Gravity flow pipe-jacking tunnel water passing construction method based on pipe-jacking shell abandoning process

Abstract

The invention relates to a gravity flow pipe-jacking tunnel water flow construction method based on a pipe-jacking shell abandoning process, which comprises the following steps: analyzing the geological condition of a pipe-jacking shell abandoning section according to a design file and a geological survey result, and carrying out foundation reinforcement on the area of the shell abandoning section; the pipe jacking machine carries the pipe jacking pipe joint to be jacked into the designed position from the starting well, then equipment in the pipe jacking machine is dismantled and moved out of the starting well, and then in-shell cast-in-situ structure construction is conducted in a machine shell of the pipe jacking machine; constructing a horse-riding well structure above the pipe jacking section, connecting the well bottom of the horse-riding well structure with the top of the pipe jacking section behind the pipe jacking machine shell, pouring concrete at the joint of the horse-riding well structure and the pipe jacking section for sealing, and then forming a hole in the top of the pipe jacking section to be communicated with the horse-riding well structure; a wall is built between the pipe jacking section and the pipe jacking machine shell to seal a pipeline between the pipe jacking section and the pipe jacking machine shell. The construction method has the advantages that the gravity flow pipe jacking pipeline construction which is simple in process and small in influence on the surrounding environment can be achieved, and water passing of the gravity flow pipe jacking tunnel is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of tunnel construction, in particular to a gravity flow pipe jacking tunnel water-passing construction method based on a pipe jacking shell abandonment process. Background Art

[0002] In the construction of urban gravity flow pipe jacking tunnels, pipe jacking is a commonly used construction technology. Pipe jacking construction is to set up a working well and a receiving well foundation pit, lift the pipe jacking machine, pipe sections and jacks into the working well foundation pit for initial jacking, push them into the receiving well under the action of the main jacking jack and the relay room, lift the pipe jacking machine out, and realize the connection from the working well to the receiving well.

[0003] With the continuous deepening of urbanization, the shallow underground space in cities is gradually saturated, and the demand for the development of medium and deep underground space is increasing. The implementation of gravity flow pipe jacking tunnels in medium and deep underground spaces often requires the establishment of deeper pipe jacking starting wells and receiving wells. The construction of these starting wells and receiving wells often requires the occupation of a large area of ​​construction site, which has an adverse impact on the normal operation of surrounding urban facilities. In extreme cases, the pipe jacking starting and receiving wells may even be unable to be implemented due to restrictions on surrounding conditions.

[0004] As the global average temperature continues to rise, various meteorological disasters occur more frequently every year, and building a "resilient city" has gradually become a compulsory course for urban development. The construction of gravity flow drainage tunnels as a means of dealing with extreme weather often requires the pipe network system to have good water flow conditions.

[0005] In order to deal with the problem that the jacking receiving well cannot be implemented, in the existing technology, people will use methods such as jacking shell abandonment to deliver the jacking pipe to the designed position to achieve underground pipe connection, but it is still difficult to achieve water flow conditions in the pipeline. Summary of the invention

[0006] The purpose of the present invention is to provide a gravity flow jacking tunnel water supply construction method based on the jacking shell abandonment process according to the above-mentioned deficiencies of the prior art. The jacking pipe is delivered to the designed position in the jacking shell abandonment process, and a method of constructing a riding well connecting pipeline on the ground is used to achieve water supply conditions, thereby eliminating the jacking pipe receiving well of the traditional jacking gravity flow pipeline, reducing the project cost and construction period. At the same time, the use of cast-in-place structure in the jacking pipe shell, pouring concrete at the connection between the jacking pipe and the riding well for sealing, etc., ensures the stability of the overall structure, reduces the impact on the surrounding environment, and reduces the construction risk.

[0007] The purpose of the present invention is achieved by the following technical solutions: A gravity flow jacking tunnel water construction method based on the jacking shell abandonment process is characterized by: comprising an abandoned jacking machine casing, a jacking pipe section and a riding well structure, wherein the jacking machine casing and the jacking pipe section are fixedly connected and the interiors of the two are connected, and the riding well structure is arranged above the jacking pipe section and the interiors of the two are connected.

[0008] The casing of the pipe jacking machine and the pipe jacking sections are connected and fixed via a cast-in-place structure inside the casing to form an integral structure.

[0009] The cast-in-place structure in the shell includes circumferential reinforcement steel bars, longitudinal reinforcement steel bars, and L-shaped connecting bars. The circumferential reinforcement steel bars are arranged circumferentially along the casing of the pipe jacking machine, and the longitudinal reinforcement steel bars are arranged longitudinally along the casing of the pipe jacking machine. The L-shaped connecting bars are used to connect the circumferential reinforcement steel bars and the longitudinal reinforcement steel bars. After each steel bar is cast through formwork, the cast-in-place structure of the shell is formed.

[0010] The shell cast-in-place structure and the top pipe section are connected by embedded reinforcement.

[0011] The riding well structure includes a prefabricated riding well shaft, a riding well enclosure and a steel sleeve, wherein the steel sleeve is arranged inside the riding well enclosure, and the prefabricated riding well shaft is arranged inside the steel sleeve and is connected with the top pipe section.

[0012] Concrete is poured and sealed at the connection between the prefabricated shaft of the riding well and the jacking pipe section.

[0013] The casing of the pipe jacking machine and parts of the pipe jacking section are both arranged in the foundation reinforcement body, and the connection between the two is located within the range of the foundation reinforcement body.

[0014] The connection port between the casing of the pipe jacking machine and the pipe jacking section is provided with a waterproof part.

[0015] Bricks and foamed concrete are used to build walls at the pipeline positions between the casing of the pipe jacking machine and the pipe jacking pipe sections.

[0016] The advantages of the present invention are: (1) It provides a feasible solution for gravity flow pipe jacking tunnel construction in densely populated urban areas where the pipe jacking receiving well is not available. The pipe jacking receiving well is eliminated. After the pipe jacking arrives at the receiving location, the outer shell structure of the pipe jacking machine is abandoned as a whole. The pipe jacking pipeline is connected to the riding well to achieve water flow conditions, which directly reduces the project investment and construction period, and can save a lot of resources for society. (2) The foundation of the surrounding soil is reinforced in the receiving section of the jacking pipe, which improves the self-supporting ability of the soil and plays a certain role in water isolation. At the same time, the cast-in-place structure in the jacking pipe casing is connected to the jacking pipe casing by L-shaped steel bars. At the same time, the formwork is reinforced with circumferential and longitudinal steel bars to ensure the overall stability, reduce the impact on the surrounding environment, and reduce construction risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A longitudinal sectional view of the first step of construction of the present invention; Figure 2 It is a longitudinal section view of the second step of the construction of the present invention; Figure 3 It is a longitudinal section view of the third step of the construction of the present invention; Figure 4 It is a longitudinal section view of the fourth and fifth steps of the construction of the present invention; Figure 5 It is a longitudinal section view of the sixth step of the construction of the present invention; Figure 6 This is a cross-sectional view of the cast-in-place structure construction in the shell in the third step of the construction of the present invention. DETAILED DESCRIPTION

[0018] The features of the present invention and other related features are further described in detail below through embodiments in conjunction with the accompanying drawings to facilitate understanding by those skilled in the art: like Figure 1-6 As shown, marks 1-15 in the figure respectively represent: foundation reinforcement body 1, pipe jacking machine cutter head 2, pipe jacking machine casing 3, equipment inside the pipe jacking machine 4, connection port 5, pipe jacking pipe section 6, cast-in-place structure inside the casing 7, riding well enclosure 8, riding well steel sleeve 9, riding well prefabricated shaft 10, concrete seal 11, L-shaped steel bar 12, cast-in-place structure formwork 13, circumferential reinforcement steel bar 14, and longitudinal reinforcement steel bar 15.

[0019] Example: Combination Figures 1 to 6 As shown, the gravity flow jacking tunnel construction structure based on the jacking and shell abandonment process in this embodiment includes the following construction methods: Step 1: If Figure 1 As shown, according to the design documents, geological survey results and the investigation of the surrounding environment of the Qimajing, the appropriate foundation reinforcement method, construction parameters, Qimajing depth, Qimajing enclosure, etc. are determined, and an appropriate construction method, such as the MJS construction method, is used to construct the foundation reinforcement body 1 in the area where the shell abandonment section is located.

[0020] Step 2: If Figure 2As shown, the pipe section 6 is pushed from the starting well to the designed receiving position, and then the pipe jacking machine internal equipment 4 located in the pipe jacking machine casing 3 is removed; the pipe jacking machine casing 3 has a pipe jacking machine cutter head 2 in the forward direction. A stiffening plate is welded on the top of the pipe jacking machine casing 3, and a hand chain hoist is fixed on the stiffening plate hoisting hole. The pipe jacking machine equipment 4 is removed in turn by the hand chain hoist, and then other steel structures in the pipe jacking machine such as the breast plate are cut off, and then transported to the starting well with a flatbed truck for hoisting.

[0021] Step 3: If Figure 3 As shown, the construction of the cast-in-shell structure is as follows: first, the circumferential reinforcement steel bars 14 of the cast-in-shell structure are positioned in the casing 3 of the pipe jacking machine, and then the longitudinal reinforcement steel bars 15 are tied and the L-shaped connecting bars 12 are welded. Then the cast-in-place structure formwork 13 is installed, and the circumferential reinforcement steel bars 14 and the longitudinal reinforcement steel bars 15 are installed at the same time. Concrete is poured from bottom to top, and the cast-in-shell structure is connected to the pipe jacking section 6 by embedded reinforcement.

[0022] Step 4: If Figure 4 As shown, the horse-riding well structure is constructed: the center of the horse-riding well is verified with a total station, the steel sleeve 9 of the horse-riding well is lowered using a pipe shaking machine, and then the high-pressure rotary jet piles of the horse-riding well retaining structure 8 are constructed. After the retaining construction is completed, soil is taken from the steel sleeve 9 of the horse-riding well.

[0023] Step 5: Weld the riding well steel sleeve 9 and the top pipe segment 6 steel bars, then lower the riding well prefabricated shaft 10, weld the riding well prefabricated shaft 10 and the top pipe segment 6 steel bars, and pour concrete seal 11 around the connection between the shaft 10 and the top pipe segment. After the riding well structure construction is completed, open a hole at the top of the top pipe segment 6.

[0024] Step 6: If Figure 5 As shown, bricks + foamed concrete are used to build a wall to close the pipeline between the jacking pipe section 6 and the jacking machine casing 3.

[0025] In the specific implementation of this embodiment: in step 1 of this embodiment, the MJS foundation reinforcement range is 1m outside the tunnel wall, wherein the reinforcement range below the tunnel is 4m outside the pipe to ensure the bearing capacity of the soil below.

[0026] Before the jacking pipe reaches the reinforcement area, recheck the data such as the jacking pipe measurement control point, jacking pipe axis, jacking mileage, jacking pipe posture, etc. At the same time, control the jacking speed when entering the foundation reinforcement area to prevent the abnormal increase of soil pressure caused by excessive jacking speed, thereby causing the overall displacement of the MJS method pile to destroy the reinforcement effect.

[0027] When the pipe jacking machine enters the reinforcement area, the reinforced soil in front of the pipe jacking machine cutter head 2 can be improved to ensure the normal circulation of the reinforced soil, so that the soil pressure is controlled within the normal range. The soil pressure changes should be closely monitored before the final shutdown.

[0028] In step 4 of this embodiment, the connection port 5 between the jacking pipe casing 3 and the jacking pipe section 6 can be waterproofed by using a water-swellable rubber water retaining strip, an EPDM rubber elastic sealing pad, etc.

[0029] The tools used in the above steps are as follows: a. Pipe jacking construction equipment: including pipe jacking machine and its supporting equipment, prefabricated pipe sections, main jacking cylinder of jacking device, jack, supporting hydraulic equipment and relay room.

[0030] b. Structural construction equipment: including electric welders, cutting machines, grouting machines, and electric drills, mainly used for welding steel bars, cutting steel bars, pouring concrete, and chiseling out structural steel bars, etc.

[0031] c. Horse well construction equipment: including using a pipe shaking machine to lower the steel sleeve, an excavator to take soil, and a crane to lower the prefabricated wellbore.

[0032] d. Construction measurement equipment: including total station, level, tilt sensor and other instruments for measuring the posture of the tunnel structure being advanced and verifying the position of the riding shaft.

[0033] This embodiment achieves water flow conditions by delivering the jacking pipe to the designed position in the jacking pipe abandonment process and constructing a horse well connecting pipeline on the ground, eliminating the jacking pipe receiving well of the traditional jacking pipe gravity flow pipeline, reducing the project cost and construction period. At the same time, the use of cast-in-place structure in the jacking pipe shell and pouring concrete to seal the connection between the jacking pipe and the horse well ensures the stability of the overall structure, reduces the impact on the surrounding environment, and reduces construction risks.

[0034] Before the pipe jacking machine reaches the designed shell abandonment position, the foundation should be reinforced according to the geological conditions and surrounding environment of the shell abandonment section. The foundation reinforcement can also be carried out by cement reinforcement, freezing reinforcement, precipitation reinforcement and other methods.

[0035] The final shutdown and shell abandonment position of the pipe jacking machine is in the foundation reinforcement area, and the pipe jacking machine casing 3 is retained in the original position. Subsequent equipment dismantling and cast-in-place structure construction are all carried out in the pipe jacking machine casing.

[0036] The pipe jacking construction methods include earth pressure balance, mud water balance, composite type, manual excavation and other pipe jacking construction methods.

[0037] The cross section of the top pipe segment 6 can be circular, rectangular or the like according to design requirements.

[0038] The cast-in-place structure of the shell in the casing 3 of the pipe jacking machine is used as a permanent lining and adopts a reinforced concrete structure. At the same time, it can be connected with the rear pipe section of the pipe jacking machine by means of embedded reinforcement or the like.

[0039] Although the above embodiments have described in detail the concepts and embodiments of the present invention with reference to the accompanying drawings, ordinary technicians in this field can recognize that various improvements and changes can still be made to the present invention without departing from the scope of the claims, so they are not described one by one here.

Claims

1. A gravity flow pipe jacking tunnel water supply construction method based on pipe jacking and shell abandonment technology, characterized in that: The construction method comprises the following steps: According to the design documents and geological survey results, the geological conditions of the abandoned shell section of the jacking pipe are analyzed, and the foundation of the abandoned shell section is reinforced; The pipe jacking machine carries the pipe section from the starting well to the designed position, then removes the equipment inside the pipe jacking machine and moves it out of the starting well, and then carries out the cast-in-place structure construction inside the casing of the pipe jacking machine; A riding well structure is constructed above the jacking pipe section, the bottom of the riding well structure is connected to the top of the jacking pipe section behind the casing of the jacking machine, concrete is poured and sealed at the connection between the riding well structure and the jacking pipe section, and then a hole is opened at the top of the jacking pipe section to communicate with the riding well structure; A wall is built between the pipe jacking section and the casing of the pipe jacking machine to seal the pipeline therebetween.

2. A gravity flow pipe jacking tunnel water supply construction method based on pipe jacking and shell abandonment technology according to claim 1, characterized in that: Circumferential reinforcement steel bars and longitudinal reinforcement steel bars are constructed in the casing of the pipe jacking machine, and the circular reinforcement steel bars and the longitudinal reinforcement steel bars are connected by shaped connecting bars, and concrete is poured to form the cast-in-place structure of the casing.

3. A gravity flow pipe jacking tunnel water supply construction method based on pipe jacking and shell abandonment technology according to claim 1 or 2, characterized in that: The shell cast-in-place structure is connected to the jacking pipe section at the rear section of the jacking machine casing by adopting embedded reinforcement.

4. A gravity flow pipe jacking tunnel water supply construction method based on pipe jacking and shell abandonment technology according to claim 1, characterized in that: A pipe shaking machine is used to lower the steel sleeve of the riding well, and then the riding well enclosure structure is constructed. After the enclosure construction is completed, soil is taken from the steel sleeve of the riding well; then the prefabricated shaft of the riding well is lowered into the steel sleeve of the riding well, the prefabricated shaft of the riding well is welded to the steel bars of the jacking pipe section, and concrete is poured around the connection between the prefabricated shaft of the riding well and the jacking pipe section to seal it. After the construction of the riding well structure is completed, a hole is opened at the top of the jacking pipe section 6.

Images