阅读说明：本技术 一种隧道建养一体化冻害-水害防控方法 (Integrated freezing injury-water injury prevention and control method for tunnel construction and maintenance ) 是由 凌贤长 于源 韩笑 马朋辉 于 2021-09-17 设计创作，主要内容包括：一种隧道建养一体化冻害-水害防控方法,属于隧道工程施工技术领域,具体方案包括以下步骤：步骤一、利用超前探孔技术准确探测软岩地质情况和地下水发育情况；步骤二、依据超前探孔探测结果对富水地段采取超前钻孔泄水降压；步骤三、对超前小导管注浆堵水、加固围岩；步骤四、开挖、施做初期支护结构；步骤五、初期支护施做完毕后施作径向小导管；步骤六、开挖仰拱并浇筑仰拱混凝土；步骤七、施作二次衬砌。本发明解决了极端冻融区高富水软岩山岭隧道由于地下水、软岩岩性给施工带来的影响,有效控制了高富水冻融环境下给隧道带来的危害及破坏,降低了冻融因素对隧道施工及运营期的影响。(A tunnel construction and maintenance integrated freezing damage-water damage prevention and control method belongs to the technical field of tunnel engineering construction, and the specific scheme comprises the following steps: the method comprises the following steps of firstly, accurately detecting soft rock geological conditions and underground water development conditions by utilizing a pilot hole detection technology; step two, adopting advanced drilling to drain water and reduce pressure for the water-rich area according to the advanced hole detection result; grouting the leading small guide pipe to block water and reinforce the surrounding rock; excavating and constructing a primary supporting structure; step five, constructing a radial small conduit after finishing the construction of the primary support; excavating an inverted arch and pouring inverted arch concrete; and seventhly, constructing a secondary lining. The method solves the problem that the construction of the high water-rich soft rock mountain tunnel in the extreme freezing and thawing area is influenced by the properties of underground water and soft rock, effectively controls the damage and destruction of the tunnel in the high water-rich freezing and thawing environment, and reduces the influence of freezing and thawing factors on the tunnel construction and operation period.)

1. A tunnel construction and maintenance integrated freezing damage-water damage prevention and control method is characterized by comprising the following steps:

the method comprises the following steps of firstly, accurately detecting soft rock geological conditions and underground water development conditions in the excavation contour line (4) of the tunnel along the excavation direction of the tunnel by using a pilot hole detection technology;

secondly, according to the advanced hole probing result, performing advanced drilling drainage and pressure reduction on the water-rich section along the excavation direction of the tunnel;

step three, uniformly distributing and constructing advanced small guide pipes (3) along the outer part of a tunnel excavation contour line (4) in the range of 120-140 degrees of the arch part of the tunnel body, grouting the advanced small guide pipes, blocking water and reinforcing surrounding rocks;

excavating and constructing a primary supporting structure;

step five, after the primary support construction is finished, arranging the primary support along the circumferential direction of a tunnel excavation contour line (4), and constructing a radial small guide pipe (5) perpendicular to the excavation direction of the tunnel;

excavating an inverted arch and pouring inverted arch concrete;

and seventhly, constructing a secondary lining.

2. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: in the first step, the lithology and structural characteristics of the soft rock are accurately judged through core sampling, and the development condition and the water pressure condition of underground water are accurately judged through water yield of the exploration holes.

3. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: in the first step, when underground water is detected by using a pilot hole detection technology, an ice-containing condition of soft rock is detected by using an ultrasonic ice detection technology, and if ice is contained, deicing, grouting, plugging and crack stopping are carried out.

4. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: in the first step, the advanced exploring hole is drilled by a drilling machine with a drill bit with the diameter of phi 100-phi 120mm, the drilling is carried out once every 45-55m, and the drilling is carried out for 50-60m every time, so that the purpose of continuous exploration is achieved.

5. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: and step two, constructing a deep-buried drainage ditch under the tunnel, designing the depth of the ditch by combining the water level and water content detected in advance, and draining the drained water to avoid the icing of the drained water.

6. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: and in the second step, the drain hole (2) for draining and depressurizing the advanced drilling hole is drilled by a drilling machine with a drill bit of phi 85-phi 95mm, and the hole is drilled every 25m and the drilling depth is 30m until the water-rich band penetrates through the whole water-rich band.

7. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: and step three, the external insertion angle of the advanced small catheter (3) is 10-30 degrees, the length is 4-6m, and the circumferential distance is 1-2 m.

8. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: and step three, the water plugging and grouting range is larger than the freezing depth.

9. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: in the fifth step, the length of the small radial guide pipe (5) is 5-6m, and the distance is 0.5-1 m.

10. The method for preventing and controlling freezing injury-water injury in tunnel construction and cultivation integrated according to claim 1, wherein: and fifthly, if the primary support structure is deformed and cracked or before secondary lining is applied, radial grouting can be performed through the small radial guide pipes (5) to reinforce the surrounding rock and block water again, and the back of the lining is prevented from being hollow.

Technical Field

The invention belongs to the technical field of tunnel engineering construction, and particularly relates to a freeze injury-water injury prevention and control method for tunnel construction and maintenance.

Background

Compared with the general rock mass, the soft rock mountain tunnel has the advantages that the rock mass joints and cracks of the soft surrounding rock are broken, the strength is low, the self stability of the surrounding rock is poor, in addition, if the soft rock mountain tunnel is located in a high water-rich area with rich underground water, the soft rock is easy to soften and disintegrate when meeting water, when the tunnel penetrates the high water-rich soft rock in the construction period, engineering accidents such as large deformation, tunnel face collapse, water bursting and mud bursting, difficult control of excavation profiles, damage of a supporting structure, steel frame distortion, cracking of a lining and the like are easy to occur, in addition, if the water-rich area has confined water and no reasonable targeted construction scheme is available in construction, the danger is greater, grout is washed away when being not solidified unequally during grouting, sprayed concrete is washed away when being gelled unequally and the like, and the like. Particularly, in an extreme freezing and thawing area, in addition to the possible engineering accidents, water seepage and ice hanging often occur during the construction of a tunnel on a mountain with high water-rich soft rock, underground water can seriously affect the maintenance of concrete during the construction of a tunnel lining under the freezing and thawing environment, if no special measures are taken for the underground water during the construction, seepage can also occur during the operation of the tunnel, so-called 'nine leakages in ten tunnels', the seepage of the underground water in surrounding rocks can cause water accumulation on the road surface in the tunnel, great potential safety hazards are brought to driving, and the seepage of the tunnel in the extreme freezing and thawing area can cause a series of freezing damage problems such as frost heaving and cracking, deformation, reduction of bearing capacity and the like of the lining concrete due to freezing and thawing circulation.

At present, during construction of a tunnel in a mountain of a soft rock with high water content in an extremely freezing and thawing area, due to the fact that actual characteristics of the soft rock are not deeply known, and meanwhile, underground water, particularly confined water, is not detected sufficiently in the excavation and tunneling process, no reasonable targeted scheme exists, so that engineering accidents such as deformation, slipping, water inrush and mud inrush, difficulty in control of excavation outline, damage of a supporting structure, steel frame distortion and fracture, lining cracking, water seepage and ice hanging and the like are caused very easily, and great hidden danger is brought to the service operation period of the tunnel.

Disclosure of Invention

The invention aims to solve the problems existing in the construction period of a soft rock mountain tunnel in a high water-rich area of an extreme freezing and thawing area, comprehensively analyze and consider the advantages and the defects existing in the prior construction technology, and provide a method for preventing and controlling freezing damage and water damage by integrating tunnel construction and maintenance.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

accurately detecting soft rock geological conditions and underground water development conditions in the excavation contour line of the tunnel along the excavation direction of the tunnel by using a pilot hole detection technology;

secondly, according to the advanced hole probing result, performing advanced drilling drainage and pressure reduction on the water-rich section along the excavation direction of the tunnel;

step three, uniformly distributing and constructing advanced small ducts along the outer part of a tunnel excavation contour line in the range of 120-140 degrees of the arch part of the tunnel body, grouting and plugging water for the advanced small ducts, and reinforcing surrounding rocks;

excavating and constructing a primary supporting structure;

step five, after the primary support is finished, arranging the primary support along the circumferential direction of the tunnel excavation contour line, and constructing a small radial conduit perpendicular to the excavation direction of the tunnel;

excavating an inverted arch and pouring inverted arch concrete;

and seventhly, constructing a secondary lining.

Compared with the prior art, the invention has the beneficial effects that:

1. the method adopts a 'probing-draining-injecting-blocking-dredging' combined water stopping construction technical method, effectively controls the damage and destruction of underground water, particularly confined water, of a high water-rich area to the construction of a soft rock tunnel, and also improves the maintenance environment of lining concrete after water control in an extremely freezing and thawing area.

2. According to the environmental characteristics of an extreme freezing and thawing area, ultrasonic ice detection is carried out before excavation, and if ice content reaches a certain amount, grouting reinforcement treatment is carried out firstly by adopting a patent 'system and method for removing ice, grouting and crack arrest of tunnel surrounding rock cracks in a freezing and thawing area', so that collapse caused by thawing is avoided.

3. When water is drained, a deep-buried drainage ditch is constructed under the tunnel and used for draining the drained water so as to avoid the drained ice.

4. By considering the construction step sequence, the surrounding rock stress can be borne by advancing the small guide pipe grouting, the lining is carried out after the hydrophobic effect is realized, and the maintenance environment of the lining is improved.

5. The freezing influence is considered, the freezing depth is analyzed in advance, the range of the grouting ring is determined by the freezing depth, water outside the ring is blocked, meanwhile, the freezing depth after grouting is considered, the cost can be saved by determining the grouting ring, and the water plugging grouting range is larger than the calculated freezing depth.

6. The grouting material is added with a proper amount of gypsum for heat preservation, so that the freezing depth can be reduced, and the manufacturing cost is reduced.

7. Aiming at the characteristics of soft rock, the surrounding rock is reinforced by adopting advanced small conduit grouting and small conduit radial grouting, the rock mass structure is improved, and the self-stability of the soft surrounding rock is improved.

8. The small radial guide pipes are used as drainage channels for drainage in the early stage, the damage effect of underground water, particularly pressure-bearing water, on primary support is relieved, and meanwhile, if the primary support structure deforms and cracks or before secondary lining is applied, radial grouting can be performed through the small radial guide pipes to reinforce surrounding rocks and block water again, and the back of the lining is prevented from being hollowed.

Drawings

FIG. 1 is a schematic view of a lead probe hole and bleed hole arrangement;

FIG. 2 is a schematic view of a lead microcatheter arrangement;

FIG. 3 is a schematic view of a leading microcatheter configuration;

FIG. 4 is a schematic view of a radial microcatheter arrangement;

wherein, 1 is a leading detection hole; 2 is a water drainage hole; 3 is a small advanced catheter; 4, tunnel excavation contour lines; 5 is a small radial catheter; 31 is a tip; 32 is a mud jacking hole; and 33 is a pipe clamp.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to fig. 1-4 and specific embodiments, and it is obvious that the described embodiments are only a part of embodiments of the invention, rather than all embodiments, and all other embodiments obtained by those skilled in the art without creative efforts based on the embodiments in the present invention belong to the protection scope of the present invention.

Detailed description of the invention

The invention aims to solve the problem that the rocky property of underground water and soft rock of a high water-rich soft rock mountain tunnel in an extreme freezing and thawing area brings influence to construction, and provides a tunnel construction and maintenance integrated freezing injury-water injury prevention and control method, which effectively controls the damage and destruction to the tunnel in a high water-rich freezing and thawing environment, adopts a small-duct advanced grouting and small-duct radial grouting mode according to the rocky property characteristics of soft surrounding rock, accurately controls the grouting range, effectively reduces the influence of surrounding rock water on lining in the freezing and thawing environment, improves the lining concrete maintenance condition, avoids freezing and thawing diseases of a support system, achieves the purposes of water control and soft rock reinforcement integrally, and further reduces the influence of freezing and thawing factors on tunnel construction and operation period.

A tunnel construction and maintenance integrated freezing injury-water injury prevention and control method is characterized in that 'exploration' refers to advanced detection, soft rock geological conditions and underground water development conditions are accurately detected by using an advanced hole probing technology, specifically, the soft rock lithology and structural characteristics are accurately judged by core sampling, the underground water development conditions and the water pressure conditions are accurately judged by using the water yield of a probing hole, an ultrasonic ice probing technology is adopted to detect the ice-containing conditions of soft rock while underground water is detected by using the advanced hole probing technology, and if ice is contained, a patent 'system and method for deicing, grouting and crack stopping of tunnel surrounding rock cracks in a seasonal freezing region' is adopted for processing; the drainage refers to draining and pressure reduction of the advanced drilling, the draining and pressure reduction of the advanced drilling is adopted for the water-rich area according to the detection result of the advanced drilling, and meanwhile, a deep-buried drainage ditch is constructed under the tunnel and used for draining and dredging the drained water to avoid icing; the 'injection' and 'blocking' refer to the injection and water blocking of the small guide pipes ahead and the reinforcement of surrounding rocks; the first dredging means that a deep-buried drainage ditch is formed under the tunnel before water drainage for draining water to avoid freezing of the drained water, the second means that a grouting ring formed after grouting can play a role in drainage, and the third means that after primary support construction is finished, the constructed radial small conduit can be used as a drainage channel to drain water in the early stage, so that the damage of underground water, particularly pressure-bearing water, to the primary support is relieved.

The technical scheme of the invention comprises the following specific steps:

the method comprises the following steps: before the excavation of the tunneling tunnel, geological data provided by design are carefully analyzed, and soft rock level in front of the tunnel face and underground water development condition are preliminarily judged, so that guidance suggestions are provided for advanced drilling.

Step two: the soft rock geological condition and the underground water development condition are accurately detected by utilizing a pilot hole detection technology: the lithology and the structural characteristics of the soft rock are accurately judged through core sampling, the development condition and the water pressure condition of underground water are accurately judged through the water yield of the exploring hole, the advancing exploring hole is drilled by a drilling machine with the diameter of 100-120 mm, and the drilling is carried out once every 45-55m and is about 50-60m every time. The method is characterized in that when underground water is detected by using a advanced hole detecting technology, an ultrasonic ice detecting technology is adopted to detect the ice-containing condition of soft rock aiming at the environmental characteristics of an extreme freezing and thawing area, and if ice is contained, deicing, grouting, blocking and crack stopping are carried out, the system and the method for deicing, grouting and crack stopping of tunnel surrounding rock cracks in a freezing area in China' patent application CN201711412048.3 can be adopted to carry out treatment, grouting and reinforcing treatment is carried out firstly, and collapse caused by melting is avoided.

Step three: and draining water and reducing pressure in the advanced drilling. And (3) according to the detection result of the advanced drilling, draining water from the water-rich section by the advanced drilling and depressurizing, wherein the advanced draining water adopts a drilling machine with a drill bit of phi 85-phi 95mm to drill holes, and the depth of the drilled hole is 30m when the hole is drilled every 25 m. Advanced survey hole 1 and outlet 2 arrange to see attached drawing 1 in detail, outlet 2 is a plurality of, sets up the inside circumference position at tunnel excavation contour line 4 along the excavation direction equipartition in tunnel, advanced survey hole 1 arranges in tunnel excavation contour line 4's inside and be located a plurality of outlet 2's middle part position, executes to bury the escape canal deeply under the tunnel simultaneously, combines the water level water content of advanced survey, designs the degree of depth of ditch for drainage of sluicing avoids the water that leaks to freeze.

Step four: the leading small conduit 3 is used for grouting, water plugging and surrounding rock reinforcement. The method is characterized in that advanced small guide pipes 3 are uniformly distributed along the outer part of a tunnel excavation contour line 4 within the range of 120-140 degrees (alpha angle) of an arch part of a tunnel body, the external insertion angle of the advanced small guide pipes 3 is 10-30 degrees, the length is 4-6m, the circumferential distance is 1-2m, the detailed description is shown in figure 2, the water plugging and grouting range is larger than the freezing depth, the freezing depth is analyzed in advance by considering freezing influence, the grouting ring range is determined by using the freezing depth to block water outside the ring, meanwhile, the freezing depth after grouting is considered, the cost of the grouting ring can be saved by determining the grouting ring, the water plugging and grouting range is larger than the calculated freezing depth, the figure 3 is a structural schematic diagram of the advanced small guide pipes 3, the front ends of the advanced small guide pipes 3 are provided with tip ends 31, the rear ends of the small guide pipes are provided with pipe hoops 33, and the side walls of the advanced small guide pipes are provided with a plurality of grouting holes 32. Preferably, the small advancing pipe 3 is a seamless steel pipe.

Step five: and excavating and constructing a primary supporting structure.

Step six: the method is characterized in that after the primary support is completely constructed, small guide pipes 5 are constructed, the radial small guide pipes 5 are 5-6m long and 0.5-1m apart from each other, the radial small guide pipes 5 are arranged along the circumferential direction of a tunnel excavation contour line 4 and perpendicular to the excavation direction of the tunnel, the radial small guide pipes 5 are used as drainage channels to drain water in the early stage, the damage effect of underground water, particularly pressure-bearing water, on the primary support is relieved, meanwhile, if the primary support structure deforms and cracks or is constructed before secondary lining, radial grouting is carried out on the radial small guide pipes 5 to reinforce surrounding rock and block water again, and the back of the lining is prevented from being hollow, and the method is detailed in figure 4.

Step seven: and excavating an inverted arch and pouring inverted arch concrete.

Step eight: and (5) constructing a secondary lining.

The invention provides a tunnel construction and maintenance integrated freezing injury-water injury prevention and control method, which solves the problem that a high water-rich soft rock mountain tunnel in an extreme freezing and thawing area has influence on construction due to the lithology of underground water and soft rock, effectively controls the damage and damage to the tunnel in a high water-rich freezing and thawing environment, adopts a small-conduit advanced grouting and small-conduit radial grouting mode aiming at the lithology characteristics of soft and weak surrounding rock, accurately controls the grouting range, effectively reduces the influence of surrounding rock water on lining in the freezing and thawing environment, improves the lining concrete maintenance condition, avoids freezing and thawing diseases of a support system, achieves the purposes of controlling water and reinforcing soft rock integrally, and further reduces the influence of freezing and thawing factors on the tunnel construction and operation period.

It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.