Prefabricated micro pile with coupling stress adjustment, monitoring and rapid assembly functions and construction method

Abstract

The application discloses a prefabricated micro pile with coupling stress deployment, monitoring and rapid assembly functions and a construction method, and belongs to the field of slope and landslide prevention and control, comprising a prefabricated micro pile pipe pile, a connecting steel base, connecting bolts, a pile sinking steel base, a pile-anchor coupling connection top plate, an anchor cable, a monitoring wire harness and a construction process. The prefabricated micro pile pipe pile is divided into low-strength pipe piles, medium-strength pipe piles and high-strength pipe piles, and stress deployment can be performed according to the stress differences of the pile bodies. Monitoring sensors are arranged in the prefabricated micro pile pipe pile, and a prefabricated grouting method is adopted, so that the convenience of underground monitoring and the timeliness of prevention and control of slope and landslide prevention and control are effectively improved. The support of the connecting steel base, the connecting bolts and the pile sinking steel base makes the deployment and assembly of the prefabricated micro pile pipe pile and the pile sinking operation more rapid and efficient. The pile-anchor coupling connection top plate forms a pile-anchor coupling prevention and control structure by connecting the prefabricated micro pile pipe pile and the anchor cable, and further enhances the prevention and control capability of the prefabricated micro pile. The application improves the stress deployment, underground monitoring, rapid assembly and coupling prevention and control performance of the prefabricated micro pile, and has important significance for the prevention and control of slopes and landslides.

Description

Technical Field

[0001] The present invention relates to the field of slope and landslide prevention and control, and in particular to a prefabricated micro pile with coupled force allocation, monitoring and rapid assembly functions and a construction method. Background Art

[0002] Micropiles are increasingly being used in slope reinforcement and landslide control due to their advantages, including trenchless mechanical drilling, strong adaptability to ground conditions, flexible pile placement, minimal disturbance to sliding bodies, and safety and speed. The traditional micropile construction process includes site preparation, equipment installation, drilling, scouring, and grouting and compaction.

[0003] However, the traditional micropile construction process has the following three problems: (1) The forces transmitted to the micropile by the objects of different deformation and failure modes are different, while the various properties of traditional micropile are relatively uniform from the bottom to the top of the pile, and the force cannot be adjusted according to the difference in force, which makes the prevention and control project uneconomical. (2) The micropile constructed by grouting and compaction technology will have problems such as pile body segregation, diameter reduction and pile breakage, which will reduce the anti-slip ability of the micropile; in addition, the grouting concrete requires a certain solidification and curing time to reach the corresponding strength, which may miss the best time for slope or landslide prevention and control. (3) The diameter of the micropile is relatively small compared to the diameter of the anti-slip pile. During the grouting process of the micropile, it is difficult to lay monitoring pipes or monitoring sensors in the pile like anti-slip piles, which makes underground monitoring of slope or landslide prevention and control inconvenient. Therefore, in order to effectively solve the above three problems, providing a prefabricated micropile and construction method with coupled force adjustment, monitoring and rapid assembly functions is of great significance for the rapid, economical and effective prevention and control of slopes and landslides. Summary of the Invention

[0004] The purpose of the present invention is to provide a prefabricated micro pile and a construction method with coupled force adjustment, monitoring and rapid assembly functions.

[0005] The technical solution of the present invention is a prefabricated micro pile with coupled force adjustment, monitoring and rapid assembly functions, including a prefabricated micro pile pipe pile, a connecting steel seat, connecting bolts, a pile sinking steel seat, a pile anchor coupling connecting top plate and a monitoring harness.

[0006] The prefabricated micro-pile pipe piles are divided into three categories: low-strength pipe piles, medium-strength pipe piles and high-strength pipe piles; the low-strength pipe piles are composed of pipe pile steel pipes, steel cages, monitoring wire harnesses, PVC pipes and concrete; the medium-strength pipe piles are composed of pipe pile steel pipes, rods, monitoring wire harnesses, PVC pipes and concrete; the high-strength pipe piles are composed of pipe pile steel pipes, steel cages, rods, monitoring wire harnesses, PVC pipes and concrete; the pipe pile steel pipes, steel cages, rods, monitoring wire harnesses, PVC pipes and concrete are all axially symmetrically distributed on the cross section, and in addition, a pipe pile grouting hole is made on the transverse axis direction of the connecting steel plate end of the pipe pile steel pipe; therefore, according to the difference in the stress on the pile body, prefabricated micro-pile pipe piles of corresponding strength can be selected for stress adjustment.

[0007] A connecting steel seat is welded at each end of the top and bottom of the prefabricated micropile pipe, and the connecting steel seat is composed of a lower connecting steel plate, an upper connecting steel plate, a stiffening rib and a grouting steel pipe; a prefabricated micropile grouting hole is formed at the center of the lower connecting steel plate, and a monitoring harness hole is formed at each end of the axis of the prefabricated micropile grouting hole; a prefabricated micropile grouting hole is formed at the center of the upper connecting steel plate, and a monitoring harness hole and two connecting bolt holes are formed at each end of the axis of the prefabricated micropile grouting hole, and the angles between the connecting bolt holes are right angles; a grouting steel pipe and stiffening ribs are welded between the lower connecting steel plate and the upper connecting steel plate, and the stiffening ribs are distributed in the horizontal and vertical axis directions of the grouting steel pipe, and a grouting steel pipe grouting hole is formed between each stiffening rib, and the angles between the grouting steel pipe grouting holes are right angles.

[0008] The connecting steel seats are fastened together by connecting bolts, and a prefabricated micropile is formed by fastening a plurality of prefabricated micropile pipes and connecting steel seats. The prefabricated micropile is connected to a pile sinking steel seat at the bottom and a pile anchor coupling connection top plate at the top. The pile sinking steel seat is composed of a connecting steel seat and a pile sinking steel seat stiffening cone, which are welded to the lower connecting steel plate of the connecting steel seat at a right angle to each other. The pile anchor coupling connection top plate has an anchor cable connection hole in the middle and top plate bolt holes and top plate grouting holes at both ends. These top plate bolt holes and top plate grouting holes are aligned with the prefabricated micropile grouting holes, connecting bolt holes, and monitoring harness holes in the upper connecting steel plate of the connecting steel seat. The pile anchor coupling connection top plate effectively forms a coupling prevention and control structure between the prefabricated micropile and the anchor cable. The monitoring harness is composed of monitoring sensors and monitoring sensor connecting cables, and is symmetrically distributed within the prefabricated micropile.

[0009] The construction method includes the following steps: S1. Material configuration, S2. Equipment configuration, S3. Site cleaning, S4. Drilling and punching, S5. Prefabricated micro-pile preparation, assembly and pile sinking, S6. Anchor cable installation, S7. Grouting, S8. Anchor cable tensioning, locking and anchor sealing, S9. Monitoring and testing.

[0010] Compared with the prior art, the present invention has the following beneficial effects:

[0011] 1. The prefabricated micropile pipe piles of the present invention can be divided into three categories according to the size of the strength grade: low-strength pipe piles, medium-strength pipe piles and high-strength pipe piles. Therefore, according to the stress difference of the pile body, the prefabricated micropile pipe piles of corresponding strength can be selected to carry out stress adjustment, thereby improving the economy of the prevention and control project.

[0012] 2. The prefabricated micropile pipe pile of the present invention has been grouting-treated during prefabrication and the pile length can be adjusted. Prefabricated grouting can effectively reduce the problems of pile body segregation, diameter reduction and pile breakage that occur during on-site grouting and reduce the anti-slip ability of the micropile. In addition, the prefabricated micropile pipe pile through prefabricated grouting has reached the required strength, and on-site assembly can achieve timely and rapid reinforcement of slopes or landslides.

[0013] 3. The longitudinal axis of the prefabricated micropile pipe pile of the present invention is provided with a prefabricated micropile grouting hole, and the connecting steel seat is provided with a grouting steel pipe grouting hole, which can be used as a monitoring hole for the groundwater level before tightening and grouting in the project. After tightening and grouting, the tightness of the prefabricated micropile and the rock and soil around the pile can be effectively improved.

[0014] 4. The corresponding monitoring equipment is already arranged when the prefabricated micropile pipe piles of the present invention are prefabricated. The prefabricated micropile monitoring pipe piles can be flexibly arranged according to actual needs, thereby improving the convenience of underground monitoring for slope or landslide prevention.

[0015] To sum up: the prefabricated micro pile and construction method of the present invention with coupled force allocation, monitoring and rapid assembly functions can realize force allocation of pile body force differences, can realize rapid assembly, timely prevention and control, and can realize convenient and flexible underground monitoring, thereby improving the ability to prevent and control slopes or landslides. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the prefabricated micro pile structure of the present invention

[0017] Figure 2 A-A' cross-sectional view of the prefabricated micropile structure of the present invention

[0018] Figure 3 Schematic diagram of the top plate of the prefabricated micropile-anchor cable coupling structure of the present invention

[0019] Figure 4 This is the construction flow chart of the prefabricated micro pile-anchor cable coupling structure for preventing and controlling landslides.

[0020] Figure 5 Schematic diagram of the prefabricated micro pile-anchor cable coupling structure for preventing landslides according to the present invention

[0021] The numbers in the figure are: 1-prefabricated micropile pipe pile, 1.1-low-strength pipe pile, 1.2-medium-strength pipe pile, 1.3-high-strength pipe pile, 1.3.1-pipe pile steel pipe, 1.3.2-reinforcement cage, 1.3.3-PVC pipe, 1.3.4-rod, 1.3.5-concrete, 1.4-pipe pile grouting hole, 2-connecting steel seat, 2.1-lower connecting steel plate, 2.2-upper connecting steel plate, 2.2.1-prefabricated micropile grouting hole, 2.2.2-connecting bolt hole, 2.2.3-monitoring harness hole, 2.3-stiffening rib , 2.4- grouting steel pipe, 2.4.1- grouting hole of grouting steel pipe, 3- connecting bolt, 4- pile steel seat, 4.1- pile steel seat stiffening rib cone, 5- pile-anchor coupling connection top plate, 5.1- top plate bolt hole, 5.2- anchor cable connection hole, 5.3- top plate grouting hole, 6- anchor cable, 6.1- anchor cable free section, 6.2- anchor, 6.3- wedge pad, 6.4- anchor cable anchoring section, 7- monitoring harness, 7.1- monitoring sensor, 7.2- monitoring sensor connecting line, 8- landslide, 8.1- sliding body, 8.2- sliding bed. DETAILED DESCRIPTION

[0022] The present invention will be further described below with reference to the accompanying drawings and examples, but they are not intended to limit the present invention.

[0023] Embodiment. A prefabricated micro pile and construction method with coupled force adjustment, monitoring and rapid assembly functions, comprising: Figure 1-5 As shown. It includes prefabricated micro pile 1, connecting steel base 2, connecting bolts 3, pile steel base 4, pile anchor coupling connecting top plate 5, anchor cable 6, monitoring harness 7 and construction process Figure 4 .

[0024] The connecting steel base 2 is composed of a lower connecting steel plate 2.1, an upper connecting steel plate 2.2, stiffening ribs 2.3 and a grouting steel pipe 2.4. The lower connecting steel plate 2.1 and the upper connecting steel plate 2.2 are made by cutting discs with a machining diameter and thickness on the steel plates, and then processing the prefabricated micro pile grouting holes 2.2.1, the connecting bolt holes 2.2.2 and the monitoring harness holes 2.2.3; the stiffening ribs 2.3 are made by cutting the steel plates; the grouting steel pipe 2.4 is made by cutting the hollow steel pipe, and then drilling four grouting steel pipe grouting holes 2.4.1 in the middle of the longitudinal axis of the grouting steel pipe 2.4; the welding assembly method of the connecting steel base 2 is as follows: first, place the lower connecting steel plate 2.1 at the bottom, and then place the grouting steel pipe 2.4 Place it on the surface of the connecting steel plate 2.1 and center it, and weld the contact parts between the two. Then place the upper connecting steel plate 2.2 on the surface of the grouting steel pipe 2.4 and center it, and keep it aligned with the center of the prefabricated micropile grouting hole 2.2.1, the connecting bolt hole 2.2.2 and the monitoring harness hole 2.2.3 of the lower connecting steel plate 2.1, and weld the contact parts between the two. Then arrange the stiffening rib 2.3 at right angles between the lower connecting steel plate 2.1 and the upper connecting steel plate 2.2, and contact it with the grouting steel pipe 2.4, and weld the contact parts between the two. Be careful not to block the grouting hole 2.4.1 of the grouting steel pipe.

[0025] Prefabricated micropiles 1 are divided into three categories: low-strength pipe piles 1.1, medium-strength pipe piles 1.2, and high-strength pipe piles 1.3. The steel pipe 1.3.1 is made by cutting steel pipe, with a grouting hole 1.4 drilled above the longitudinal axis of the steel pipe 1.3.1. The steel cage 1.3.2 is made by tying together round thin-diameter steel bars. The PVC pipe 1.3.3 is made by cutting PVC pipe, the rod 1.3.4 is made by cutting rod, and the concrete 1.3.5 is grouting concrete. Low-strength pipe piles 1.1, medium-strength pipe piles 1.2, and high-strength pipe piles 1.3 are produced by adjusting the quantity and specifications of the steel cage 1.3.2, PVC pipe 1.3.3, rod 1.3.4, and concrete 1.3.5.

[0026] The welding combination method of the prefabricated micro pile pipe pile 1 and the connecting steel base 2 is as follows: first, the connecting steel base 2 is placed at the bottom, and the lower connecting steel plate 2.1 thereof is directed upwards; secondly, the lower part of the prefabricated micro pile pipe pile 1 is centered with the lower connecting steel plate 2.1, and the contact parts of the two are welded; then, the number and specifications of the steel cage 1.3.2, the PVC pipe 1.3.3 and the rod 1.3.4 are configured according to the strength requirements and are kept axially symmetrical in the cross section; at the same time, the monitoring sensors 7.1 are reasonably arranged according to the monitoring requirements, and are connected in series using the monitoring sensor connecting wires 7.2 to form the monitoring harness 7; then, the concrete 1.3.5 is poured. The concrete is poured and vibrated to compact it. When concrete 1.3.5 overflows from the pile grouting hole 1.4, the pouring is stopped. Next, the lower connecting steel plate 2.1 of the connecting steel base 2 is placed on the upper part of the prefabricated micropile pile 1, and is kept aligned with the prefabricated micropile grouting hole 2.2.1, the connecting bolt hole 2.2.2, and the monitoring harness hole 2.2.3 of the connecting steel base 2 welded to the lower part of the prefabricated micropile pile 1. The contact parts of the two are welded. Next, the monitoring harness 7 is led out from the monitoring harness hole 2.2.3. Then, concrete 1.3.5 is poured from the pile grouting hole 1.4 and vibrated to compact it until the prefabricated micropile pile 1 is completely filled. After the two ends of the prefabricated micropile pile 1 are welded to the steel base 2, a prefabricated micropile body is formed. Multiple prefabricated micropile bodies can be connected in series through the connecting bolts 3.

[0027] The pile-driving steel base 4 consists of a connecting steel base 2 and a pile-driving steel base stiffener cone 4.1. The pile-driving steel base stiffener cone 4.1 is made by cutting steel plate and welded to the lower connecting steel plate 2.1 of the connecting steel base 2 at a right angle. The pile-anchor coupling connecting top plate 5 is made by cutting steel plate. Anchor cable connection holes 5.2 are drilled in the center of the pile-anchor coupling connecting top plate 5, and top plate bolt holes 5.1 and top plate grouting holes 5.3 are drilled at both ends. These top plate bolt holes 5.1 and top plate grouting holes 5.3 must align with the prefabricated micropile grouting holes 2.2.1, connection bolt holes 2.2.2, and monitoring harness holes 2.2.3 in the upper connecting steel plate 2.2 of the connecting steel base 2. The pile-driving steel base 4 is securely connected to the lower end of the prefabricated micropile body via connecting bolts 3. The pile-anchor coupling connection top plate 5 is firmly connected to the uppermost end of the prefabricated micropile body via the connecting bolts 3 .

[0028] The construction method includes the following steps:

[0029] S1. Material configuration.

[0030] S101. Arrange the required materials according to the design and construction plans, including high-, medium-, and low-strength prefabricated micropile pipe piles 1 with connecting steel bases 2 welded at both ends, connecting bolts 3, pile-sunk steel bases 4, pile-anchor coupling connecting top plates 5, anchor cables 6, and concrete 1.3.5. At the same time, check the quality of the materials, number them, and record them.

[0031] S2. Device configuration.

[0032] S201. Configure the required equipment according to the design and construction plans, including excavators, geological drills, and high-pressure grouting machines, and inspect and debug them to ensure that the equipment can operate normally, and prepare the necessary tools and accessories.

[0033] S3. Site cleanup.

[0034] S301. Clean up the construction site, including leveling the site for the placement of prefabricated micropiles and anchor cables, transport routes, removing debris, and cleaning ditches. At the same time, set up construction signs and safety warning signs to ensure the safety of the construction site.

[0035] S4. Hole forming and punching.

[0036] S401. Use a geological drilling rig to drill holes based on the spatial structural characteristics of the prefabricated micropiles (parameters such as diameter, layout form and rock embedment depth) and the spatial structural characteristics of the anchor cables (parameters such as length, diameter and spacing).

[0037] S402. After the geological drilling rig has completed the hole, flush the hole with water.

[0038] S5. Prefabricated micropiles preparation, assembly and pile sinking.

[0039] S501. The geological drilling process can be used to determine the engineering geology and hydrogeology of the slope or landslide. Precast micropiles at corresponding distances above and below the deformation failure surface of the slope or landslide must have a strength of 1.3 times that of a high-strength pipe pile. The rock-embedded section of the precast micropiles must have a strength of 1.2 times that of a medium-strength pipe pile. The section of the precast micropiles near the slope surface must have a strength of 1.1 times that of a low-strength pipe pile.

[0040] S502. Prefabricated Micropile Assembly Process: The pile-sinking steel base 4, prefabricated micropile pipe 1, and pile-anchor coupling top plate 5 are tightly connected using connecting bolts 3. The pile-sinking steel base 4 is connected to the bottom of the prefabricated micropile, and the pile-anchor coupling top plate 5 is connected to the top of the prefabricated micropile. The strength of the prefabricated micropile pipe 1 is determined based on the spatial distribution characteristics of the prefabricated micropile in S501.

[0041] S503. The prefabricated micro piles are assembled and driven simultaneously. After the driving of the piles is completed, the prefabricated micro piles are connected to the top plate 5 by means of a pile-anchor coupling connection.

[0042] S6. Anchor cable installation.

[0043] S601. Install anchor cables according to the design and construction plans. During the installation process, pay attention to the control of parameters such as the length, diameter and spacing of the anchor cables, and number and record them.

[0044] S7. Grouting.

[0045] S701. Includes grouting of prefabricated micropiles and anchor cables. Concrete is poured into the top plate grouting holes 5.3 to ensure close contact and secure anchorage between the prefabricated micropiles and the rock and soil. The actual grouting volume for anchor cable grouting must exceed the theoretical grouting volume. Grouting is considered complete when the anchor vents no longer vent and the grout overflows from the vents.

[0046] S8. Anchor cable tensioning, locking and anchor sealing.

[0047] S801. The anchor cable 6 is tightly connected to the pile anchor coupling connection top plate 5, thereby achieving tensioning, locking and sealing of the anchor cable.

[0048] S9. Monitoring and testing.

[0049] After the corresponding steps of S901.S1-S8 are completed, the monitoring harness 7 is connected to the data acquisition device to obtain monitoring data of the prefabricated micropile body. At the same time, the construction quality of the prefabricated micropile and anchor cable is tested.

Claims

1. A prefabricated micropile with coupled force adjustment, monitoring and rapid assembly functions, characterized by: It comprises a prefabricated micro-pile pipe pile (1), a connecting steel base (2), connecting bolts (3), a pile sinking steel base (4), a pile-anchor coupling connecting top plate (5) and a monitoring harness (7); The prefabricated micropile pipe pile (1) is symmetrically welded with connecting steel seats (2) at both ends of the top and bottom, the bottom connecting steel seat (2) of the prefabricated micropile pipe pile (1) is connected to the sinking steel seat (4) via connecting bolts (3), and the top connecting steel seat (2) of the prefabricated micropile pipe pile (1) is connected to the pile anchor coupling connecting top plate (5) via connecting bolts (3); The prefabricated micro-pile pipe piles (1) are divided into low-strength pipe piles (1.1), medium-strength pipe piles (1.2) and high-strength pipe piles (1.3). The engineering geology and hydrogeology conditions of the slope or landslide can be obtained during the drilling process of the geological drilling rig. The strength of the prefabricated micro-pile at the corresponding distance above and below the deformation failure surface of the slope or landslide needs to be high-strength pipe piles (1.3), the strength of the rock-embedded section of the prefabricated micro-pile needs to be medium-strength pipe piles (1.2), and the strength of the section of the prefabricated micro-pile close to the slope surface needs to be low-strength pipe piles (1.1); the low-strength pipe piles are composed of pipe pile steel pipes (1.3.1), steel cages (1.3.2), monitoring harnesses (7), PVC pipes (1.3.3) and concrete (1.3.5). ); the medium-strength pipe pile is composed of a pipe pile steel pipe (1.3.1), a rod (1.3.4), a monitoring harness (7), a PVC pipe (1.3.3) and concrete (1.3.5); the high-strength pipe pile is composed of a pipe pile steel pipe (1.3.1), a steel cage (1.3.2), a rod (1.3.4), a monitoring harness (7), a PVC pipe (1.3.3) and concrete (1.3.5); the pipe pile steel pipe (1.3.1), the steel cage (1.3.2), the PVC pipe (1.3.3), the rod (1.3.4), the concrete (1.3.5) and the monitoring harness (7) on the cross section of the prefabricated micropile pipe pile (1) are all axially symmetrically distributed; The connecting steel seat is composed of a lower connecting steel plate (2.1), an upper connecting steel plate (2.2), a stiffening rib (2.3) and a grouting steel pipe (2.4).

2. A prefabricated micropile with coupled force allocation, monitoring and rapid assembly functions according to claim 1, characterized in that: A pipe pile grouting hole (1.4) is formed on each end of the connecting steel plate (2.2) connected to the pipe pile steel pipe (1.3.1) in the transverse axis direction.

3. The prefabricated micropile with coupled force allocation, monitoring and rapid assembly functions according to claim 1, characterized in that: Monitoring sensors (7.1) and monitoring sensor connecting lines (7.2) are symmetrically arranged inside the prefabricated micropile pipe pile (1).

4. The prefabricated micropile with coupled force allocation, monitoring and rapid assembly functions according to claim 1, characterized in that: The bottom of the pile-sinking steel seat (4) is welded with pile-sinking steel seat stiffening rib cones (4.1) distributed at right angles.

5. The prefabricated micropile with coupled force allocation, monitoring and rapid assembly functions according to claim 1, characterized in that: The top plate bolt holes (5.1), anchor cable connection holes (5.2) and top plate grouting holes (5.3) belonging to the pile-anchor coupling connection top plate (5) are distributed in an axisymmetric manner.

6. The prefabricated micropile with coupled force allocation, monitoring and rapid assembly functions according to claim 5, characterized in that: The top plate bolt hole (5.1) is in a curved elliptical shape, which can realize the angle adjustment between the pile-anchor coupling connection top plates (5).

7. A construction method for prefabricated micropiles coupled with force allocation, monitoring and rapid assembly functions as claimed in any one of claims 1 to 6, characterized in that: The process includes the following steps: S1. Material configuration, S2. Equipment configuration, S3. Site cleaning, S4. Hole forming and punching, S5. Prefabricated micro pile preparation, assembly and pile sinking, S6. Anchor cable installation, S7. Grouting, S8. Anchor cable tensioning, locking and anchor sealing, and S9. Monitoring and testing.

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