A static pressure composite pile construction method

Abstract

The present application relates to a kind of static pressure composite pile construction methods, using static pressure composite pile construction equipment, including steel platform, blowout prevention and sealing device, static pressure pile machine, fixed anchor rod, first, steel platform is fixed on segment by fixed anchor rod, and counterforce is provided by tunnel structure;Then set blowout prevention and sealing device, finally static pressure pile machine is in position, and static pressure anchor rod pile is pressed in, and the purpose of governing tunnel continuous settlement is played.The present application can make pile head and tunnel structure form effective connection by side pile pressing, and do durability special handling, ensure stress and prevent and control long-term operation under the risk of leakage water;Through pile pressing, the purpose that original micro-disturbance grouting implementation effect is not good is solved, and pile body uses the high-strength design of steel bag concrete, can provide enough compression resistance;In construction process, special blowout prevention is set, to avoid construction process risk;Special static pressure anchor rod pile machine, adapt to the special working condition of tunnel long-distance transport.

Description

Technical Field

[0001] This invention relates to a static pressure pile construction equipment and method, and in particular to a static pressure pile construction equipment and method for settlement control in operating subway tunnels. Background Technology

[0002] During the long-term operation of the subway, due to various factors, especially geological conditions, significant subsidence has occurred in some sections, and the situation has remained unstable.

[0003] Static pressure anchor piles are commonly used for post-reinforcement of buildings. They have many advantages, such as being lightweight and having low requirements for construction conditions. In combination with the needs of subway settlement control, the prevention of water inrush risk during tunnel construction, the impact of reaction force on the tunnel, and the durability under long-term operation, the research and development background of this invention is to carry out targeted innovative applications of static pressure anchor piles to solve the above problems. Summary of the Invention

[0004] In view of the deficiencies in the prior art, the technical problem to be solved by the present invention is to provide a static pressure composite pile construction method for settlement control in operating subway tunnels.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a static pressure composite pile construction method, which uses static pressure composite pile construction equipment including a steel platform, a blowout prevention and sealing device, a static pressure pile driver, and fixed anchor bolts. First, the steel platform is fixed to the tunnel lining segments by fixed anchor bolts, and the tunnel structure provides the reaction force; then the blowout prevention and sealing device is set up; finally, the static pressure pile driver is positioned and the static pressure anchor bolt piles are driven in, so as to achieve the purpose of controlling the continuous settlement of the tunnel.

[0006] Furthermore, the static pressure anchor piles are installed on the side of the tunnel track bed. After construction, they are filled with stainless steel cover plates and grout to ensure the force transmission and long-term durability of the static pressure piles and avoid the risk of water inrush under long-term dynamic load and corrosion conditions.

[0007] Furthermore, the static pressure anchor pile is finally grouted to form a steel-clad concrete composite pile, which improves its compressive strength.

[0008] Furthermore, the upper part of the blowout prevention and sealing device is equipped with a flange. When leakage occurs in the pilot hole, it can be sealed and plugged by grouting through a groutable cap. During pile driving, a sealing gasket is installed between the flanges to prevent blowout.

[0009] Furthermore, the static pressure pile driver 3 adopts an assembly structure with a height of 1.8m, which is suitable for 1m long drill rods. The weight of a single component is less than 15kg, which is convenient for long-distance transportation in tunnels. It uses a single bidirectional 25T jack, which is suspended in the opposite direction on the crossbeam. The crossbeam is raised and lowered by a hand-operated hoist and is limited by side bolts.

[0010] The beneficial effects of this invention are:

[0011] This invention enables an effective connection between the pile head and the tunnel structure through side-pile driving, and provides special durability treatment to ensure stress resistance and prevent water leakage risks during long-term operation. It addresses the shortcomings of traditional micro-disturbance grouting by using pile driving, and the pile body employs a high-strength steel-clad concrete design to provide sufficient compressive strength. During construction, a special blowout prevention system is implemented to avoid construction risks. A specially designed static pressure anchor pile driver is suitable for the special working conditions of long-distance tunnel transportation. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the static pressure composite pile construction equipment and method of the present invention;

[0013] Figure 2 This is a schematic diagram of a groutable blowout prevention device;

[0014] Figure 3 This is a schematic diagram of the sealing device during pile driving. Detailed Implementation

[0015] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0016] like Figures 1 to 3 As shown, the present invention discloses a static pressure composite pile construction method for settlement control in subway tunnels, and the static pressure composite pile construction equipment includes a steel platform 1, a blowout prevention and sealing device 2, a static pressure pile driver 3, and fixed anchor bolts 4.

[0017] The steel platform 1 is fixed to the tunnel segment 5 by the fixed anchor rod 4, and the reaction force is provided by the tunnel structure; then the blowout prevention and sealing device 2 is installed, and finally the static pressure pile driver 3 is in place to press in the static pressure anchor piles, which achieves the purpose of controlling the continuous settlement of the tunnel.

[0018] Static pressure anchor piles are installed on the side of the tunnel track bed. After construction, they are filled with stainless steel cover plates and grout to ensure the force transmission and long-term durability of the static pressure piles and avoid the risk of water inrush under long-term dynamic load and corrosion conditions.

[0019] The static pressure anchor pile is finally filled with grout to form a steel-clad concrete composite pile, which improves its compressive strength.

[0020] The blowout preventer and sealing device 2 has a flange 7 installed on the upper part of the blowout preventer flange sleeve 6. When leakage occurs in the pilot hole, it is sealed and grouted by a specially made groutable cap 8. During pile driving, a sealing gasket 9 is installed between the flanges 7, and the sealing gasket 9 plays a role in preventing blowout.

[0021] The static pressure pile driver 3 adopts an assembly structure with a height of 1.8m, which is suitable for 1m long drill rods. The weight of a single component is less than 15kg, which is convenient for long-distance transportation in tunnels. It uses a single bidirectional 25T jack, which is suspended in the opposite direction on the crossbeam. The crossbeam is raised and lowered by a hand-operated hoist and is limited by the side bolts.

[0022] The specific construction method of this invention is as follows:

[0023] (1) First, cut the track bed and reserve the position for the steel platform;

[0024] (2) The steel platform 1 is in place. Drill holes into the segment 5 using an electric drill and insert anchor bolts 4 to fix the special steel platform 1.

[0025] (3) Then, core drilling is used to reach a certain depth of segment 5, sealing epoxy is applied to the outside of the outer sleeve, and it is embedded on the tunnel segment. The upper part is spot welded to the steel platform 1.

[0026] (4) Then, a small-diameter water drill is used to drill through the outer casing to remove tunnel segment 5;

[0027] (5) Then install the anti-spray and sealing device 2;

[0028] (6) Then the static pressure pile driver 3 and the static pressure drill rod are in place, and pile driving begins;

[0029] (7) After the pile is driven to the specified depth, the static pile driver 3 is moved and the steel platform 1 is dismantled;

[0030] (8) Perform core filling and grouting on the static pressure drill rod;

[0031] (9) Seal and pressure plate construction at the top of the pile;

[0032] (10) Restore the track bed.

[0033] The specific application of the construction method of the present invention is as follows:

[0034] First, 30cm of concrete on the side of the track bed is cut and chiseled away down to the inner arc surface of the tunnel segment. A precast steel platform is then placed in the tunnel, and holes are drilled at the reserved anchor points to insert bolts for fixing as reaction points for the static pressure device. A drilling rig passes through the reserved opening on the steel platform to create a hole, and a seamless steel pipe is embedded as the outer casing. The drilling rig then drills a hole inside the outer casing until it penetrates the tunnel structure. The static pressure device is then in place; the static pressure piles use seamless steel pipes with threaded connections and tapered ends. After reaching the designated depth, the steel platform is removed, and quick-setting grout is injected. The exposed outer casing and static pressure steel pipe on the tunnel segment are cut off, and a stainless steel cover plate is fixed to the segment to form an effective force transmission. The outer casing protrudes from the steel platform, and a flange with a specially designed cap is installed on the top. In the event of water inrush, the cap acts as a blowout preventer, providing favorable conditions for grouting. During static pressure, a sealing gasket is used to seal the outer casing and the pile pipe. This invention is applicable to the settlement treatment of operating tunnels in soft soil areas.

Claims

1. A method for constructing a static pressure composite pile, characterized in that: The static pressure composite pile construction equipment adopted includes a steel platform, a blowout prevention and sealing device, a static pressure pile machine, and fixed anchor rods. First, the steel platform is fixed on the tube piece through the fixed anchor rods, and the counterforce is provided by the tunnel structure. Then, the blowout prevention and sealing device is set, and the outer sleeve of the blowout prevention and sealing device is embedded on the tunnel tube piece and is point-welded with the upper part of the steel platform. The outer sleeve is exposed to the steel platform, and a flange plate is arranged on the upper part of the outer sleeve. When leakage occurs in the lead hole, the grouting cover is used for sealing and grouting. When the pile is pressed, sealing pads are arranged between the flange plates to prevent blowout. Finally, the static pressure pile machine is positioned, and the static pressure anchor rod pile is pressed in to control the continuous settlement of the tunnel. The static pressure anchor rod pile is arranged on the side of the tunnel bed, and after the construction is completed, the stainless steel cover plate and the grouting material are filled to ensure the force transmission and long-term durability of the static pressure pile and to avoid the risk of water gushing under the conditions of long-term dynamic load and corrosion. The static pressure pile machine adopts a spliced structure, the height is 1.8 m, it is suitable for a 1-m-long drill rod, and the weight of a single component is less than 15 kg, which facilitates long-distance transportation in the tunnel. A single bidirectional 25T jack is hung on the cross beam in the opposite direction, the cross beam is lifted up and down through a hand-operated hoist, and the side hole bolt is used for limiting.

2. The method according to claim 1, wherein: The static pressure anchor rod pile is finally grouted and filled with a core to form a steel bag concrete composite pile, and the compressive performance is improved.

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