WO2019056794A1

WO2019056794A1 - Method for constructing cavity behind tunnel lining, and composite lining structure formed after construction

Info

Publication number: WO2019056794A1
Application number: PCT/CN2018/089218
Authority: WO
Inventors: 李占先; 王焕; 周建芳; 顾博渊; 党双宝; 丛义营; 梁万波; 李庭荟; 周华阳; 杨伟辉
Original assignee: 中铁十四局集团有限公司
Priority date: 2017-09-20
Filing date: 2018-05-31
Publication date: 2019-03-28
Also published as: CN107387095A; CN107387095B

Abstract

A method for constructing a cavity behind a tunnel lining comprises the following steps: drilling a pouring hole in a surface of a lining; mounting a pouring pipe inside the pouring hole; pouring foam concrete into a cavity behind the lining via the pouring pipe to form a cushioning layer; filling a cavity of a large collapsed section or other sections of a road; and using waterproof mortar to seal the pouring pipe, such that the surface of the pouring pipe is flush with the lining. The application further provides a composite lining structure formed after completing the above construction steps. A pouring hole is provided inside the lining, the pouring pipe is provided inside the pouring hole, and the pouring pipe is inserted into the cavity at a depth of 1-4 m. The pouring pipe and the pouring hole engage with each other and are respectively sealed. An outer side of the lining is a foam concrete layer, and a waterproof mortar column is provided inside the pouring pipe. The solution effectively reduces the impact of a stone falling from the top of a cavity on the lining, thereby ensuring the integrity of the lining structure.

Description

Construction method of cavity behind tunnel lining and composite lining structure after construction

Technical field

The invention relates to a construction method of a cavity behind a tunnel lining and a composite lining structure after construction, and belongs to the technical field of tunnel construction.

Background technique

Due to the corrosive nature of the groundwater, the tunnel lining concrete is degraded, especially in the leakage water development area. The corrosion is deep and loosely crystallized. When the corrosive medium in the tunnel environment is mainly calcium sulfate, it has a crystalline erosion effect on the concrete, groundwater and The contact of the lining leads to the looseness of the concrete, the strength is gradually reduced, the leakage water development section, and the surface of the sulfate lining in the water is gradually deposited, resulting in the deterioration of the deterioration. There are three main reasons for the formation of voids behind the lining:

(1) The construction year of the tunnel is earlier, the construction method is backward, the blasting control during the construction period is not strict, and the timely and effective backfilling is not carried out after the over-excavation;

(2) The surrounding rock conditions of the tunnel are poor, mainly composed of argillaceous siltstone and silty mudstone. The shape of the surrounding rock is affected by wrinkles, and the surrounding rock is easy to soften and fall off to form a cavity.

(3) After the landslide and water (mud) occurred during the construction period, a large amount of wood was taken for support measures.

In the tunnel, there is a landslide or a swelled cement. The tunnel arch usually collapses. In the prior art, most of the backfills or mortars are backfilled, and then sandblasting is used for filling. However, when using backfilling or mortar backfilling, due to concrete Compared with the weight of the mortar itself, it will increase the lining load, which may cause the lining of the lining to rupture. The sand is filled with sand, and the cavity is enlarged due to the erosion of water. The tunnel cavity is still the risk of the tunnel operation period.

Summary of the invention

The object of the present invention is to provide a construction method for the cavity behind the tunnel lining and a composite lining structure after the construction. The invention effectively reduces the impact of the fallen rock at the top of the cavity on the lining and ensures the safety of the lining structure. The technical solution of the present invention is as follows:

The construction method of the hollow behind the tunnel lining, the steps are as follows:

(1) drilling the slurry hole on the lining surface, the inner diameter of the grouting hole is 30-50cm, the longitudinal spacing of the grouting hole is 2-5m, and the circumferential spacing is 2-5m;

(2) Install a grouting pipe in the grouting hole. The outer diameter of the grouting pipe is 30-50cm, the thickness of the grouting pipe is 2-5mm, and the length of the grouting pipe entering the back of the lining is 1-4m, sealing grouting a gap between the hole and the grouting pipe;

(3) injecting foam concrete into the cavity behind the lining through the grouting pipe to form a buffer layer to reduce the additional load on the tunnel lining;

The raw material composition of the foamed concrete is 200-300 parts of cement, 1.5-3 parts of crack-resistant fiber, 2-3 parts of coagulant, 10-20 parts of foaming agent, and foam stabilizer 5-10. Parts, dispersible latex powder 0.5-1 parts, water 100-140 parts.

The process for preparing the above foam concrete is as follows:

1 mixing cement, anti-cracking fiber, dispersible polymer powder and water to prepare an intermediate slurry;

2 After adding a coagulant, a foaming agent and a foam stabilizer to the intermediate slurry, the foamed concrete is obtained.

Preferably, the raw material composition of the foamed concrete is 245 parts by weight, 2.1 parts of crack resistant fiber, 2.4 parts of coagulant, 16.5 parts of foaming agent, 6 parts of foam stabilizer, 0.7 parts of dispersible polymer powder. 125 parts of water;

The cement is a Portland cement, the coagulant is calcium chloride, the foaming agent is an anionic surfactant and the protein foaming agent is mixed at a mass ratio of 1:1, and the composite foaming agent is stabilized. The foaming agent is sodium carboxymethylcellulose, and the redispersible latex powder is a vinyl acetate and ethylene copolymer resin.

The perfusion pressure is 0.2-1.0 MPa; preferably, the perfusion pressure is 0.6 MPa;

During perfusion construction: firstly inject the left and right arch portions of the longitudinal 20m section, and the slurry flows out to the adjacent perfusion pipe. After the foamed concrete does not flow, the arched infusion is performed;

(4) For the large collapse section, the height of the dome filled foam concrete when the cavity is filled is not less than 2m, in order to effectively reduce the impact of the falling rock on the lining of the cavity and ensure the safety of the lining structure; in other paragraphs, the dome is filled with foam concrete when the cavity is filled. The height is not more than 1m;

(5) The grouting pipe is sealed and compacted with waterproof mortar, and the surface is flush with the lining.

Further, in the step (1), when the hole is easily collapsed during the drilling of the hole, the process of drilling with the pipe is adopted; in the step (3), when the groundwater is enriched and there is a water pressure, the drainage hole is first set. , then infusion.

Further, the inner diameter of the grouting hole is 40 cm, the longitudinal spacing of the grouting hole is 3 m, and the circumferential spacing is 3.5 m; the length of the grouting pipe into the cavity is 3.5 m, and the outer diameter of the grouting pipe is 40 cm, The thickness of the slurry tube is 3.5 mm.

In the present invention, the composite lining structure after the hollowing treatment of the lining comprises a lining, a grouting hole, a grouting pipe, a foam concrete layer and a waterproof mortar column, wherein the lining has a grouting hole and an inner diameter of the grouting hole is 30 -50cm, the longitudinal spacing of the grouting holes is 2-5m, the circumferential spacing is 2-5m, and the grouting pipe is provided in the grouting hole. The length of the grouting pipe entering the cavity is 1-4m, and the outer diameter of the grouting pipe The thickness of the grouting pipe is 2-5 mm, the grouting hole is sealed with the grouting pipe, the outer side of the lining is a foam concrete layer, and the grouting pipe is a waterproof mortar column.

Further, when the cavity behind the lining is in the large collapse section, the height of the dome filled with the foam concrete layer when the cavity is filled is not less than 2 m; when the cavity behind the lining is in other sections, the height of the dome filled with the foam concrete layer when the cavity is filled is not more than 1 m.

Furthermore, when the cavity behind the lining is in the large collapse section, the minimum height of the dome-filled foam concrete layer when the cavity is filled is 3.5 m; when the cavity behind the lining is in other sections, the maximum height of the dome-filled foam concrete layer when the cavity is filled is 1m.

In the present invention, the large collapse section refers to a section of the tunnel where the length of the tunnel collapse exceeds 5 m, the height of the collapsed cavity exceeds 3 m, or a section of a tunnel where a large amount of water or mud is present in the tunnel.

In the present invention, monitoring should be strengthened during the infusion process, and temporary support should be strengthened when necessary. When abnormal conditions such as stringing, plugging drainage system, surrounding rock or lining deformation, and polluted water source occur, the following measures can be taken:

(1) Reduce the perfusion pressure or use intermittent perfusion.

(2) Change the infusion material or adjust the slurry gel time.

(3) Stop perfusion and adjust the perfusion protocol.

The present invention has the following advantages over the prior art:

The invention can effectively fill the tunnel collapse cavity. In the invention, the foam concrete is developed for the corrosion medium in the tunnel environment mainly for the sulfate, which greatly reduces the crystallized erosion effect of the sulfate on the foam concrete, and the foam concrete of the invention The self-weight is light, can reduce the tunnel lining load, has good durability, and is non-polluting. The material is consolidated well, does not lose, and the surface is rough, and the original contact surface is bonded well to ensure the safety of the tunnel.

DRAWINGS

The accompanying drawings, which are incorporated in the claims of the claims In the drawing:

Figure 1 is a schematic view of the structure of the large collapse section after the completion of the hollow construction behind the lining;

Figure 2 is a schematic view of the structure after the completion of the hollow construction behind the lining for the general paragraph.

Wherein, the above figures include the following reference numerals:

1. Lining, 2. Grouting hole, 3. Grouting pipe, 4. Foam concrete layer, 5. Waterproof mortar column.

Detailed ways

The invention will be further described in conjunction with the specific embodiments, and the advantages and features of the invention will become more apparent. However, the examples are merely exemplary and do not constitute any limitation on the scope of the invention. It should be understood by those skilled in the art that the details and the details of the present invention may be modified or substituted without departing from the spirit and scope of the invention.

Embodiment 1 The construction method of the cavity behind the tunnel lining is as follows:

(1) drilling the slurry hole on the lining surface, the inner diameter of the grouting hole is 40 cm, the longitudinal spacing of the grouting hole is 3 m, and the circumferential spacing is 3.5 m;

(2) Install a grouting pipe in the grouting hole. The outer diameter of the grouting pipe is 40cm, the thickness of the grouting pipe is 3.5mm, the length of the grouting pipe into the back of the lining is 3.5m, and the grouting hole and grouting are sealed. The gap between the tubes;

The raw material composition of the foam concrete is 245 parts by weight, 2.1 parts of crack resistant fiber, 2.4 parts of coagulant, 16.5 parts of foaming agent, 6 parts of foam stabilizer, 0.7 parts of dispersible polymer powder, 125 parts of water;

The cement is a Portland cement, the coagulant is calcium chloride, the foaming agent is an anionic surfactant and the protein foaming agent is mixed at a mass ratio of 1:1, and the composite foaming agent is stabilized. The foaming agent is sodium carboxymethyl cellulose, and the redispersible powder is vinyl acetate and ethylene copolymer resin;

The process for preparing the above foam concrete is as follows:

The perfusion pressure is 0.6 MPa;

Embodiment 2 The construction method of the cavity behind the tunnel lining is as follows:

(1) drilling a slurry hole in the lining surface, the inner diameter of the grouting hole is 32 cm, the longitudinal spacing of the grouting hole is 4 m, and the circumferential spacing is 2.5 m;

(2) Install a grouting pipe in the grouting hole. The outer diameter of the grouting pipe is 31.5cm, the thickness of the grouting pipe is 3mm, the length of the grouting pipe into the back of the lining is 2m, and the grouting hole and the grouting pipe are sealed. The gap between them;

The raw material composition of the foamed concrete is 210 parts by weight, 1.6 parts of crack resistant fiber, 2.1 parts of coagulant, 11 parts of foaming agent, 8 parts of foam stabilizer, 0.6 parts of dispersible polymer powder, 115 parts of water;

The process for preparing the above foam concrete is as follows:

The perfusion pressure is less than or equal to 0.4 MPa;

During the construction process, in the step (1), when the drilling hole is easy to collapse, the process of drilling with the pipe is adopted; in the step (3), when the groundwater is enriched and there is water pressure, the drainage hole is first set. Drain and then infuse.

After testing, the foam concrete of the invention has light weight, can reduce tunnel lining load, has good durability, is non-polluting, has good material consolidation, no loss, and rough surface.

Embodiment 3 composite lining structure after hollowing treatment behind lining

As shown in FIG. 1 and FIG. 2, the composite lining structure comprises a lining 1, a grouting hole 2, a grouting pipe 3, a foam concrete layer 4 and a waterproof mortar column 5, wherein the lining 1 is provided with a grouting hole 2, and grouting The inner diameter of the hole 2 is 40 cm, the longitudinal spacing of the grouting hole 2 is 3 m, and the circumferential spacing is 3.5 m. The grouting hole 2 is provided with a grouting pipe 3, and the length of the grouting pipe 3 into the cavity is 3.5 m, grouting The outer diameter of the pipe 3 is 40cm, the thickness of the grouting pipe is 3.5mm, the grouting hole 2 is sealed with the grouting pipe 3, the outer side of the lining 2 is a foam concrete layer 4, and the grouting pipe 3 is a waterproof mortar column 5;

When the cavity behind the lining is in the large collapse section, the minimum height of the dome-filled foam concrete layer 4 when the cavity is filled is 3.5 m; when the cavity behind the lining is in other sections, the maximum height of the dome-filled foam concrete layer 4 when the cavity is filled is 1 m.

Test Example 1 Corrosion of the foamed concrete of the present invention was measured when the corrosive medium was sulfate

When the concentration of sulfate is 500 mg/L, the corrosion strength of the foamed concrete of the present invention is weak.

The corrosion strength of the foaming coagulation in Application No. 201610314601.9 is strong.

Claims

A construction method for a cavity behind a tunnel lining, characterized in that the steps of the construction method are as follows:

(1) drilling the slurry hole on the lining surface, the inner diameter of the grouting hole is 30-50cm, the longitudinal spacing of the grouting hole is 2-5m, and the circumferential spacing is 2-5m;

(2) Install a grouting pipe in the grouting hole. The outer diameter of the grouting pipe is 30-50cm, the thickness of the grouting pipe is 2-5mm, and the length of the grouting pipe entering the back of the lining is 1-4m, sealing grouting a gap between the hole and the grouting pipe;

(3) injecting foam concrete into the cavity behind the lining through a grouting pipe to form a buffer layer;

The raw material composition of the foamed concrete is 200-300 parts of cement, 1.5-3 parts of crack-resistant fiber, 2-3 parts of coagulant, 10-20 parts of foaming agent, and foam stabilizer 5-10. Parts, dispersible latex powder 0.5-1 parts, water 100-140 parts;

The process for preparing the above foam concrete is as follows:

1 mixing cement, anti-cracking fiber, dispersible polymer powder and water to prepare an intermediate slurry;

2 adding a coagulant, a foaming agent and a foam stabilizer to the intermediate slurry to obtain a foamed concrete;

The perfusion pressure is 0.2-1.0 MPa;

During perfusion construction: firstly inject the left and right arch portions of the longitudinal 20m section, and the slurry flows out to the adjacent perfusion pipe. After the foamed concrete does not flow, the arched infusion is performed;

(4) For the large collapse section, the height of the dome filled foam concrete when the cavity is filled is not less than 2m, in order to effectively reduce the impact of the falling rock on the lining of the cavity and ensure the safety of the lining structure; in other paragraphs, the dome is filled with foam concrete when the cavity is filled. The height is not more than 1m;

(5) The grouting pipe is sealed and compacted with waterproof mortar, and the surface is flush with the lining.
The construction method according to claim 1, wherein the inner diameter of the grouting hole in the step (1) is 40 cm, the longitudinal spacing of the grouting holes is 3 m, and the circumferential spacing is 3.5 m.
The construction method according to claim 1, characterized in that in the step (2), the length of the grouting pipe into the cavity is 3.5 m, the outer diameter of the grouting pipe is 40 cm, and the thickness of the grouting pipe is 3.5 mm.
The construction method according to claim 1, wherein the raw material composition of the foamed concrete in the step (3) is 245 parts by weight of cement, 2.1 parts of crack-resistant fiber, 2.4 parts of coagulant, and hair. 16.5 parts of foaming agent, 6 parts of foam stabilizer, 0.7 parts of dispersible polymer powder, and 125 parts of water;

The cement is a Portland cement, the coagulant is calcium chloride, the foaming agent is an anionic surfactant and the protein foaming agent is mixed at a mass ratio of 1:1, and the composite foaming agent is stabilized. The foaming agent is sodium carboxymethylcellulose, and the redispersible latex powder is a vinyl acetate and ethylene copolymer resin.
The construction method according to claim 1, wherein the pouring pressure in the step (3) is 0.6 MPa.
A composite lining structure, characterized in that the composite lining structure is obtained by using a construction method according to any one of claims 1 to 5 to treat a hollow behind the lining, and the composite lining structure comprises a lining, a grouting hole and a grouting Tube, foam concrete layer and waterproof mortar column, the lining is provided with a grouting hole, the inner diameter of the grouting hole is 30-50cm, the longitudinal spacing of the grouting hole is 2-5m, and the circumferential spacing is 2-5m, note There is a grouting pipe in the slurry hole. The length of the grouting pipe entering the cavity is 1-4m, the outer diameter of the grouting pipe is 30-50cm, the thickness of the grouting pipe is 2-5mm, and the grouting hole and the grouting pipe are sealed. The outer side of the lining is a foam concrete layer, and the grouting pipe is a waterproof mortar column.
The composite lining structure according to claim 6, wherein when the cavity behind the lining is in a large collapse section, the height of the dome filled with the foam concrete layer when the cavity is filled is not less than 2 m; when the cavity behind the lining is in other sections, when the cavity is filled The height of the dome filled foam concrete layer is not more than 1 m.
The composite lining structure according to claim 6, wherein the inner diameter of the grouting hole is 40 cm, the longitudinal spacing of the grouting holes is 3 m, and the circumferential spacing is 3.5 m; the length of the grouting tube entering the cavity is 3.5. m, the outer diameter of the grouting pipe is 40 cm, and the thickness of the grouting pipe is 3.5 mm.
The composite lining structure according to claim 7, characterized in that, when the cavity behind the lining is in a large collapse section, the minimum height of the dome-filled foam concrete layer when the cavity is filled is 3.5 m.
The composite lining structure according to claim 7, wherein the maximum height of the dome-filled foam concrete layer is 1 m when the cavity behind the lining is in other sections.