Construction method of overhaul well in pipe jacking well

Abstract

The invention discloses a construction method for an overhaul well in a pipe-jacking well. The construction method comprises the steps that a concrete bottom plate is poured at the bottom of the pipe-jacking well; an overhaul well is constructed on the concrete bottom plate until the lowest layer of diagonal bracings are reached, and the adjacent pipe jacking pipe joints are communicated through the overhaul well; a plurality of plastic drainage plates are arranged between the pipe jacking well and the overhaul well at intervals, and one end of each plastic drainage plate extends out of the pipe jacking well and is connected with drainage equipment; soil body backfilling is conducted in the gap between the pipe jacking well and the overhaul well, and the height of backfilled soil is not larger than that of the overhaul well; water is added into the backfill soil, meanwhile, drainage equipment is started to pump water from the backfill soil, and the water pumping speed is made to be larger than the water adding speed till the backfill soil is solidified; the diagonal bracings on the lowermost layer are dismantled, and the overhaul well continues to be constructed upwards till the diagonal bracings on the upper layer are reached; and the steps are repeated till construction of the overhaul well is completed, and the stability of the foundation pit is improved through the construction method.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and particularly relates to a construction method for an inspection well in a jacking pipe well. Background Art

[0002] During long-span jacking pipe construction, an inspection well needs to be set at certain intervals to truncate the long-span jacking pipe into multiple jacking pipe sections. After problems occur in the subsequent pipeline, construction workers can descend into the pipeline through the inspection well at the corresponding position for repair and maintenance. Before constructing the inspection well, it is necessary to excavate the jacking pipe well until the construction position of the pipeline, and then carry out foundation pit support in the jacking pipe well. After connecting the adjacent jacking pipe sections to the jacking pipe well from opposite sides of the jacking pipe well, construct the inspection well at the bottom of the jacking pipe well and connect the adjacent jacking pipe sections. However, since the inspection well needs to be constructed upward until it is flush with the jacking pipe well and has a high height, the inspection well will conflict with the support structure in the jacking pipe well. The traditional construction method is to demolish the support structure and then construct the inspection well. However, due to the long construction period of the inspection well, after the support structure is demolished, the jacking pipe well is in an unprotected state for a long time, and there is a risk of collapse of the jacking pipe well during the construction process of the inspection well, posing a safety hazard. Summary of the Invention

[0003] The purpose of the present invention is to overcome the defects of the prior art and provide a construction method for an inspection well in a jacking pipe well. By adding water and draining water in the backfill soil, the pore water pressure in the backfill soil is reduced, and the settlement consolidation of the backfill soil is accelerated, ensuring the stability of the foundation pit.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is a construction method for an inspection well in a jacking pipe well, including the steps:

[0005] Step 1: After multi-layer cross bracing support in the jacking pipe well is completed, pour a concrete floor slab at the bottom of the jacking pipe well;

[0006] Step 2: Construct the inspection well at the designed position of the inspection well on the concrete floor slab until the lowest cross bracing, so that the inspection well connects the adjacent jacking pipe sections;

[0007] Step 3: Intermittently arrange a plurality of plastic drainage boards in the gap between the jacking pipe well and the inspection well, so that one end of each plastic drainage board extends to the concrete floor slab, and the other end extends out of the jacking pipe well and is connected to drainage equipment;

[0008] Step 4: Backfill the soil in the gap between the jacking pipe well and the inspection well, so that the height of the backfill soil is not higher than the inspection well;

[0009] Step 5: Add water to the backfill soil, and at the same time start the drainage equipment to pump water from the backfill soil, so that the pumping speed is greater than the water adding speed until the backfill soil consolidates;

[0010] Step 6: Demolish the lowest cross bracing and continue to construct the inspection well upwards until the upper cross bracing is reached.

[0011] Step 7: Repeat the above Steps 4 to 6 until the construction of the inspection well is completed and all the backfill soil is consolidated.

[0012] A further improvement of the construction method of the inspection well in the pipe jacking well of the present invention lies in that after performing the above Step 7, grouting is carried out into each of the plastic drainage boards.

[0013] A further improvement of the construction method of the inspection well in the pipe jacking well of the present invention lies in that when performing the above Step 2, during the construction of the inspection well, the adjacent pipe jacking pipe joints are respectively embedded on the opposite sides of the inspection well, so that the pipe orifices of each pipe jacking pipe joint are flush with the inner wall of the inspection well.

[0014] A further improvement of the construction method of the inspection well in the pipe jacking well of the present invention lies in that a ladder for people to go up and down is vertically and continuously connected to the inner wall of the inspection well.

[0015] Compared with the prior art, the advantages of the present invention are as follows:

[0016] By injecting water into the backfill soil and pumping water at the same time, and making the pumping speed greater than the injection speed, the pore water pressure in the backfill soil is reduced, the settlement consolidation of the backfill soil is accelerated, and the stability of the foundation pit is ensured. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0018] Figure 1 It is a top view of the pipe jacking well of the construction method of the inspection well in the pipe jacking well of the present invention.

[0019] Figure 2 It is a schematic diagram of the connection between the inspection well and the adjacent pipe jacking pipe joints of the construction method of the inspection well in the pipe jacking well of the present invention.

[0020] Figure 3 It is a schematic diagram of the soil backfill of the construction method of the inspection well in the pipe jacking well of the present invention.

[0021] Figure 4 It is a schematic diagram of the segmented construction of the inspection well of the construction method of the inspection well in the pipe jacking well of the present invention.

[0022] Figure 5Schematic diagram showing the completion of the construction of the inspection well in the pipe jacking well of the present invention.

[0023] Figure 6 Schematic diagram showing the completion of the consolidation of the backfill soil in the pipe jacking well of the construction method of the inspection well of the present invention.

[0024] In the figure: 1. Pipe jacking well; 2. Pipe jacking pipe section; 3. Cast-in-place pile; 4. Three-axis mixing pile; 5. Concrete floor slab; 6. Inspection well; 7. Opposing brace; 8. Backfill soil; 9. Plastic drainage board; 10. Drainage equipment. Detailed implementation manners

[0025] The following describes the implementation manners of the present invention through specific examples. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific implementation manners. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] The following further describes in detail the construction method of the inspection well in the pipe jacking well of the present invention in conjunction with the accompanying drawings and specific embodiments.

[0027] Please refer to Figures 1 to 6 As shown, the construction method of the inspection well in the pipe jacking well includes the following steps:

[0028] Step 1: After the multi-layer opposing braces 7 in the pipe jacking well 1 are supported, a concrete floor slab 5 is poured at the bottom of the pipe jacking well 1;

[0029] By constructing the concrete floor slab 5 at the bottom of the pipe jacking well 1, a construction foundation is provided for the inspection well 6, and at the same time, it is avoided that water seeps to the bottom when water is added to the backfill soil 8 subsequently.

[0030] Step 2: The inspection well 6 is constructed at the designed position of the inspection well 6 on the concrete floor slab 5 until the lowermost opposing brace 7, so that the inspection well 6 connects the adjacent pipe jacking pipe sections 2;

[0031] Step 3: A plurality of plastic drainage boards 9 are arranged at intervals in the gap between the pipe jacking well 1 and the inspection well 6, so that one end of each plastic drainage board 9 extends to the concrete floor slab 5, and the other end extends out of the pipe jacking well 1 and is connected to the drainage equipment 10;

[0032] Step 4: The gap between the pipe jacking well 1 and the inspection well 6 is backfilled with soil, so that the height of the backfill soil 8 is not higher than that of the inspection well 6;

[0033] Step 5: Water is added to the backfill soil 8, and at the same time, the drainage equipment 10 is started to pump the backfill soil 8, so that the pumping speed is greater than the water addition speed until the backfill soil 8 is consolidated;

[0034] Step 6: Demolish the lowest cross brace 7, and continue to construct the inspection well 6 upward until the upper cross brace 7 is reached.

[0035] Step 7: Repeat the above Steps 4 to 6 until the construction of the inspection well 6 is completed and all the backfill soil 8 is consolidated.

[0036] Specifically, a ring of cast-in-place piles 3 is constructed on the outer periphery of the pipe jacking well 1, and a ring of triaxial mixing piles 4 is also constructed on the outer periphery of the ring of cast-in-place piles 3. Both the cast-in-place piles 3 and the triaxial mixing piles 4 extend below the bottom elevation of the pipe jacking well 1, and grouting reinforcement is required between the ring of triaxial mixing piles 4 and the ring of cast-in-place piles 3.

[0037] By constructing the cast-in-place piles 3 and the triaxial mixing piles 4 on the outer periphery of the pipe jacking well 1, the waterproof effect of the pipe jacking well 1 is ensured, preventing the soil outside the pipe jacking well 1 from seeping into the pipe jacking well 1. At the same time, when adding water to the backfill soil 8 subsequently, it prevents water from leaking to the periphery of the pipe jacking well 1.

[0038] Preferably, after performing the above Step 7, grouting is carried out into each plastic drainage board 9.

[0039] By grouting into the plastic drainage board 9, the backfill soil 8 is further compacted, further improving the stability of the foundation pit.

[0040] Preferably, when performing the above Step 2, during the construction of the inspection well 6, the adjacent pipe jacking pipe sections 2 are respectively embedded on the opposite sides of the inspection well 6, making the pipe orifice of each pipe jacking pipe section 2 flush with the inner wall of the inspection well 6.

[0041] Specifically, the aperture of the pipe jacking pipe section 2 is not less than 1.5 m, allowing construction personnel to enter the pipe jacking pipe section 2 through the pipe orifice for maintenance.

[0042] Specifically, during the construction of the inspection well 6, the steel bars of the inspection well 6 are first tied, and through holes for the pipe jacking pipe sections 2 to pass through are reserved during the steel bar tying. During the subsequent formwork support and pouring, the pipe jacking pipe sections 2 are poured inside.

[0043] Preferably, a ladder for people to go up and down is vertically and continuously connected to the inner wall of the inspection well 6.

[0044] By providing the ladder, it is convenient for construction personnel to go down into the inspection well 6 to inspect the pipe jacking pipe section 2.

[0045] Specifically, the top of the inspection well 6 is detachably connected with a manhole cover.

[0046] When the pipe jacking needs to be inspected, first cut off the water in the pipe jacking, and then the construction personnel open the manhole cover and go down into the inspection well 6 through the ladder to inspect the pipe jacking.

[0047] Specifically, the inspection well 6 includes a connecting section for connecting adjacent jacking pipe sections 2 and an extending section for people to go up and down. The connecting section is located below the extending section and is connected to each other. The diameter of the connecting section is larger than that of the extending section. The ladder is connected to the inner wall of the extending section and extends downward until it is connected to the concrete floor slab 5.

[0048] By providing the extending section and restricting the diameter of the extending section to be smaller than that of the connecting section, the consumption of construction materials for the inspection well 6 is reduced and the cost is saved.

[0049] It should be noted that the structures, ratios, sizes, etc. shown in the drawings of this specification are only used to cooperate with the content disclosed in the specification for those who are familiar with this technology to understand and read, and are not used to limit the conditions under which the present invention can be implemented. Therefore, they do not have any technical substance. Any modification of the structure, change of the proportional relationship or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope that can be covered by the technical content disclosed in the present invention. At the same time, the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of clear description and are not used to limit the scope of implementation of the present invention. The change or adjustment of their relative relationships, without substantial change in technical content, should also be regarded as the scope of implementation of the present invention.

[0050] The above are only the preferred embodiments of the present invention, and do not impose any form of limitation on the present invention. Although the present invention has been disclosed above with the preferred embodiments, it is not used to limit the present invention. Any person skilled in the art, without departing from the technical solution of the present invention, can make some changes or modifications to the above-disclosed technical content to be equivalent change equivalent embodiments. However, as long as it does not depart from the technical content of the present invention, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A construction method for a maintenance well in a pipe jacking well, characterized in that: Includes steps: Step 1: After the multi-layer bracing support in the jacking pipe well is completed, a concrete bottom plate is poured at the bottom of the jacking pipe well; Step 2: constructing the inspection well at the designed position of the inspection well on the concrete bottom plate until the lowest support, so that the inspection well connects the adjacent top pipe sections; Step 3: multiple plastic drain boards are arranged in the gap between the pipe jacking well and the inspection well, so that one end of each plastic drain board extends to the concrete bottom plate, and the other end extends out of the pipe jacking well and is connected to the drainage equipment; Step 4: backfilling the gap between the jacking well and the inspection well so that the height of the backfilled soil is not higher than that of the inspection well; Step 5: adding water to the backfill soil, and starting the drainage equipment to pump water from the backfill soil at the same time, so that the pumping speed is greater than the water adding speed, until the backfill soil is consolidated; Step 6: Remove the bottommost support and continue to construct the inspection well upward until the upper support; Step 7: Repeat the above steps 4 to 6 until the construction of the inspection well is completed and the backfill soil is completely consolidated.

2. The construction method of the inspection well in the jacking well as claimed in claim 1, characterized in that: After executing the above step 7, grouting is performed into each of the plastic drainage boards.

3. The construction method of the inspection well in the jacking well as claimed in claim 1, characterized in that: When executing the above step 2, during the construction of the inspection well, adjacent jacking pipe sections are pre-buried on opposite sides of the inspection well, so that the pipe opening of each jacking pipe section is flush with the inner wall of the inspection well.

4. The construction method of the inspection well in the jacking well as claimed in claim 1, characterized in that: A ladder for people to go up and down is vertically connected to the inner wall of the inspection well.

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