CN-122014264-A - Construction method of underground excavation channel of precipitation well

CN122014264ACN 122014264 ACN122014264 ACN 122014264ACN-122014264-A

Abstract

The invention discloses a construction method of a dewatering underground excavation channel, which belongs to the technical field of construction, and aims to improve the accuracy of the excavation position of a transverse channel door opening through measuring lofting construction, accurately ensure the error of an excavation outline through hole opening block construction, improve the accuracy of hole opening positioning and excavation, improve the stability of the hole opening through hole opening reinforcement construction, detect and strengthen a soil layer before transverse channel excavation, effectively reduce the occurrence of collapse of the soil layer, ensure the safety of transverse channel excavation, strengthen the support protection operation of the transverse channel, reduce the support force of the soil layer due to missing foreign matters when cutting and taking out the foreign matters, improve the safety of foreign matters treatment through channel backfilling construction and secondary pouring operation, and ensure that the pressure in a shield tunneling process is kept stable.

Inventors

ZHOU WUYI
DAI JUN
Shen Yangkui
PENG JINGFENG
XIE MINGKUN
ZHOU BO
CAO JUN
SU YINGYING
ZHANG PENGQI
LUO CHAO

Assignees

中铁城市发展投资集团有限公司
中铁八局集团有限公司
四川成德轨道交通有限公司

Dates

Publication Date: 20260512
Application Date: 20260316

Claims (10)

1. The construction method of the underground excavation channel for precipitation is characterized by comprising the following steps of: s1, measuring and lofting, namely measuring and lofting at one side of the bottom of a precipitation working well, measuring and lofting the position of a portal according to the elevation of the portal, and drawing an excavation contour line; s2, dividing the outline portal into sections, dividing the portal into eight sections, sequentially dividing the portal into sections, lifting the broken materials to a slag hopper, and transferring and cleaning; S3, reinforcing the hole, namely, after the hole is broken, reinforcing the hole by adopting a reinforcing mesh, sprayed concrete and a grid steel frame in time to prevent the hole from collapsing, and performing test assembly detection on the grid steel frame outside the hole in advance to measure the size and prevent overlarge deviation from the hole; S4, channel excavation supporting, namely detecting whether soil layers are required to be reinforced or not, excavating the channel by a positive step method, paving a grid steel frame, excavating an upper step, constructing an upper step primary supporting, excavating a lower step and constructing a lower step primary supporting; S5, supporting the channel, namely supporting the channel by erecting I-steel in the channel, so as to conveniently reinforce the channel, stably detect the channel after cutting and cleaning the foreign matters, and dismantling the I-steel later; s6, backfilling the working well channel, namely pouring a backfilled retaining wall at the opening, pouring the inside of the hole, and pouring and constructing the inside of the hole in two times to confirm the compactness of a backfilled area and ensure that the pressure is kept stable in the shield tunneling process.
2. The method for constructing a downcast underground excavation channel of a precipitation well as claimed in claim 1, wherein in the measuring and lofting construction, a measuring group measures the position of a hole gate according to the elevation of the hole gate, then the position of a central line is discharged, coordinate points are returned to two sides, and then an excavation contour line is drawn.
3. The construction method of the underground drainage channel is characterized in that in the construction of dividing and breaking the tunnel portal, the tunnel portal is divided and removed, the dimension errors of each block are controlled according to the order of dividing from left to right, and the connectivity of hoisting and reinforcing procedures after breaking is guaranteed.
4. The construction method of the underground excavation channel of the precipitation well of claim 1, wherein in the reinforcement construction of the opening, after the opening is broken, a glass fiber reinforced plastic net is adopted immediately, the whole section is arranged in a single layer, and concrete is sprayed, wherein a grid steel frame is arranged in the concrete; And the sprayed concrete is adopted for filling, so that the binding force between the sprayed concrete and surrounding rock mass is enhanced, and the structural stability of the opening after the opening is broken is ensured.
5. The method for constructing a precipitation underground excavation channel according to claim 4, wherein in the concrete spraying process, spraying operation is performed in sections and in pieces sequentially, the length of each section is not more than 6m, and spraying is performed in a sequence of wall-first arch-then arch-first and bottom-up; the spraying angle and the spraying distance are required to be controlled, so that the concrete is ensured to be uniformly and compactly covered on the reinforcing mesh and the grid steel frame, and after the sprayed concrete is finally solidified, water spraying maintenance is required to be carried out so as to ensure the strength growth and the durability of the concrete.
6. The construction method of the underground drainage channel of claim 5, wherein in the installation process of the grid steel frame, grid trial assembly work is required to be completed on site, all units are assembled according to a design drawing on the ground, inspection is performed after assembly is completed, and the underground drainage channel is assembled after inspection is qualified; the grid frame clings to surrounding rock, the arch foot is arranged on an undisturbed stratum, when the bottom surface is softer or the overdrawing occurs, a concrete cushion block is arranged in a cushioning mode, and 2 anchor pipes for locking the foot are arranged at the arch foot.
7. The construction method of the underground drainage channel of claim 1, wherein in the channel excavation construction, horizontal exploratory holes are formed in the holes, and core samples are taken out; if the soil body within the channel range is better in reinforcement condition and the stratum is more stable, reinforcement is not needed; If the soil body has poor self stability and large water content, the soil body is supplemented and grouting is carried out for reinforcement.
8. The method for constructing the underground excavation channel under the precipitation well of claim 1, wherein a layer of advanced grouting small guide pipe is arranged at the arch part before the excavation of the upper step in the process of excavating the upper step, the peripheral stratum is reinforced, the cyclic footage of the excavation of the upper step is controlled, and the excavation is carried out manually by using a pneumatic pick and a shovel; The upper step support comprises the construction procedures and methods of primary spraying concrete, hanging glass fiber reinforced plastic meshes, applying glass fiber positioning anchor rods, glass fiber grating frames and re-spraying concrete for wrapping, and the lower step support is constructed in the same way as the upper step.
9. The construction method of the underground drainage channel of claim 1, wherein the channel substrate is cleaned in the channel support construction, so that the substrate is smooth and firm, and no sundries and water are accumulated; laying a backing plate at the position of the I-steel footing, wherein the backing plate is flat and tightly attached to the substrate, and after the I-steel is in place, adopting a steel bar head to fix the I-steel footing with the periphery by spot welding to prevent displacement or overturning in the subsequent construction process; After foreign matters in the channel are cut and cleaned, monitoring data are combined when the I-steel is removed from the transverse channel, monitoring data including convergence, settlement and supporting structure stress such as steel frame stress, shotcrete crack and the like are analyzed after excavation is carried out on surrounding rock deformation, after the stability of the data is confirmed and the surrounding rock reaches a stable state, removing operation can be carried out, when the I-steel is removed, the vault I-steel is preferentially removed according to the principles of 'top-down, top-in-bottom and top-out-top-bottom', and then the side wall I-steel is gradually removed downwards, so that the instability of the surrounding rock caused by concentrated removal is avoided.
10. The construction method of the underground drainage underground excavation channel of claim 1, wherein in the construction of backfilling of the working well channel, concrete backfilling operation is carried out through a discharge opening of the working well, an outer retaining wall is poured firstly, inner concrete is poured after the retaining wall is initially set, and the construction of backfilling in a hole is carried out twice.

Description

Construction method of underground excavation channel of precipitation well Technical Field The invention belongs to the technical field of construction, and particularly relates to a construction method of a precipitation underground excavation channel. Background In the construction process of the shield machine, when the cross impact cone foreign matter appears in front of the shield machine to influence the advancing of the shield machine, the foreign matter needs to be taken out through the excavation transverse channel, and when the foreign matter is positioned below a bridge river channel, the foreign matter is interfered by river water, the excavation safety of the excavation transverse channel is directly influenced, the construction channel is matched with a dewatering well to work in order to meet the construction requirement of the excavation transverse channel, and the excavation channel is excavated from the bottom part of the dewatering well to the position of the foreign matter in front of the shield machine, so that the foreign matter is cleaned. However, when the conventional channel is provided with a portal at the bottom side of the precipitation well, the conditions of low breaking precision, large size deviation and unsmooth procedure connection are easy to occur, the foreign matter cleaning construction efficiency is affected, the stabilization of the transverse channel excavation is not facilitated, and therefore, the construction method for the precipitation well underground excavation channel is provided to solve the problems in the prior art. Disclosure of Invention The invention aims to provide a construction method of a precipitation underground excavation channel, which aims to solve the problems in the background technology. In order to achieve the above purpose, the invention adopts the following technical scheme: the construction method of underground excavation channel under precipitation well comprises measuring and lofting, namely measuring and lofting at one side of the bottom of the precipitation well, measuring and lofting the position of a portal according to the elevation of the portal, and drawing an excavation contour line; dividing the outline portal into eight blocks, sequentially dividing the portal into sections, lifting the broken materials to a slag hopper, and transferring and cleaning; reinforcing the hole, namely after the hole is broken, reinforcing the hole by adopting a reinforcing mesh, sprayed concrete and a grid steel frame in time to prevent the hole from collapsing, and testing and assembling the grid steel frame outside the hole in advance to measure the size and prevent overlarge deviation from the hole; The tunnel excavation supporting method comprises the steps of detecting soil layer stability before excavation, whether soil layer needs to be reinforced or not, excavating the interior of a tunnel through a positive step method, paving a grid steel frame, excavating an upper step, constructing an upper step primary supporting, excavating a lower step and constructing a lower step primary supporting; The channel support is carried out by erecting the I-steel in the channel, so that the channel is convenient to be reinforced, the channel stability after foreign matters are cut and cleaned is convenient to be detected, and the subsequent I-steel is removed; Backfilling a working well channel, namely pouring a backfilled retaining wall at the opening, pouring the inside of the hole, and pouring and constructing the inside of the hole in two times to confirm the compactness of a backfilled area and ensure that the pressure is kept stable in the shield tunneling process. Preferably, in the measuring and lofting construction, the measuring group measures the position of the hole gate according to the elevation of the hole gate, then the central line position is discharged, coordinate points are returned to two sides, and then the excavation contour line is drawn. Preferably, in the tunnel portal block breaking construction, the tunnel portal is removed in blocks, the size error of each block is controlled according to the sequence of the blocks from left to right, and the connectivity of hoisting and reinforcing procedures after breaking is ensured. Preferably, in the hole reinforcement construction, after the hole is broken, a glass fiber reinforced plastic net is immediately adopted, the whole section is arranged in a single layer, and concrete is sprayed, wherein a grid steel frame is arranged in the concrete; And the sprayed concrete is adopted for filling, so that the binding force between the sprayed concrete and surrounding rock mass is enhanced, and the structural stability of the opening after the opening is broken is ensured. Preferably, in the concrete spraying process, the spraying operation should be performed in sections and in pieces in sequence, the length of each section should not exceed 6m, and spraying is performed in the order of