Ground treatment method for advancing shield tunneling machine to penetrate through fault zone

Abstract

The invention discloses a ground treatment method for an advanced shield tunneling machine to penetrate through a fault zone. The ground treatment method comprises the steps that firstly, drilling is conducted according to a roadway design line and the width of the fault zone; the distance between the center lines of two adjacent roadways is dm, and the width of the fault zone in the tunneling direction of the shield tunneling machine is Dm; on the plane, the treatment length in the tunneling direction of the shield tunneling machine is D + 100, and on the section, a + b rows of drill holes are designed, a rows are arranged above a roadway top plate, and b rows are arranged below a roadway bottom plate; 2, grouting parameters are designed according to fault hydrogeological conditions; each drilling treatment section is divided into three grouting sections, first section grouting is carried out when drilling is carried out to a fault layer, second section grouting is carried out when drilling is carried out to a fault zone, and third section grouting is carried out when drilling is carried out 50 m away from the fault zone. The position of a fault is accurately explored and judged in advance through a roadway hole, cracks are blocked through ground high-pressure grouting, surrounding rock is reinforced, the strength of the surrounding rock is improved, the performance of the surrounding rock is improved, advanced treatment is achieved, and efficient tunneling and safe production of a mine are guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine fault management, and relates to a ground management method for an advance shield machine passing through a fault zone. Background Art

[0002] As shallow coal resources gradually become depleted, deep resource mining has become the new normal in resource development. The deep geological conditions of "three highs and one disturbance" pose an increasingly significant threat to the stability of tunnel surrounding rock and mine water inrush. During mine construction, system tunnels inevitably pass through faults and fracture zones. Especially when the fault zone is too deep and large, the surrounding rock is easily deformed, permeable, has low strength, and poor water resistance. When tunneling through faults, there may be engineering geological problems such as tunnel roof collapse, collapse, and deformation. Faults are easily activated by the disturbance of tunnel excavation and become water channels, connecting to the underlying high-pressure, water-rich aquifers and inducing water inrush disasters. At present, in order to improve construction efficiency, shield machines are often used for tunnel excavation, which have higher requirements for surrounding rock stability. Therefore, ensuring the surrounding rock remains stable when the shield machine passes through the fault zone and preventing mine water inrush is the basis for safe and efficient mine production.

[0003] Traditional advance grouting to reinforce fault fracture zones is mainly carried out underground, that is, grouting is carried out into the fault fracture zone in front of the tunnel through underground grouting holes. However, due to the limitations of drilling exploration range and equipment capacity, advance treatment cannot be achieved. The cross-operation cycle of treatment and excavation is long, the grouting pressure is low, the grouting volume is small, the slurry diffusion is limited, the shielding effect cannot be guaranteed, and there is a risk of inducing water inrush in the water channel, affecting the safe production of the mine. For faults with extremely complex conditions, pipe-roof advance support is adopted, but this method is expensive, the process is complex and frequent, the construction period is long, and it may cause the working face to become unstable. There are major safety hazards and high risks. Advance treatment cannot be achieved, affecting the efficient excavation and safe production of the mine.

[0004] In order to effectively solve the problems of surrounding rock stability and fault water inrush faced by shield machines when excavating through fault zones, it is urgent to propose a ground drilling and injection method for efficient fault zone management to provide scientific guidance for the shield machine to smoothly pass through the fault zone. Summary of the Invention

[0005] The purpose of the present invention is to provide a ground drilling and injection method for an advance shield machine to pass through a fault zone, thereby solving the problems of poor fault reinforcement effect and fault water inrush in the prior art.

[0006] The technical solution adopted in the present invention is:

[0007] A ground treatment method for an advance shield tunneling machine passing through a fault zone, comprising:

[0008] Step 1: Drill holes according to the tunnel design line and the width of the fault zone; the distance between the center lines of two adjacent tunnels is dm, and the width of the fault zone along the shield machine excavation direction is Dm;

[0009] On the plane, the treatment length along the shield machine excavation direction is D+100, and a row of drill holes is set along the design center line of the track tunnel, the design center line of the transport tunnel, the design center line of the return air tunnel, the design center line of the track tunnel 2r outward, and the design center line of the return air tunnel 2r outward; where r is the slurry diffusion radius m, and the slurry diffusion radius is given by Formula 1: Determine, where k is the permeability of the injected rock layer m 2 , h is the grouting pressure head m; t is the grouting time h; n is the porosity of the rock layer being injected; β is the ratio of the slurry viscosity to the water viscosity; r0 is the grouting borehole radius m;

[0010] On the cross section, design a+b rows of drill holes, a row of top plate holes above the center line of the roadway, b row of bottom plate holes below the center line; according to the thickness of the bottom plate safety waterproof layer sm, Where: γ is the average density of the bottom aquiclude MN / m 2 ; L is the width of the tunnel floor m; Kp is the average tensile strength of the floor aquiclude MPa; P is the water head pressure MPa borne by the floor aquiclude; determine the total number of bottom plate holes in b rows, s is the thickness of the safety waterproof layer m, b is rounded up, and the first row of drill holes below the bottom plate is located at r below the bottom plate;

[0011] According to the roof failure height s', Where: s' is the roof failure height in the excavation process m; p' is the original rock stress in MPa; p i is the support resistance MPa; r d is the roadway radius m; β is the internal friction angle °, c is the cohesion of the surrounding rock MPa; determine that there are a rows of top plate holes, a is rounded up; the first row of drill holes above the top plate is located at position r on the top plate;

[0012] Step 2: Design grouting parameters according to the fault hydrogeological conditions;

[0013] Each drilling treatment section is divided into three grouting sections. The first section of grouting is carried out when drilling to the fault surface, the second section of grouting is carried out when drilling out of the fault zone, and the third section of grouting is carried out 50m beyond the fault zone.

[0014] Optionally, pure cement is used as the grouting material for the three-stage grouting, and the grouting termination pressure is not less than 1.5 times the hydrostatic pressure of the grouting layer.

[0015] Optional, wherein, the slurry specific gravity of grouting section one is 1.2-1.4, and the grouting flow rate is 90L / min-250L / min (this section is the first grouting section for the fault zone, so low specific gravity and high flow rate are selected. The slurry is diffused as much as possible); the slurry specific gravity of grouting section two is 1.4-1.5, and the grouting flow rate is 52L / min-160L / min (the grouting in this section is mainly for the fault zone, which has good water conductivity and a long slurry diffusion distance, which can easily cause ineffective diffusion of the slurry. Therefore, grouting parameters with high specific gravity and low flow rate are selected to prevent waste of grouting materials while ensuring the treatment effect); the slurry specific gravity of grouting section three is 1.4-1.5, and the grouting flow rate is 90L / min-250L / min (the grouting in this section selects high specific gravity and high flow rate. On the one hand, it strengthens the treatment of the first two sections, and also serves to test the grouting effect of the first two sections).

[0016] Optionally, the coal mine tunnel is divided into a track tunnel, a transport tunnel and a return air tunnel, the track tunnel and the return air tunnel are on both sides, and the transport tunnel is in the middle;

[0017] The distance between the center lines of two adjacent tunnels is d; the tunnels are divided into flat tunnels and inclined tunnels according to the inclination angle, and the drilling trajectory of the treatment section is designed to be parallel to the tunnel.

[0018] Optionally, the drilling hole is not designed along the center line of the tunnel to avoid accidents in the hole that may cause the drilling tool to be unable to be salvaged, thereby affecting the normal excavation of the tunnel.

[0019] Optionally, design two hole groups D1 and D2;

[0020] The D1 hole group is the tunnel roof hole, with a total of 5a branch holes (D1-1~D1-a); the D2 hole group is the tunnel floor hole, with a total of 5b branch holes (D2-1~D2-b).

[0021] Optionally, the method further includes step 3: determining the construction sequence of each drilling hole; the construction sequence of the D1 hole group is: drilling holes in a row extending outside the design center line of the track lane, drilling holes in a row of track lanes, drilling holes in a row of transport lanes, drilling holes in a row of return air lanes, and drilling holes in a row extending outside the design center line of the return air lanes;

[0022] The construction sequence of D2 hole group is: drilling holes in the transport tunnel, drilling holes in the return air tunnel, drilling holes outside the design center line of the return air tunnel, drilling holes outside the design center line of the track tunnel, and drilling holes in the track tunnel.

[0023] Optional, specifically: D1-1 is a hole drilled above the top plate of the design centerline of the rail roadway, D1-2 is a hole drilled above the top plate of the design centerline of the rail roadway, D1-3 is a hole drilled above the top plate of the design centerline of the transport roadway, D1-4 is a hole drilled above the top plate of the design centerline of the return air roadway, D1-5 is a hole drilled above the top plate of the design centerline of the return air roadway, D1-6 is a hole drilled 3 meters above the top plate of the design centerline of the rail roadway, D1-7 is a hole drilled 3 meters above the top plate of the design centerline of the rail roadway, D1-8 is a hole drilled 3 meters above the top plate of the design centerline of the transport roadway, D1-9 is a hole drilled 3 meters above the top plate of the design centerline of the return air roadway, D1-10 is a hole drilled 3 meters above the top plate of the design centerline of the return air roadway, and the same applies to the remaining holes;

[0024] D2-1 is a hole drilled below the bottom plate of the design centerline of the track laneway, D2-2 is a hole drilled below the bottom plate of the design centerline of the track laneway, D2-3 is a hole drilled below the bottom plate of the design centerline of the transport laneway, D2-4 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-5 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-6 is a hole drilled 3 meters below the bottom plate of the design centerline of the track laneway, D2-7 is a hole drilled 3 meters below the bottom plate of the design centerline of the track laneway, D2-8 is a hole drilled 3 meters below the bottom plate of the design centerline of the transport laneway, D2-9 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, D2-10 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, and the same applies to the remaining holes.

[0025] Two groups of holes are constructed simultaneously. On the cross section of each hole group, construction of one row is followed by another row. There are a total of five rows in each hole group. To avoid slurry leakage during top and bottom plate drilling, there is always at least one row between the D1 hole group and the D2 hole group.

[0026] The beneficial effects of the present invention are:

[0027] 1. Through accurate exploration along the tunnel borehole, the fault location is determined, and the cracks are sealed by high-pressure grouting on the ground. The surrounding rock is reinforced, the surrounding rock strength is increased, and the surrounding rock performance is improved. This achieves advanced treatment and ensures efficient mine excavation and safe production.

[0028] 2. The present invention adopts a three-stage graded grouting method, adopts different grouting parameters for different parts of the fault zone, and significantly improves the grouting efficiency and the reinforcement effect of the fault surrounding rock. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The accompanying drawings are used to provide a further understanding of the present disclosure and constitute a part of the specification. Together with the following detailed description, they are used to explain the present disclosure but do not constitute a limitation of the present disclosure. In the accompanying drawings:

[0030] Figure 1This is a cross-sectional view of the track lane in Example 1;

[0031] Figure 2 This is a cross-sectional view of the main transport tunnel in Example 1;

[0032] Figure 3 This is a cross-sectional view of the return air lane in Example 1;

[0033] Figure 4 This is a plan view of the drilling design in Example 1;

[0034] Figure 5 This is the drilling arrangement diagram in Example 1;

[0035] Figure 6 This is a construction effect diagram in Example 1. DETAILED DESCRIPTION

[0036] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0037] The ground treatment method for an advance shield machine passing through a fault zone of the present invention comprises:

[0038] Step 1: Drill holes according to the tunnel design line and the width of the fault zone; the distance between the center lines of two adjacent tunnels is dm, and the width of the fault zone along the shield machine excavation direction is Dm;

[0039] On the plane, the treatment length along the shield machine excavation direction is D+100, and a row of drill holes is set along the design center line of the track tunnel, the design center line of the transport tunnel, the design center line of the return air tunnel, the design center line of the track tunnel 2r outward, and the design center line of the return air tunnel 2r outward; where r is the slurry diffusion radius m, and the slurry diffusion radius is given by Formula 1: Determine, where k is the permeability of the injected rock layer m 2 , h is the grouting pressure head m; t is the grouting time h; n is the porosity of the rock layer being injected; β is the ratio of the slurry viscosity to the water viscosity; r0 is the grouting borehole radius m;

[0040] On the cross section, design a+b rows of drill holes, a row of top plate holes above the center line of the roadway, b row of bottom plate holes below the center line; according to the thickness of the bottom plate safety waterproof layer sm, Where: γ is the average density of the bottom aquiclude MN / m 2 ; L is the width of the tunnel floor m; Kp is the average tensile strength of the floor aquiclude MPa; P is the water head pressure MPa borne by the floor aquiclude; determine the total number of bottom plate holes in b rows, s is the thickness of the safety waterproof layer m, b is rounded up, and the first row of drill holes below the bottom plate is located at r below the bottom plate;

[0041] According to the roof failure height s', Where: s' is the roof failure height in the excavation process m; p' is the original rock stress in MPa; p i is the support resistance MPa; r d is the roadway radius m; β is the internal friction angle °, c is the cohesion of the surrounding rock MPa; determine that there are a rows of top plate holes, a is rounded up; the first row of drill holes above the top plate is located at position r on the top plate;

[0042] Step 2: Design grouting parameters according to the fault hydrogeological conditions;

[0043] Each drilling treatment section is divided into three grouting sections. The first section of grouting is carried out when drilling to the fault surface, the second section of grouting is carried out when drilling out of the fault zone, and the third section of grouting is carried out 50m beyond the fault zone.

[0044] In the present invention, pure cement is selected as the grouting material for the three-stage grouting, and the grouting termination pressure is not less than 1.5 times the hydrostatic pressure of the grouting layer.

[0045] In the present invention, the slurry specific gravity of the grouting section one is 1.2 to 1.4, and the grouting flow rate is 90 L / min to 250 L / min (this section is the first grouting section for the fault zone, so low specific gravity and high flow rate are selected. The slurry is diffused as much as possible); the slurry specific gravity of the grouting section two is 1.4 to 1.5, and the grouting flow rate is 52 L / min to 160 L / min (the grouting in this section is mainly for the fault zone, which has good water conductivity and a long slurry diffusion distance, which easily causes ineffective diffusion of the slurry. Therefore, grouting parameters with high specific gravity and low flow rate are selected to prevent waste of grouting materials while ensuring the treatment effect); the slurry specific gravity of the grouting section three is 1.4 to 1.5, and the grouting flow rate is 90 L / min to 250 L / min (the grouting in this section selects high specific gravity and high flow rate. On the one hand, it strengthens the treatment of the first two sections, and also serves to test the grouting effects of the first two sections).

[0046] In the present invention, the coal mine tunnels are divided into rail tunnels, transport tunnels and return air tunnels, with the rail tunnels and return air tunnels on both sides and the transport tunnels in the middle; the distance between the center lines of two adjacent tunnels is d; the tunnels are divided into flat tunnels and inclined tunnels according to the inclination angle, and the drilling trajectory of the treatment section is designed to be parallel to the tunnel.

[0047] In the present invention, the drilling hole is not designed along the center line of the tunnel (ie, the drilling trajectory does not coincide with the tunnel), so as to avoid accidents in the hole that cause the drilling tool to be unable to be salvaged, thereby affecting the normal tunnel excavation.

[0048] In the present invention, two hole groups D1 and D2 are designed;

[0049] The D1 hole group is the tunnel roof hole, with a total of 5a branch holes (D1-1 to D1-a); the D2 hole group is the tunnel floor hole, with a total of 5b branch holes (D2-1 to D2-b). The number of a and b here is determined by the formula,

[0050] The present invention also includes step three: determining the construction sequence of each drilling hole; the construction sequence of the D1 hole group is: drilling holes in a row expanding outward from the design center line of the rail tunnel, drilling holes in a row of rail tunnels, drilling holes in a row of transport tunnels, drilling holes in a row of return air tunnels, and drilling holes in a row expanding outward from the design center line of the return air tunnel; the construction sequence of the D2 hole group is: drilling holes in a row of transport tunnels, drilling holes in a row of return air tunnels, drilling holes in a row expanding outward from the design center line of the return air tunnel, drilling holes in a row expanding outward from the design center line of the rail tunnel, and drilling holes in a row of rail tunnels.

[0051] In a specific embodiment of the present invention, for example: D1-1 is a hole drilled above the top plate of the design center line of the track lane, D1-2 is a hole drilled above the top plate of the design center line of the track lane, D1-3 is a hole drilled above the top plate of the design center line of the transport lane, D1-4 is a hole drilled above the top plate of the design center line of the return air lane, D1-5 is a hole drilled above the top plate of the design center line of the return air lane, D1-6 is a hole drilled 3r above the top plate of the design center line of the track lane, D1-7 is a hole drilled 3r above the top plate of the design center line of the track lane, D1-8 is a hole drilled 3r above the top plate of the design center line of the transport lane, D1-9 is a hole drilled 3r above the top plate of the design center line of the return air lane, D1-10 is a hole drilled 3r above the top plate of the design center line of the return air lane, and the same applies to the remaining holes.

[0052] D2-1 is a hole drilled below the bottom plate of the design centerline of the track laneway, D2-2 is a hole drilled below the bottom plate of the design centerline of the track laneway, D2-3 is a hole drilled below the bottom plate of the design centerline of the transport laneway, D2-4 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-5 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-6 is a hole drilled 3 meters below the bottom plate of the design centerline of the track laneway, D2-7 is a hole drilled 3 meters below the bottom plate of the design centerline of the track laneway, D2-8 is a hole drilled 3 meters below the bottom plate of the design centerline of the transport laneway, D2-9 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, D2-10 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, and the same applies to the remaining holes.

[0053] Two groups of holes are constructed simultaneously. On the cross section of each hole group, construction of one row is followed by another row. There are a total of five rows in each hole group. To avoid slurry leakage during top and bottom plate drilling, there is always at least one row between the D1 hole group and the D2 hole group.

[0054] Example 1:

[0055] Combine Figure 1-5 The ground grouting method for an advance shield machine passing through a reverse fault zone of the present invention comprises:

[0056] Step 1: Based on the tunnel design line and fault zone width;

[0057] Generally, coal mine system tunnels are divided into rail tunnels ( Figure 1 ), transport tunnel ( Figure 2 ) and return airway ( Figure 3 ), with the rail roadway and return air roadway on either side, and the transport roadway in the middle. The distance between the centerlines of two adjacent roadways is d. The roadway cross-sectional area is generally approximately 5m x 5m. Roadways are generally divided into horizontal and inclined roadways based on their inclination. The drilling trajectory for the treatment section is generally designed parallel to the roadway. The width of the fault zone along the shield machine's excavation direction is Dm.

[0058] On a plane ( Figure 4 ) The treatment range along the shield machine's excavation direction is: 50m outward from one fault zone to 50m outward from the other fault zone, with a treatment length of D+100. Five rows of drill holes are designed along the roadway direction, namely the track roadway design centerline, the transport roadway design centerline, the return air roadway design centerline, the track roadway design centerline extended 2r outward, and the return air roadway design centerline extended 2r outward. Where r is the slurry diffusion radius. The slurry diffusion radius is given by Formula 1: Determine, where r is the slurry diffusion radius (m), k is the permeability of the injected rock formation (m 2 ), h is the grouting pressure head (m); t is the grouting time (h); n is the porosity of the injected rock formation; β is the ratio of the slurry viscosity to the water viscosity; r0 is the grouting borehole radius (m).

[0059] On the cross section, a+b rows of boreholes are designed, with a row above the tunnel roof and b row below the floor. According to the thickness s of the floor safety waterproof layer, Where: s is the thickness of the safety waterproof layer (m); γ is the average density of the bottom waterproof layer (MN / m 2 ); L is the width of the tunnel floor (m); Kp is the average tensile strength of the floor aquiclude (MPa); P is the water head pressure (MPa) borne by the floor aquiclude. Determine the number of rows of floor holes drilled. s is the thickness of the safety waterproof layer (m), r is the slurry diffusion radius (m), and b is rounded up. The first row of drill holes below the bottom plate is located at r below the bottom plate.

[0060] According to the roof failure height s', Where: s' is the height of roof failure during excavation (m); p' is the original rock stress (MPa); p i is the support resistance (MPa); r d is the roadway radius (m); β is the internal friction angle (°), and c is the cohesion of the surrounding rock (MPa). Determine the number of rows of top plate holes, s' is the roof failure height (m), r is the slurry diffusion radius (m), and b is rounded up. The first row of drill holes above the roof is located at position r on the roof.

[0061] In particular, the drilling holes are not designed along the center line of the tunnel to avoid accidents in the hole that may cause the drilling tools to be unable to be salvaged, thus affecting the normal excavation of the tunnel.

[0062] Design two hole groups D1, D2 ( Figure 5 The D1 hole group is the tunnel roof hole, with a total of 5a branch holes (D1-1 to D1-A); the D2 hole group is the tunnel floor hole, with a total of 5b branch holes (D2-1 to D2-B);

[0063] Step 2: Design grouting parameters according to the fault hydrogeological conditions;

[0064] Each drilling treatment section is divided into three grouting sections. The first section of grouting is carried out when drilling to the fault surface, the second section of grouting is carried out when drilling out of the fault zone, and the third section of grouting is carried out 50m beyond the fault zone.

[0065] The grouting material for the three-stage grouting is pure cement, and the grouting termination pressure is not less than 1.5 times the hydrostatic pressure of the grouting layer.

[0066] Among them, the slurry specific gravity of grouting section one is 1.2-1.4, and the grouting flow rate is 90L / min-250L / min (this section is for the first grouting of the fault zone, so low specific gravity and high flow rate are selected to make the slurry diffuse as much as possible); the slurry specific gravity of grouting section two is 1.4-1.5, and the grouting flow rate is 52L / min-160L / min (the grouting in this section is mainly for the fault zone. The fault zone has good water conductivity and the slurry diffusion distance is long, which easily causes ineffective diffusion of the slurry. Therefore, the grouting parameters of high specific gravity and low flow rate are selected to prevent the waste of grouting materials while ensuring the treatment effect); the slurry specific gravity of grouting section three is 1.4-1.5, and the grouting flow rate is 90L / min-250L / min (the grouting in this section is selected with high specific gravity and high flow rate. On the one hand, it strengthens the treatment of the first two sections, and also serves to test the grouting effect of the first two sections);

[0067] Step 3: Determine the construction sequence of each drilling hole;

[0068] D1-1 is a hole drilled above the top plate of the design centerline of the rail laneway, D1-2 is a hole drilled above the top plate of the design centerline of the rail laneway, D1-3 is a hole drilled above the top plate of the design centerline of the transport laneway, D1-4 is a hole drilled above the top plate of the design centerline of the return air laneway, D1-5 is a hole drilled above the top plate of the design centerline of the return air laneway, D1-6 is a hole drilled 3 meters above the top plate of the design centerline of the rail laneway, D1-7 is a hole drilled 3 meters above the top plate of the design centerline of the rail laneway, D1-8 is a hole drilled 3 meters above the top plate of the design centerline of the transport laneway, D1-9 is a hole drilled 3 meters above the top plate of the design centerline of the return air laneway, D1-10 is a hole drilled 3 meters above the top plate of the design centerline of the return air laneway, and the same applies to the remaining holes.

[0069] D2-1 is a hole drilled below the bottom plate of the design centerline of the rail laneway, D2-2 is a hole drilled below the bottom plate of the design centerline of the rail laneway, D2-3 is a hole drilled below the bottom plate of the design centerline of the transport laneway, D2-4 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-5 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-6 is a hole drilled 3 meters below the bottom plate of the design centerline of the rail laneway, D2-7 is a hole drilled 3 meters below the bottom plate of the design centerline of the rail laneway, D2-8 is a hole drilled 3 meters below the bottom plate of the design centerline of the transport laneway, D2-9 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, D2-10 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, and the rest of the holes are drilled similarly.

[0070] Two groups of holes are constructed simultaneously. Each group of holes is constructed one row at a time, with the next row constructed after the previous row. Each group of holes has a total of five rows. To prevent slurry from slurry from drilling through the roof and floor plates, there is always at least one row between the D1 and D2 groups. Generally, the D1 group of holes is constructed in the following order: drilling rows extending from the design centerline of the rail roadway, drilling rows of rail roadway, drilling rows of transport roadway, drilling rows of return air roadway, and finally drilling rows extending from the design centerline of the return air roadway.

[0071] The construction sequence of D2 hole group is: drilling holes in the transport tunnel, drilling holes in the return air tunnel, drilling holes outside the design center line of the return air tunnel, drilling holes outside the design center line of the track tunnel, and drilling holes in the track tunnel.

[0072] Combine Figure 6 When the width of the fault fracture zone is 20m, it usually takes more than 6 months to treat the fault by short-hole grouting of underground pipe roofs, and the treatment effect is not good. After applying the method of the present invention, the treatment period is significantly shortened. It only takes 3 months for the shield machine to pass through the fault smoothly. After excavation, obvious cement is found on both sides of the tunnel.

[0073] The preferred embodiments of the present disclosure are described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. Within the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the scope of protection of the present disclosure.

[0074] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any appropriate manner without contradiction. In order to avoid unnecessary repetition, the present disclosure will not further describe various possible combinations.

[0075] In addition, the various embodiments of the present disclosure may be arbitrarily combined, and as long as they do not violate the concept of the present disclosure, they should also be regarded as the contents disclosed by the present disclosure.

Claims

1. A ground treatment method for an advance shield machine passing through a fault zone, characterized in that: include: Step 1: Drill holes according to the tunnel design line and the width of the fault zone; the distance between the center lines of two adjacent tunnels is dm, and the width of the fault zone along the shield machine excavation direction is Dm; On the plane, the treatment length along the shield machine excavation direction is D+100, and a row of drill holes is set along the design center line of the track tunnel, the design center line of the transport tunnel, the design center line of the return air tunnel, the design center line of the track tunnel 2r outward, and the design center line of the return air tunnel 2r outward; where r is the slurry diffusion radius m, and the slurry diffusion radius is given by Formula 1: Determine, where k is the permeability of the injected rock layer m 2 , h is the grouting pressure head m; t is the grouting time h; n is the porosity of the rock layer being injected; β is the ratio of the slurry viscosity to the water viscosity; r0 is the grouting borehole radius m; On the cross section, design a+b rows of drill holes, a row of top plate holes above the center line of the roadway, b row of bottom plate holes below the center line; according to the thickness of the bottom plate safety waterproof layer sm, Where: γ is the average density of the bottom aquiclude MN / m 2 ; L is the width of the tunnel floor in m; Kp is the average tensile strength of the floor aquiclude in MPa; P is the water head pressure borne by the floor aquiclude in MPa; Make sure there are b rows of holes drilled in the bottom plate. s is the thickness of the safety waterproof layer m, b is rounded up, and the first row of drill holes below the bottom plate is located at r below the bottom plate; According to the roof failure height s', Where: s' is the roof damage height m during the excavation process; p' is the original rock stress in MPa; p i is the support resistance MPa; r d is the roadway radius m; β is the internal friction angle °, c is the cohesion of the surrounding rock MPa; determine that there are a rows of top plate holes, a is rounded up; the first row of drill holes above the top plate is located at position r on the top plate; Step 2: Design grouting parameters according to the fault hydrogeological conditions; Each drilling treatment section is divided into three grouting sections. The first section of grouting is carried out when drilling to the fault surface, the second section of grouting is carried out when drilling out of the fault zone, and the third section of grouting is carried out 50m beyond the fault zone.

2. The ground treatment method for an advance shield machine passing through a fault zone according to claim 1 is characterized in that: The grouting material for the three-stage grouting is pure cement, and the grouting termination pressure is not less than 1.5 times the hydrostatic pressure of the grouting layer.

3. The ground treatment method for an advance shield machine passing through a fault zone according to claim 1 or 2, characterized in that: in, The slurry specific gravity of grouting section one is 1.2~1.4, and the grouting flow rate is 90L / min~250L / min (this section is the first grouting section for the fault zone, so low specific gravity and high flow rate are selected to make the slurry diffuse as much as possible); the slurry specific gravity of grouting section two is 1.4~1.5, and the grouting flow rate is 52L / min~160L / min (the grouting in this section is mainly for the fault zone, which has good water conductivity and a long slurry diffusion distance, which can easily cause ineffective diffusion of the slurry. Therefore, grouting parameters with high specific gravity and low flow rate are selected to prevent waste of grouting materials while ensuring the treatment effect); the slurry specific gravity of grouting section three is 1.4~1.5, and the grouting flow rate is 90L / min~250L / min (the grouting in this section selects high specific gravity and high flow rate. On the one hand, it strengthens the treatment of the first two sections, and also serves to test the grouting effect of the first two sections).

4. The ground treatment method for an advance shield machine passing through a fault zone according to claim 1 or 2, characterized in that: The coal mine tunnels are divided into rail tunnels, transport tunnels and return air tunnels, with the rail tunnels and return air tunnels on both sides and the transport tunnel in the middle; The distance between the center lines of two adjacent tunnels is d; the tunnels are divided into flat tunnels and inclined tunnels according to the inclination angle, and the drilling trajectory of the treatment section is designed to be parallel to the tunnel.

5. The ground treatment method for an advance shield machine passing through a fault zone according to claim 1 or 2, characterized in that: The drilling holes are not designed along the center line of the tunnel to avoid accidents in the hole that may cause the drilling tools to be unable to be salvaged, thus affecting the normal excavation of the tunnel.

6. The ground treatment method for an advance shield machine passing through a fault zone according to claim 1 or 2, characterized in that: Design two hole groups D1 and D2; The D1 hole group is the tunnel roof hole, with a total of 5a branch holes (D1-1~D1-a); the D2 hole group is the tunnel floor hole, with a total of 5b branch holes (D2-1~D2-b).

7. The ground treatment method for an advance shield machine passing through a fault zone according to claim 6, characterized in that: The process also includes step 3: determining the construction sequence of each drilling hole; the construction sequence of the D1 hole group is: drilling holes in a row extending outside the design center line of the rail roadway, drilling holes in a row of rail roadway holes, drilling holes in a row of transport roadway holes, drilling holes in a row of return air roadway holes, and drilling holes in a row extending outside the design center line of the return air roadway; The construction sequence of D2 hole group is: drilling holes in the transport tunnel, drilling holes in the return air tunnel, drilling holes outside the design center line of the return air tunnel, drilling holes outside the design center line of the track tunnel, and drilling holes in the track tunnel.

8. The ground treatment method for a forward shield machine passing through a fault zone according to claim 6, characterized in that: Specifically: D1-1 is a hole drilled above the top plate of the design centerline of the rail roadway, D1-2 is a hole drilled above the top plate of the design centerline of the rail roadway, D1-3 is a hole drilled above the top plate of the design centerline of the transport roadway, D1-4 is a hole drilled above the top plate of the design centerline of the return air roadway, D1-5 is a hole drilled above the top plate of the design centerline of the return air roadway, D1-6 is a hole drilled 3 meters above the top plate of the design centerline of the rail roadway, D1-7 is a hole drilled 3 meters above the top plate of the design centerline of the rail roadway, D1-8 is a hole drilled 3 meters above the top plate of the design centerline of the transport roadway, D1-9 is a hole drilled 3 meters above the top plate of the design centerline of the return air roadway, D1-10 is a hole drilled 3 meters above the top plate of the design centerline of the return air roadway, and the same applies to the remaining holes. D2-1 is a hole drilled below the bottom plate of the design centerline of the track laneway, D2-2 is a hole drilled below the bottom plate of the design centerline of the track laneway, D2-3 is a hole drilled below the bottom plate of the design centerline of the transport laneway, D2-4 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-5 is a hole drilled below the bottom plate of the design centerline of the return air laneway, D2-6 is a hole drilled 3 meters below the bottom plate of the design centerline of the track laneway, D2-7 is a hole drilled 3 meters below the bottom plate of the design centerline of the track laneway, D2-8 is a hole drilled 3 meters below the bottom plate of the design centerline of the transport laneway, D2-9 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, D2-10 is a hole drilled 3 meters below the bottom plate of the design centerline of the return air laneway, and the same applies to the remaining holes. Two groups of holes are constructed simultaneously. On the cross section of each hole group, construction of one row is followed by another row. There are a total of five rows in each hole group. To avoid slurry leakage during top and bottom plate drilling, there is always at least one row between the D1 hole group and the D2 hole group.

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