connection and fixation of the adjacent prefabricated pipe piles 2 with the assistance of construction personnel. The connection structure is simple, the construction period is short, and the adjustability is strong. The anchor construction and the connection of adjacent pipe piles are beneficial to improving the integrity and support capacity of the support piles.

[0086] Furthermore, after step S2, the following steps are also included:

[0087] S40, connecting the tops of the prefabricated pipe piles together through the cap beam. In order to improve the integrity of the supporting piles, it is necessary to fix the adjacent prefabricated pipe piles 2 as a whole to jointly bear the supporting function. To this end, a concrete cap beam 11 is constructed on the top of each prefabricated pipe pile 2 to connect the tops of the prefabricated pipe piles 2 as a whole. In order not to affect the construction workers' construction work inside the prefabricated pipe pile 2, the construction of the cap beam 11 is arranged after step S2 to achieve the final construction.

[0088] Furthermore, before step S2, the following steps are also included:

[0089] S40, connect the tops of the prefabricated pipe piles together through a crown beam, wherein the crown beam 11 is provided with a construction avoidance opening connected to the inner hole 25 of the pipe pile. It is understandable that the construction of the crown beam 11 can also be before step S2, but the construction avoidance opening needs to be reserved. The crown beam 11 connected to the top of the prefabricated pipe pile 2 can be a steel structure, and a circular construction avoidance opening is set in the crown beam 11 structure. The steel crown beam 11 is connected to the top of the prefabricated pipe pile 2 by bolts 8, that is, it is connected as a whole by threads. The crown beam 11 can also be connected to the anchor cable 12 to achieve support reinforcement.

[0090] The above is a detailed introduction to the construction method of drilling and pipe pile foundation pit support provided by the present application. For general technicians in this field, according to the ideas of the embodiments of the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A method for construction of foundation pit support by drilling and pipe pile, characterized in that: Includes steps: A pile sinking construction device is used to carry out pile sinking construction of a prefabricated pipe pile (2) so as to realize the spaced arrangement of a plurality of the prefabricated pipe piles (2), wherein the prefabricated pipe pile (2) is provided with a pipe pile inner hole (25) penetrating the prefabricated pipe pile (2) along its own axial direction, and a grouting hole penetrating the prefabricated pipe pile (2) is provided on a hole wall (26) of the pipe pile inner hole (25), and the grouting holes are spaced along the axis of the prefabricated pipe pile (2); Using grouting equipment to inject solidified water-sealing material into the gaps between the prefabricated pipe piles (2) through the opened grouting holes; Before the method of injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles (2) through the grouting holes using the grouting equipment, the method further comprises the following steps: The prefabricated pipe piles (2) are sequentially fastened together by means of a first fastener, wherein the hole wall (26) of the inner hole (25) of the pipe pile is further provided with two first adjacent pile connection holes (24) penetrating the prefabricated pipe pile (2) and symmetrically arranged, and the first adjacent pile connection holes (24) corresponding to two adjacent prefabricated pipe piles (2) are fastened together by means of a first fastener; Two adjacent prefabricated pipe piles (2) are respectively connected to the adjustment plate (10) via a first fastener; The adjustment plate (10) is provided with a circumferential adjustment hole (102) and an axial adjustment hole (101), and the axial adjustment hole (101) is arranged parallel to the axial direction of the prefabricated pipe pile (2); The circumferential adjustment hole (102) is used to adjust the distance along the circumference of the pipe pile; The axial adjustment hole (101) is used to adjust the height of the pipe pile along the axial direction; The circumferential adjustment hole (102) is perpendicular to the axial adjustment hole (101), and is cross-connected with the axial adjustment hole (101); One of the first adjacent pile connection holes (24) of two adjacent prefabricated pipe piles (2) is fastened together with the circumferential adjustment hole (102) or the axial adjustment hole (101) through the first fastener; Another of the first adjacent pile connection holes (24) of two adjacent prefabricated pipe piles (2) is fastened together with the circumferential adjustment hole (102) or the axial adjustment hole (101) through the first fastener; Before the method of injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles (2) through the grouting holes using the grouting equipment, the method further comprises the following steps: An anchor connection seat (7) is fixed between two adjacent prefabricated pipe piles (2), wherein a second adjacent pile connection hole (21) penetrating the prefabricated pipe pile (2) is also provided on the hole wall (26) of the inner hole (25) of the pipe pile, and a second fastening hole (71) corresponding to the second adjacent pile connection holes (21) of the two adjacent prefabricated pipe piles (2) is provided on the anchor connection seat (7), and the second adjacent pile connection hole (21) is connected to the second fastening hole (71) by a second fastener; An anchor body (13) is constructed in the soil on the soil-facing side, and then one end of the anchor cable (12) is connected to the anchor connection seat (7), and the other end is embedded in the soil and fixed by an anchor, wherein the anchor connection seat (7) is provided with an anchor connection hole (72) for the other end of the anchor cable (12) to pass through; After injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles (2) through the grouting holes using the grouting equipment, the method further comprises the following steps: The pile tops of the prefabricated pipe piles (2) are connected together through a crown beam (11), wherein the crown beam (11) is also connected to an anchor cable (12) to achieve support and reinforcement processing; Before the method of injecting the solidified water-sealing material into the gaps between the prefabricated pipe piles (2) through the grouting holes using the grouting equipment, the method further comprises the following steps: The pile tops of the prefabricated pipe piles (2) are connected together via a cap beam (11), wherein the cap beam (11) is provided with a construction avoidance opening connected to the inner hole (25) of the pipe pile.

2. The method for supporting a foundation pit with a pile while drilling according to claim 1, characterized in that: There are at least two grouting holes, at least one of which is arranged toward the soil facing side to form a soil facing side grouting hole (22), and at least one of which is arranged toward the adjacent prefabricated pipe pile (2) to form a pipe pile gap grouting hole (23).

3. The method for supporting a foundation pit with a pile while drilling according to claim 1, characterized in that: The grouting hole, the first adjacent pile connection hole (24) and the second adjacent pile connection hole (21) can all be detachably provided with plugs (6).

4. The method for supporting a foundation pit with a pile while drilling according to claim 3 is characterized in that: The grouting hole, the first adjacent pile connection hole (24) and the second adjacent pile connection hole (21) all comprise a first hole section and a second hole section with a hole diameter larger than that of the first hole section; One end of the first hole section is connected to the inner hole (25) of the pipe pile, and the other end is coaxially connected to one end of the second hole section; The other end of the second hole section is connected to the outside of the prefabricated pipe pile (2).

5. The method for supporting a foundation pit with a pile while drilling according to claim 1, characterized in that: The pile driving construction equipment comprises a drilling machine (1), an auxiliary crane, a spiral drill rod (3), a pile controller (4) and a hole expansion drill bit (5); The pile controller (4) is used to fix the prefabricated pipe pile (2); One end of the spiral drill rod (3) is connected to the reaming drill bit (5), and the other end is connected to the drilling machine (1); The auxiliary crane is used to hoist the auger rod (3) and the drilling rig (1) into the prefabricated pipe pile (2), or to hoist them out of the prefabricated pipe pile (2); The drilling machine (1) is used to drive the spiral drill rod (3) to rotate, thereby driving the reaming drill bit (5) to rotate.

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