阅读说明：本技术 一种空洞塌陷防治结构及施工方法 (Cavity collapse prevention and control structure and construction method ) 是由 邱成春 徐桂中 宋苗苗 张丹 顾国庆 刘振建 孙嘉泽 葛骏 陈少波 于 2020-06-23 设计创作，主要内容包括：本发明涉及一种空洞塌陷防治结构及施工方法,在地下空洞塌陷区的上方架设防治结构,防治结构包括铺设在地下空洞塌陷区上方的土工织物,在土工织物上设置加筋空间体,且土工织物将加筋空间体整体包裹形成包裹结构,在包裹结构的顶端预设若干泵送管道入口；防治结构还包括防护结构,其设置在包裹结构的上方；加筋空间体包括土工格栅、土工格室由下至上交错叠加铺设形成；本发明不仅可以同时防治大跨度、小跨度空洞塌陷问题,而且能够降低施工成本,兼具经济性。(The invention relates to a cavity collapse prevention and treatment structure and a construction method, wherein the prevention and treatment structure is erected above an underground cavity collapse area and comprises a geotextile laid above the underground cavity collapse area, a reinforced space body is arranged on the geotextile, the geotextile integrally wraps the reinforced space body to form a wrapping structure, and a plurality of pumping pipeline inlets are preset at the top end of the wrapping structure; the control structure also comprises a protective structure which is arranged above the wrapping structure; the reinforced space body comprises a geogrid and geocell chambers which are formed by staggered, overlapped and laid from bottom to top; the invention can not only prevent and treat the problem of cavity collapse of large span and small span, but also reduce the construction cost and has economical efficiency.)

1. The utility model provides a cavity prevention and cure structure that collapses, includes the underground cavity district that collapses which characterized in that: erecting a prevention structure above the underground cavity collapse area;

the prevention and control structure comprises geotextile laid above an underground cavity collapse area, a reinforced space body is arranged on the geotextile, the geotextile integrally wraps the reinforced space body to form a wrapping structure, and a plurality of pumping pipeline inlets are preset at the top end of the wrapping structure;

the control structure also comprises a protective structure which is arranged above the wrapping structure;

the reinforced space body comprises a geogrid and geocell chambers which are formed by staggered, overlapped and laid from bottom to top.

2. The structure for preventing and treating cavity collapse according to claim 1, wherein:

the geogrid comprises a plurality of geogrid transverse ribs and a plurality of geogrid longitudinal ribs which are connected in a crisscross mode; the cross joints of the transverse ribs and the longitudinal ribs of the geogrid form cross joints, and reinforcing nodes are arranged on the surfaces of the cross joints or the bottom surfaces of the cross joints or the surfaces and the bottom surfaces of the cross joints.

3. The structure for preventing and treating cavity collapse according to claim 1, wherein:

the geocell comprises a plurality of wavy geocells, the geocells are located on the same plane, and adjacent geocells are connected at the bending position.

4. The structure for preventing and treating cavity collapse according to claim 3, wherein: and a plurality of holes are uniformly formed on the earthwork lattice bars.

5. The structure for preventing and treating cavity collapse according to claim 1, wherein: the protective structure is a balloon, the surface of the balloon is of an arc-shaped structure, the bottom of the balloon is flat, and the balloon is attached to the top of the reinforced spatial body.

6. The structure for preventing and treating cavity collapse according to claim 1, wherein: and a plurality of deformation acquisition alarm systems are arranged at the bottom of the geotextile.

7. A construction method of a cavity collapse prevention structure based on any of the above claims, characterized in that: the method specifically comprises the following steps:

the first step is as follows: manufacturing geogrids, namely fixedly connecting a plurality of geogrid transverse ribs and a plurality of geogrid longitudinal ribs in a crisscross manner to form the geogrids, and installing reinforcing nodes on the surfaces or the bottoms of cross-shaped intersection points or installing the reinforcing nodes on the surfaces and the bottom surfaces of the intersection points at the same time;

the second step is that: manufacturing a geocell, placing the surfaces of a plurality of wavy geocell strips vertical to the ground, arranging the plurality of geocell strips in parallel, and binding the bending parts of the adjacent geocell strips;

the third step: laying geotextile on the surface of the underground cavity collapse area, overlapping the geotextile in a staggered manner according to the sequence of geogrids and geocells, wherein the geogrids and the geocells are connected by binding, and the overlapped height meets the filling height and design requirements of the embankment;

the fourth step: after the geogrid and the geocell are overlapped in a staggered mode, a reinforced spatial body is formed, geotextile is wrapped around the reinforced spatial body, the top of the reinforced spatial body is sewn to form a wrapping structure, a plurality of pumping pipeline inlets are reserved at the top of the sewn wrapping structure, and a plurality of deformation acquisition alarm systems are installed at the bottom of the geotextile;

the fifth step: filling embankment filler around the reinforced space body until the filler reaches the top elevation of the reinforced space body, starting a pump to convey the flowing solidified waste mud to the reinforced space body, and forming a rigid body similar to the reinforced concrete beam by the solidified waste mud and the reinforced space body;

and a sixth step: placing a balloon at the top of the reinforced spatial body, enabling connecting pipelines on two sides of the balloon to extend out of an embankment side slope, then continuously filling embankment filler at the top of the balloon until the embankment filler reaches a design height, after a local cavity collapse area collapses, enabling the bottom of the geotextile wrapping layer to deform or tear, triggering a deformation acquisition alarm system, injecting liquid or gas into the balloon through a pipeline at the moment, and forming an arch shape on the surface of the balloon.

Technical Field

The invention relates to a cavity collapse prevention and control structure and a construction method, and belongs to the technical field of geotechnical reinforcement and foundation treatment.

Background

The generation of the underground cavity comprises two factors of nature and/or human activities, the natural factors mostly occur in karst areas, for example, the limestone or dolomite bedrock is dissolved to form the underground cavity, and the loose soil stratum is easy to form the cavity under the conditions of underground water scouring and undermining; the human factors are mainly underground resource exploitation and underground engineering construction, and cavities are formed in the stratum. The existence of the underground cavity brings great potential safety hazards to engineering construction and operation, for example, the local subsidence of a lower lying soil body can cause the stretching damage of a geosynthetic material in the composite liner system to cause the failure of an anti-seepage function, thereby causing serious pollution to the surrounding environment; tunnel and mine tunnel cause huge life and economic loss due to collapse disaster; when a highway is constructed in a karst development area, roadbed destruction is caused by soil cave collapse, and local surface subsidence is induced to happen occasionally. At present, a plurality of karst soil hole treatment methods mainly comprise a filling method, a rigid body crossing method, a hole internal support method, a dynamic compaction method and the like, but the methods are all established on the basis of completely exploring the space distribution and the hydrogeological conditions of the karst soil holes, which is exactly the difficult way of the current karst soil hole exploration means; with the large-scale growth of infrastructure, structures such as roads are inevitably built on the ascertained holes or holes which may be formed after construction, so that the roads are always exposed to the risk of local collapse, which makes the traffic safety very challenging.

With the development of geosynthetics, because of convenient installation, short construction period, low engineering construction cost and limited influence on the environment, horizontal reinforcement methods are commonly used in road engineering at home and abroad to prevent or delay the sudden damage of roadbeds caused by cavity settlement. Geosynthetics such as geogrids, geonets and geotextiles can reinforce the top plate soil body above the cavity or the adjacent road subgrade, so that the differential settlement and the lateral deformation of the embankment are effectively reduced; when the soil layer of the top plate of the cavity is small in thickness and the span of the cavity is not large, the horizontal reinforcement body can prevent the embankment from collapsing; however, when the span of the lower horizontal cavity is large, the geosynthetic material is flexible and the anchoring length is insufficient, so that the reinforced body cannot completely prevent and control the deformation of the roadbed caused by the collapse of the cavity, but the settlement and instability of the roadbed are gradually evolved, so that the early warning effect can be achieved, and the occurrence of traffic accidents and the casualties of personnel can be reduced; the publication number CN109355992A, Chinese application entitled "karst region prevents suddenly and collapses the roadbed structure and construction method" discloses "karst consolidates the foundation surface layer and slots and inlays the reinforced concrete frame structure, the reinforced concrete frame structure is by the longitudinal beam that the horizontal interval sets up and the horizontal beam that the vertical interval sets up, and consolidate as an organic whole in the node where the longitudinal beam, horizontal beam meet, lay the high strength geotechnological material on consolidating the foundation surface, reinforced concrete frame structure top surface, set up the prefabricated pressure beam of the longitudinal extension above each longitudinal beam, the fixed rod that the vertical interval sets up is worn and prefabricated the pressure beam, the high strength geotechnological material is fixedly connected with the longitudinal beam, clamp it on the contact surface of the high strength geotechnological material and prefabricated pressure beam, vertical beam and fix; the Chinese application with the publication number CN 103628461A, namely a karst soil cave region roadbed horizontal stiffening treatment and collapse early warning device, discloses that a reinforced concrete lattice beam and a geogrid are used as a bearing structure of a karst soil cave region roadbed, the thickness of the lattice beam and the section of the lattice beam are designed according to the depth and the density of soil caves, the geogrids are laid on the upper side and the lower side of the reinforced concrete lattice beam, and when the karst soil cave sinks, the reinforced concrete lattice beam and the geogrid can still support the roadbed to prevent vehicles from falling into the cave; the two anti-collapse devices adopt a method that a reinforced concrete structure is used as a rigid body and is combined with a geosynthetic material to span the cavity, the reinforced concrete structure has higher manufacturing cost, if the reinforced concrete structure is used for preventing and treating soil bodies above the cavity with a proved large span, the reinforced concrete structure is valuable and not wasted, and a template needs to be erected during construction, so that the complexity is high and the construction period is long. Therefore, the method for preventing and treating the collapse of the large-span and small-span cavities is economically important, especially when the cavities are not detected or can be developed after work.

Disclosure of Invention

The invention provides a cavity collapse prevention and treatment structure and a construction method, which can prevent and treat the problem of large-span and small-span cavity collapse at the same time, reduce the construction cost and have economical efficiency.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a cavity collapse prevention and control structure is characterized in that the prevention and control structure is erected above an underground cavity collapse area;

the prevention and control structure comprises geotextile laid above an underground cavity collapse area, a reinforced space body is arranged on the geotextile, the geotextile integrally wraps the reinforced space body to form a wrapping structure, and a plurality of pumping pipeline inlets are preset at the top end of the wrapping structure;

the control structure also comprises a protective structure which is arranged above the wrapping structure;

the reinforced space body comprises a geogrid and geocell chambers which are formed by staggered, overlapped and laid from bottom to top;

as a further preferred aspect of the present invention,

the geogrid comprises a plurality of geogrid transverse ribs and a plurality of geogrid longitudinal ribs which are connected in a crisscross mode; the cross joints of the transverse ribs and the longitudinal ribs of the geogrid form cross joints, and reinforcing nodes are arranged on the surfaces of the cross joints or the bottom surfaces of the cross joints or the surfaces and the bottom surfaces of the cross joints;

as a further preferred aspect of the present invention,

the geocell comprises a plurality of wavy geocell strips, wherein the geocell strips are positioned on the same plane, and adjacent geocell strips are connected at a bent part;

as a further preferred aspect of the invention, a plurality of holes are uniformly formed on the geocell bar;

as a further preferable mode of the invention, the protective structure is a balloon, the surface of the balloon is in an arc-shaped structure, the bottom of the balloon is flat, and the balloon is attached to the top of the reinforced spatial body;

as a further preferred aspect of the present invention, a plurality of deformation acquisition alarm systems are installed at the bottom of the geotextile;

a construction method for a cavity collapse prevention structure based on any of the above claims, comprising the steps of:

the first step is as follows: manufacturing geogrids, namely fixedly connecting a plurality of geogrid transverse ribs and a plurality of geogrid longitudinal ribs in a crisscross manner to form the geogrids, and installing reinforcing nodes on the surfaces or the bottoms of cross-shaped intersection points or installing the reinforcing nodes on the surfaces and the bottom surfaces of the intersection points at the same time;

the second step is that: manufacturing a geocell, placing the surfaces of a plurality of wavy geocell strips vertical to the ground, arranging the plurality of geocell strips in parallel, and binding the bending parts of the adjacent geocell strips;

the third step: laying geotextile on the surface of the underground cavity collapse area, overlapping the geotextile in a staggered manner according to the sequence of geogrids and geocells, wherein the geogrids and the geocells are connected by binding, and the overlapped height meets the filling height and design requirements of the embankment;

the fourth step: after the geogrid and the geocell are overlapped in a staggered mode, a reinforced spatial body is formed, geotextile is wrapped around the reinforced spatial body, the top of the reinforced spatial body is sewn to form a wrapping structure, a plurality of pumping pipeline inlets are reserved at the top of the sewn wrapping structure, and a plurality of deformation acquisition alarm systems are installed at the bottom of the geotextile;

the fifth step: filling embankment filler around the reinforced space body until the filler reaches the top elevation of the reinforced space body, starting a pump to convey the flowing solidified waste mud to the reinforced space body, and forming a rigid body similar to the reinforced concrete beam by the solidified waste mud and the reinforced space body;

and a sixth step: placing a balloon at the top of the reinforced spatial body, enabling connecting pipelines on two sides of the balloon to extend out of an embankment side slope, then continuously filling embankment filler at the top of the balloon until the embankment filler reaches a design height, after a local cavity collapse area collapses, enabling the bottom of the geotextile wrapping layer to deform or tear, triggering a deformation acquisition alarm system, injecting liquid or gas into the balloon through a pipeline at the moment, and forming an arch shape on the surface of the balloon.

Through the technical scheme, compared with the prior art, the invention has the following beneficial effects:

1. the reinforced space body and the solidified waste mud form a rigid body similar to a reinforced concrete beam, so that the crossing cavity can effectively prevent the subgrade from collapsing, and meanwhile, subgrade settlement and side slope deformation are reduced;

2. according to the geotextile, the reinforced space body is wrapped to form a prevention structure, so that the deformation of the reinforced space body is limited;

3. the geotextile can effectively prevent the waste mud from falling into the underground cavity;

4. according to the invention, the protective structure, namely the balloon is arranged at the top of the reinforcement space body, and when the whole prevention and treatment structure is deformed and torn, and the deformation acquisition alarm system is triggered, the balloon is subjected to secondary protection, so that the top load can be resisted.

Drawings

The invention is further illustrated with reference to the following figures and examples.

FIG. 1 is a schematic overall structure of a preferred embodiment of the present invention;

FIG. 2 is a side view of a structure of a reinforcement space body according to a preferred embodiment of the present invention;

fig. 3 is a schematic view of a geocell structure according to a preferred embodiment of the present invention;

fig. 4 is a schematic view of a geogrid structure according to a preferred embodiment of the present invention;

FIG. 5 is a schematic view of the preferred embodiment of the invention without the balloon bulging;

fig. 6 is a schematic diagram of the balloon bulge of the preferred embodiment of the present invention.

In the figure: the underground cavity collapse area is 1, the geotextile is 2, the geogrid is 3, the geocell is 4, the pipeline is 5, the balloon is 6, the crack is 7, the embankment filler is 8, the reinforcing node is 9, the geogrid transverse rib is 10, the geogrid longitudinal rib is 11, the geogrid strip is 12, the hole is 13, the deformation acquisition alarm system is 14, the waste mud is 15, and the pumping pipeline inlet is 16.

Detailed Description

The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic views illustrating only the basic structure of the present invention in a schematic manner, and thus show only the constitution related to the present invention.

In the existing technology for arranging the prevention structure in the underground cavity collapse area, a reinforced concrete structure rigid body or a geosynthetic material is adopted as a main body of the prevention structure, but when the span of a horizontal cavity is large, the geosynthetic material is flexible, and the reinforcement body cannot completely prevent and control the deformation of a roadbed caused by the collapse of the cavity; the reinforced concrete structure rigid body crossing method has good effect, but high cost, is valuable for preventing and treating the soil body above the explored large-span cavity, but is not economical, complex in construction and long in construction period for preventing and treating the soil body which is possibly developed into the cavity after construction or the cavity with smaller span.

Based on the defects, the application provides a cavity collapse prevention structure which is erected above an underground cavity collapse area 1; the whole structural characteristics of the control structure can be seen from fig. 1, including the geotextile 2 laid above the underground cavity collapse area 1, the reinforced space body is arranged on the geotextile 2, the reinforced space body is wrapped by the geotextile 2 at the same time, a plurality of pumping pipeline inlets 16 are preset after the top end of the geotextile is sewn, and the protective structure is arranged above the pumping pipeline inlets 16.

In this application, add muscle space body and include geogrid 3, geotechnological check room 4 and lay by crisscross stack from bottom to top and form.