CN-117607407-B - Sprayed concrete slurry hanging testing device for tunnel rock burst flexible net

CN117607407BCN 117607407 BCN117607407 BCN 117607407BCN-117607407-B

Abstract

The invention discloses a shotcrete hanging test device for a tunnel rock burst flexible net, which comprises a device frame, a lateral retaining structure, a flexible protective net, a concrete automatic spraying mechanism and a shotcrete collecting tank, wherein the top of the device frame is used for supporting a top cambered steel plate, a layer of cambered concrete layer is sprayed on the bottom cambered surface of the top cambered steel plate, the lateral retaining structure is used for retaining the front side, the back side, the left side and the right side of the device frame and preventing the shotcrete from being accidentally sprayed out of a test device, the flexible protective net is paved on the lower surface of the cambered concrete layer, the concrete automatic spraying mechanism is arranged at the bottom of the device frame and used for spraying concrete again on the flexible protective net coverage, and the shotcrete collecting tank is used for collecting concrete with hanging failure.

Inventors

WANG MEIXIA
BAI YIFAN
YANG WEIMIN
HAN GUANGDONG
SHI SHAOSHUAI
SONG XUAN
LIU LANG
MA SHIJIE

Assignees

山东大学
浩珂科技有限公司

Dates

Publication Date: 20260508
Application Date: 20231129

Claims (6)

1. A sprayed concrete slurry hanging testing device for a tunnel rock burst flexible net is characterized by comprising a device frame, a lateral retaining structure, a flexible protective net, an automatic concrete spraying mechanism and a sprayed concrete collecting groove, wherein the top of the device frame is used for supporting a top cambered steel plate, a layer of cambered concrete layer is sprayed on the bottom cambered surface of the top cambered steel plate, the lateral retaining structure is used for retaining the front side, the back side, the left side and the right side of the device frame and preventing the sprayed concrete from being accidentally sprayed out of the testing device, the flexible protective net is paved on the lower surface of the cambered concrete layer, the automatic concrete spraying mechanism is arranged at the bottom of the device frame and used for covering the sprayed concrete on the flexible protective net, and the sprayed concrete collecting groove is arranged at the bottom of the automatic concrete spraying mechanism and used for collecting concrete failed in slurry hanging.
2. The device for testing the grouting concrete of the tunnel rock burst flexible net, as set forth in claim 1, wherein the device frame is a bearing structure welded by a plurality of rectangular steels, and comprises four bearing columns, four bearing beams respectively connected with the tops of the four bearing columns, and four bearing beams at the bottoms of the four bearing beams, wherein four oblique beams are welded at four corners of the bottoms of the four bearing beams at the tops, the bottoms of the four oblique beams are connected with the top cambered steel plate, and two sides of the bottom of the top cambered steel plate are also supported on the two bearing beams at the bottom of the bearing structure through two support columns.
3. The device for testing the slurry hanging of the sprayed concrete for the tunnel rock burst flexible network of claim 2, wherein the lateral retaining structure comprises a left side baffle and a right side baffle which are respectively arranged on the left side and the right side of the bearing structure, and further comprises a front baffle and a rear baffle which are respectively arranged on the front side and the rear side of the bearing structure and can be transversely pulled away or closed from the middle part, wherein the front side and the rear side of the bearing structure are respectively provided with two front baffles and rear baffles, the front side of the front baffle is respectively in sliding connection with baffle sliding grooves arranged on the front side of the left side baffle and the front side of the right side baffle, and the rear side of the front baffle and the rear baffle are respectively in sliding connection with baffle sliding grooves arranged on the rear side of the left side baffle and the right side baffle.
4. The device for testing the grouting of the sprayed concrete of the tunnel rock burst flexible network according to claim 1, wherein the flexible protective network is paved on the lower surface of the cambered surface concrete layer through threaded anchor rods and anchoring components, square gaskets are adopted at the position of each threaded anchor rod to fix the flexible protective network, meshes of the flexible protective network penetrate through the threaded anchor rods firstly, then the gaskets penetrate through the threaded anchor rods, and finally anchor rod matched nuts are tightened, so that the flexible protective network and the gaskets are tightly attached to the lower surface of the cambered surface concrete layer.
5. The device for testing the grouting concrete of the tunnel rock burst flexible net according to claim 2, wherein the automatic concrete injection mechanism comprises a sliding rail, a sliding table and a concrete injection head, the concrete injection head is rotatably connected to the top of the sliding table and driven by a motor to swing left and right, the sliding table is slidably connected to the sliding rail, a linear motor is driven to move back and forth along the sliding rail, and the front side and the rear side of the sliding rail are fixed on two bearing beams on the front side and the rear side of the bottom of the bearing structure.
6. The device for testing the shotcrete hanging slurry for the tunnel rock burst flexible net according to claim 2, wherein the shotcrete collecting tank is arranged below the bearing beam at the bottom of the bearing structure, and the shotcrete collecting tank is movably arranged and can be placed in or pulled out from the bottom of the bearing structure.

Description

Sprayed concrete slurry hanging testing device for tunnel rock burst flexible net Technical Field The invention relates to the technical field of tunnel construction, in particular to a sprayed concrete slurry hanging testing device for a tunnel rock burst flexible net. Background In the construction process of railway tunnels, tunnel excavation stability can be affected by complex geological environments. Under the high ground stress condition, the phenomenon of dynamic instability, namely rock burst, induced by brittle hard rock after excavation unloading seriously affects the safe construction of tunnel excavation, and has great potential safety hazards of life and property. In order to ensure the stability of tunnel excavation, after the underground cavity is excavated, surrounding rock support is used as the most direct and effective rock burst prevention measure, so that more and more researches are carried out, and most of the researches are based on an anchor rod-protective net-shotcrete (anchor net spraying for short) support system, so that the rock burst prevention performance of the support system is continuously improved. The flexible protective net is used as an emerging polymer material, is made of polymeric filament fibers and an advanced coating technology, has the characteristics of high strength and high toughness, plays roles of flexible buffering and flexible energy release in rock burst protection, and is very beneficial to the protection of tunnel rock burst disasters. Although the flexible protective net has the advantages, the cooperative construction process of the material and other supporting structures in the tunnel needs to be further explored so as to achieve the purposes of safety, high efficiency and economy. In the tunnel construction process, the flexible protection network of stock fixed part is fine with the laminating of rock face, however, the characteristics of hardness are low lead to keeping away from the net material of stock department and hang down naturally because of the action of gravity easily, this can cause follow-up shotcrete to be difficult to the slurry coating on the net material to cause shotcrete to drop on a large scale, seriously extravagant raw materials and can lengthen man-hour. This phenomenon is not present in the conventional metal protection network. In summary, it is necessary to develop a device to perform experimental analysis on the laying mode of the flexible protection net in the tunnel, and perform experimental comparison on the laying effects of the net materials with different materials and sizes, so as to obtain the laying mode and the net material parameters which are most beneficial to tunnel construction. Disclosure of Invention The invention aims to provide a shotcrete grouting testing device for a tunnel rock burst flexible net, which is used for solving the problems existing in the prior art. In order to achieve the above object, the present invention provides the following solutions: The invention provides a shotcrete slurry hanging testing device for a tunnel rock burst flexible net, which comprises a device frame, a lateral retaining structure, a flexible protective net, a concrete automatic spraying mechanism and a shotcrete collecting tank, wherein the lateral retaining structure is arranged on the device frame; The top of the device frame is used for supporting a top cambered surface steel plate, and a cambered surface concrete layer is sprayed on the bottom cambered surface of the top cambered surface steel plate; The lateral supporting structure is used for blocking the front side, the back side, the left side and the right side of the device frame and preventing the re-spraying concrete from being accidentally sprayed to the range outside the test device; the flexible protective net is paved on the lower surface of the cambered surface concrete layer; the automatic concrete spraying mechanism is arranged at the bottom of the device frame and is used for spraying concrete again on the coverage area of the flexible protective net; The sprayed concrete collecting tank is arranged at the bottom of the automatic concrete spraying mechanism and is used for collecting concrete with failed hanging paddles. Preferably, the device frame is a bearing structure obtained by welding a plurality of rectangular steels, and comprises four bearing columns, four bearing beams respectively connected with the tops of the four bearing columns, and four bearing beams at the bottoms of the four bearing beams, wherein four oblique beams are welded at four corners of the bottoms of the four bearing beams at the tops, the bottoms of the four oblique beams are connected with the top cambered surface steel plate, and two sides of the bottom of the top cambered surface steel plate are supported on the two bearing beams at the bottom of the bearing structure through two support columns. Preferably, the lateral retaining structure comprises a left s