CN-121976807-A - Active control and collaborative supporting construction method for inclined shaft open channel-dark cave junction section

CN121976807ACN 121976807 ACN121976807 ACN 121976807ACN-121976807-A

Abstract

The invention discloses an active control and collaborative support construction method for an inclined shaft open channel-dark cave junction section, and belongs to the technical field of mine and tunnel engineering construction. The method sequentially comprises the following steps of performing guniting protection on open trench excavation and upward slope to form a surface stress closed shell, constructing a forepoling shed at the arch part of a dark cave and performing grouting to form a deep pressure-bearing arch and a composite stress shell, performing mechanized excavation under the protection of a composite pre-support system, immediately erecting a U-shaped steel contractible support as a temporary support, constructing a reinforced concrete permanent well wall at the inner side of the temporary support, and finally performing grouting backfilling reinforcement after the wall to form a full-ring closed three-dimensional waterproof and drainage system. The core of the invention is to construct a loop-to-loop active control and cooperative support system, and through the temporary and permanent support conversion of composite pre-support, yielding and compression resistance combination and three-dimensional waterproof, the invention effectively solves the industrial problems of poor stability, easy collapse and easy water seepage of surrounding rocks at the bright-dark junction section, and obviously improves the construction safety and engineering quality.

Inventors

ZHANG YING
ZHANG TENGFEI
ZHANG YONG
SONG WEI
ZHU QIBIN
SONG ZIFENG
LI SHUXUAN
LIU PENGHUI
WU HAO
LI AO

Assignees

郑州绿智工程设计有限公司
煤炭工业太原设计研究院集团有限公司
河南宏基煤业有限公司

Dates

Publication Date: 20260505
Application Date: 20251230

Claims (10)

1. The active control and cooperative support construction method for the inclined shaft open channel-dark cave junction section is characterized by comprising the following sequential steps: S1, performing guniting protection on an upward slope excavated by an open trench to form a surface stress closed shell; S2, constructing an advanced pipe shed at the arch part of the excavated contour line designed in the hidden cave, and grouting to form a deep pressure-bearing arch and a composite stress shell; s3, mechanically excavating under the protection of the composite pre-support system, and immediately erecting a U-shaped steel contractible support as temporary support after excavating; s4, constructing a reinforced concrete permanent well wall on the inner side of the temporary support; s5, grouting backfilling and reinforcing are carried out on the back of the permanent well wall through the pre-buried grouting pipe, and the full-ring closed three-dimensional waterproof and drainage system is formed.
2. The method according to claim 1, wherein in step S2, the grouting parameters of the advance pipe shed are dynamically adjusted according to the rock mass breaking degree, and the single-hole grouting amount Q is estimated by the following empirical formula: ; Wherein: an effective diffusion radius for the slurry; Is the length of the grouting section; is the porosity of the rock mass; The value range of the slurry filling coefficient is 0.7-0.9; The grouting pressure is dynamically controlled according to grouting quantity and on-site monitoring, the initial pressure is set to be 0.5-1.0 MPa, and the grouting quantity is taken as a target quantity.
3. The method according to claim 1, characterized in that in step S3, the yielding time of the U-profile steel collapsible bracket is controlled by the following mechanical criteria: when the support resistance F, monitored by the pressure sensor mounted on the support, meets the following relationship with the surrounding rock deformation pressure P, the support begins to collapse: ; Wherein: the yield load of the U-shaped steel bracket; the yielding coefficient is an empirical value between 0.6 and 0.8, and is used for ensuring that the support starts to slide and yielding before reaching the ultimate bearing capacity.
4. The method according to claim 1, wherein in step S4, the timing of performing permanent borehole wall construction is determined by intelligent criteria based on the rate of deformation of the surrounding rock: By monitoring the convergent displacement of the well wall in real time, the construction of the permanent well wall can be carried out after the displacement rate v (T) meets the following conditions and is stable for at least T time: ; Wherein: The displacement rate at the current moment; the current accumulated displacement is used; For a monitoring time interval (d); And the critical displacement rate is determined according to the surrounding rock grade, the value range is 0.5-1.0 mm/d, and T is the stable observation period.
5. The method according to claim 1, wherein in step S5, the grouting pressure of the post-wall grouting is controlled in stages, the final pressure thereof According to hydrostatic pressure And surrounding rock characteristics determination: ; Wherein: Is the hydrostatic pressure at the grouting point; g is gravity acceleration; The vertical height from the grouting point to the underground water line; In order to overcome the additional pressure of the slurry flowing resistance in the cracks, the value range is 0.1-0.3 MPa, k is a safety coefficient, and the value range is 1.2-1.5.
6. The method of claim 1, wherein the three-dimensional waterproof and drainage system is provided with a buried rubber water stop at a construction joint of an open trench and a dark tunnel, and the installation position of the buried rubber water stop is accurately checked by the following algorithm: in the BIM model, the central line of the water stop belt coincides with the theoretical central line of the construction joint, and the spatial position deviation delta of the water stop belt must satisfy the following conditions: ; Wherein: In the three-dimensional coordinate system, the deviation of the central line of the water stop belt relative to the theoretical central line of the construction joint in three directions is shown, and [ delta ] is the allowable maximum deviation.
7. The method of claim 3 or 4, comprising a BIM-based construction dynamic regulation system that performs the following algorithm flow to achieve closed loop control: a. data acquisition, namely acquiring data D (t) from a pressure sensor and a displacement monitoring point in real time; b. Model updating, namely inputting D (t) into the BIM model, and updating the mechanical state M (t) of the model; c. Criterion calculation, namely calculating key criteria based on M (t), including yielding criteria And lining timing criterion ; D. Decision output will be And And comparing the pre-warning instruction with a preset threshold value, and automatically sending a pre-warning or construction instruction to the terminal equipment if the pre-warning instruction meets the condition.
8. The method according to claim 1, wherein the sprayed concrete thickness d of the skin stress containment vessel in step S1 is optimally designed by the following formula: ; Wherein: The potential sliding force of the soil body on the surface layer of the upward slope is calculated by soil mechanics, D is the characteristic length of the sliding surface; Shear strength for shotcrete; The value range is 0.6-0.8 for the reduction coefficient.
9. The method according to claim 1, characterized in that the arrangement pitch a and the extrapolation angle α of the foreleg in step S2 are determined by the following joint algorithm to form an effective load arch: ; ; Wherein: the effective supporting range of the single pipe shed is provided; The length of the pipe shed is the length of the pipe shed; The value of the overlap coefficient is larger than 1.2.
10. The method of claim 1, wherein the U-section steel collapsible bracket and permanent concrete well wall are considered as a composite structure, which ultimately combines load bearing capacity The check is performed by the following formula: ; Wherein: The residual bearing capacity of the U-shaped steel bracket in the composite state is obtained; the bearing capacity of the reinforced concrete well wall; And The values of the cooperative work coefficients of the steel support and the concrete well wall are respectively 0.8-1.0. The design needs to meet Wherein Gamma is the safety factor for the maximum expected surrounding rock pressure.

Description

Active control and collaborative supporting construction method for inclined shaft open channel-dark cave junction section Technical Field The invention relates to the technical field of mine and tunnel engineering construction, in particular to an active control and collaborative support construction method for an inclined shaft open channel-dark cave junction section. Background In inclined shaft engineering construction, the junction of an open trench excavation section and a hidden tunnel excavation section is the key node with the weakest geological condition and the highest construction risk. The section of surrounding rock is usually in a strong wind zone, has joint development and extremely poor self-stabilizing capability, is directly influenced by surface water and rainfall, and the traditional construction method often causes safety accidents such as working face collapse, roof fall, water leakage and the like due to the fact that a support system is not systematic, the pre-support strength is insufficient and the waterproof measure is not thorough, so that the construction safety, the progress and the engineering quality are seriously restricted. Disclosure of Invention The invention aims to overcome the defects of the prior art and provides an active control and cooperative support construction method for an inclined shaft open channel-dark cave junction section. In order to achieve the above purpose, the present invention provides the following technical solutions: the application provides an active control and cooperative support construction method for an inclined shaft open channel-dark cave junction section, which comprises the following sequential steps: S1, performing guniting protection on an upward slope excavated by an open trench to form a surface stress closed shell; S2, constructing an advanced pipe shed at the arch part of the excavated contour line designed in the hidden cave, and grouting to form a deep pressure-bearing arch and a composite stress shell; s3, mechanically excavating under the protection of the composite pre-support system, and immediately erecting a U-shaped steel contractible support as temporary support after excavating; s4, constructing a reinforced concrete permanent well wall on the inner side of the temporary support; s5, grouting backfilling and reinforcing are carried out on the back of the permanent well wall through the pre-buried grouting pipe, and the full-ring closed three-dimensional waterproof and drainage system is formed. Optionally, in step S2, the grouting parameter of the foreline shed is dynamically adjusted according to the rock breaking degree, and the single-hole grouting amount Q is estimated by the following empirical formula: Wherein: an effective diffusion radius for the slurry; Is the length of the grouting section; is the porosity of the rock mass; The value range of the slurry filling coefficient is 0.7-0.9; The grouting pressure is dynamically controlled according to grouting quantity and on-site monitoring, the initial pressure is set to be 0.5-1.0 MPa, and the grouting quantity is taken as a target quantity. Optionally, in step S3, the yielding time of the U-shaped steel retractable bracket is controlled by the following mechanical criteria: when the support resistance F, monitored by the pressure sensor mounted on the support, meets the following relationship with the surrounding rock deformation pressure P, the support begins to collapse: Wherein: the yield load of the U-shaped steel bracket; the yielding coefficient is an empirical value between 0.6 and 0.8, and is used for ensuring that the support starts to slide and yielding before reaching the ultimate bearing capacity. Optionally, in step S4, the timing of performing permanent well wall construction is determined by an intelligent criterion based on the deformation rate of the surrounding rock: By monitoring the convergent displacement of the well wall in real time, the construction of the permanent well wall can be carried out after the displacement rate v (T) meets the following conditions and is stable for at least T time: Wherein: The displacement rate at the current moment; the current accumulated displacement is used; For a monitoring time interval (d); And the critical displacement rate is determined according to the surrounding rock grade, the value range is 0.5-1.0 mm/d, and T is the stable observation period. Optionally, in step S5, the grouting pressure of the post-wall grouting is controlled in stages, the final pressure thereofAccording to hydrostatic pressureAnd surrounding rock characteristics determination: Wherein: Is the hydrostatic pressure at the grouting point; g is gravity acceleration; The vertical height from the grouting point to the underground water line; In order to overcome the additional pressure of the slurry flowing resistance in the cracks, the value range is 0.1-0.3 MPa, k is a safety coefficient, and the value range is 1.2-