CN206308569U - It is a kind of to reinforce the road structure for punishing the solution cavity that underlies - Google Patents

Abstract

The utility model discloses a subgrade structure for strengthening and treating an underlying karst cave, which mainly includes a subgrade (1), a reinforced beam (2), a curtain grouting hole (3), a punching grouting pile (4), and a karst cave (6 ), the curtain reinforcement area (7), and the steel casing (8); the utility model first adopts the sleeve valve pipe grouting method to perform grouting reinforcement on the surrounding boundary of the karst cave (6) through the curtain grouting hole (3) to form a curtain The reinforcement area (7) cuts off the water flow to prevent seepage and plugging; then use different sizes of punching piles (4) to reinforce the karst cave (6), and steel casings are used in the karst cave (6) area (8) pouring; the top of the final punching cast-in-place pile (4) and the curtain grouting hole (3) after the grouting are connected by a reinforced crossbeam (2), forming a joint between the rigid pile and the reinforced beam above the pile top. A pile-net composite foundation is formed; the utility model can effectively treat large-scale karst caves with a buried depth greater than 10m under the roadbed, and can reinforce and protect the roadbed; the structure is not only convenient for construction, but also has a wide range of applications.

Description

A subgrade structure for strengthening and treating underlying karst caves

technical field

The utility model relates to the technical field of road engineering in civil engineering, in particular to a subgrade structure for strengthening and treating underlying karst caves.

Background technique

my country's geological conditions are complex, and karst is widely distributed. With the development of highway construction, it is inevitable that the highway route will pass through the karst development area. There are a large number of karst caves and soil caves in karst road sections, which will bring potential hazards to the construction and operation of road subgrades. Karst caves have become common adverse geological disasters in the process of highway construction in my country. The soluble rocks are dissolved under the action of water. Serious subsidence occurs, so it is imminent to solve the threat of mining karst caves to road construction.

At present, there are many ways to relieve the threat of karst caves to highway construction, which are mainly divided into two categories: grouting filling and pile foundation; grouting filling has a good effect on the stability of the roadbed and can maintain the stability of the entire roadbed, but its It is not suitable for large and deep karst caves, and the cost of grouting filling is expensive and the construction is complicated; pile foundation reinforcement can provide sufficient bearing capacity for the roadbed, and the position and spacing of the pile foundation play a key role in the stability of the roadbed, but for How to determine the position and spacing of pile foundations has not been uniformly certified. At the same time, the existing pile foundations are often unable to support the ever-expanding karst caves under the action of water erosion, and cannot guarantee the long-term stability of the subgrade.

Contents of the invention

Aiming at the above problems, the utility model discloses a subgrade structure for strengthening and treating the underlying karst caves. The following technical scheme is adopted: firstly, the curtain grouting method is used to reinforce the adjacent boundary of the karst caves to prevent the continuous expansion of the karst caves; Cast-in-place piles are used to reinforce the karst cave area, and when pouring punched-in-place piles in the karst cave area, parts of the piles are poured with steel casings, which can save a lot of grout and provide sufficient support for the top roadbed, and finally through reinforcement The crossbeam connects the punched cast-in-place piles and the poured curtain grouting holes to form a stable pile-net composite foundation to ensure the overall stability of the subgrade. This subgrade structure can effectively treat large-scale karst caves with a buried depth greater than 10m under the subgrade .

The roadbed structure for strengthening and treating the underlying karst cave is characterized in that the curtain grouting holes (3) are arranged in a circle and surround the entire karst cave, and the gap between adjacent curtain grouting holes (3) The distance d is 1.5m, and the distance D between the curtain grouting hole (3) and the surrounding edges of the cave (6) is not less than 1.5m.

The subgrade structure for strengthening and treating the underlying karst cave is characterized in that, when pouring the perforated piles (4) in the karst cave (6) area, steel casings (8) are used for pouring, and the distance between the steel casings (8) The upper and lower bottom of the karst cave (6) shall not be less than 0.5m, the grout shall be grouted with a strength not less than 32.5MPa, the water-cement ratio shall be 1:1.3~1:1.5, and the cement-water glass double grout shall be used for the curtain grouting hole, where the water glass modulus It is 2.4~3.4, and the concentration is above 50 degrees Baume.

The subgrade structure for strengthening and treating the underlying karst cave is characterized in that the lower ends of the curtain grouting holes (3) and the punching piles (4) are all lower than the bottom elevation of the karst cave by more than 0.5m.

The beneficial effects of the utility model: the curtain grouting method is used to reinforce the adjacent boundary of the karst cave, so as to cut off the water flow, achieve the purpose of preventing seepage and plugging, and at the same time prevent the karst cave from expanding; To provide sufficient bearing capacity, steel casings are used for pouring in the karst cave area, which can save a lot of grout; the punched cast-in-place piles and the poured curtain grouting holes are connected to each other through reinforced beams to form a stable pile-net composite foundation , to ensure the overall stability of its foundation and subgrade work area, the structure is not only simple in construction, economical and applicable, but also convenient in construction and wide in scope of application.

Description of drawings

Fig. 1 is the roadbed structure schematic diagram of the present utility model.

Fig. 2 is a top view of the laying structure of the present invention.

In the figure, 1—subgrade, 2—reinforced beam, 3—curtain grouting hole, 4—punched cast-in-place pile, 5—large-sized punched cast-in-place pile, 6—karst cave, 7—curtain reinforcement area, 8—steel Casing.

detailed description

Below in conjunction with the accompanying drawings, the structural combination and implementation steps of the present utility model will be further described.

As shown in Figure 1 and Figure 2, they are the front view and top view of the utility model roadbed structure respectively, which mainly include roadbed (1), reinforced beam (2), curtain grouting hole (3), punching cast-in-place pile (4) ), large-size perforated piles (5), karst caves (6), and steel casings (8); the underside of the subgrade (1) is interlacedly connected by reinforced beams (2), and the reinforced beams (2) They are all connected to each other with punching cast-in-place piles (4) and cast-in-place curtain grouting holes (3), and sleeve valve pipes are used for curtain grouting around the boundary of the karst cave (6).

1. Firstly, various survey methods such as geological radar method, high-density electrical method, and engineering geological drilling are used to determine the size and scope of the karst cave, so as to determine which method to use to solve the problem of the hazard of the karst cave to the subgrade.

2. According to the size and scope of the karst cave, if it is a large karst cave with a buried depth greater than 10m under the roadbed, the roadbed structure can be used to design and plan the positions of the punching piles and curtain grouting holes (3) on the road surface, and use a drilling machine Create relief holes in the cave area.

3. The construction site shall be leveled in advance, and trenches and sumps shall be excavated along the drilling position. During grouting construction, an automatic flow and pressure recorder shall be used, and curtains with a distance of d of 1.5m shall be arranged at the critical edge of the cave. Grouting hole (3), construct two rows of grouting holes, and initially plan to inject grouting twice, the first grouting pressure is controlled at 0.3MPa, and the second grouting pressure is controlled at 0.8~1MPa to form a grouting curtain.

4. The grouting in the karst cave area shall be constructed by jumping holes at intervals from all sides to the inside. When pouring in the karst cave area, steel casings shall be used for pouring in sections. The pouring depth shall be at least 0.5m lower than the elevation of the bottom of the karst cave, and it shall be arranged in a plum blossom pattern.

5. After the grouting is completed, the punched cast-in-situ pile (4) and the grouted curtain grouting hole (3) are bound and poured through the reinforced beam (2), and the reinforced beam (2) is made of prestressed pouring . The content not described in detail in this specification belongs to the prior art known to those skilled in the art.

Claims (4)

1. the road structure of the solution cavity that underlies is punished in a kind of reinforcing, including：Roadbed (1), reinforcement crossbeam (2), curtain-grouting hole (3), Punching Borehole Cast-in-place Concrete Pile (4), solution cavity (6), steel pile casting (8)；It is characterized in that, described roadbed (1) is noted by the curtain after slip casting Slurry hole (3) and Punching Borehole Cast-in-place Concrete Pile (4) are connected with each other by reinforcement crossbeam (2), and described curtain-grouting hole (3) top and punching are filled Note stake (4) top keeps concordant, and its lower curtate is below solution cavity elevation of bottom, and described curtain-grouting hole (3) is positioned at solution cavity (6) Close on borderline region.

2. the road structure of the solution cavity that underlies is punished in a kind of reinforcing according to claim 1, it is characterized in that, described curtain note Slurry hole (3) circular arrangement, and it is 1.5m, curtain-grouting to surround the distance between whole solution cavity, adjacent curtain-grouting hole (3) d Hole (3) is not less than 1.5m away from solution cavity (6) edge apart from D.

3. the road structure of the solution cavity that underlies is punished in a kind of reinforcing according to claim 1, it is characterized in that, described curtain note Slurry hole (3) circular arrangement, and it is 1.5m, curtain-grouting to surround the distance between whole solution cavity, adjacent curtain-grouting hole (3) d Hole (3) is not less than 1.5m away from solution cavity (6) edge apart from D.

4. the road structure of the solution cavity that underlies is punished in a kind of reinforcing according to claim 1, it is characterized in that, curtain-grouting hole And the low side of Punching Borehole Cast-in-place Concrete Pile (4) is below more than solution cavity elevation of bottom 0.5m (3).