CN-115539077-B - Supporting structure of slag collecting pit of diversion tunnel

CN115539077BCN 115539077 BCN115539077 BCN 115539077BCN-115539077-B

Abstract

The invention discloses a supporting structure of a diversion tunnel slag collecting pit, which comprises an advanced radial grouting layer, a steel mesh layer, an injection concrete layer, a concrete lining and a plurality of radial anchor rods, and further comprises a plurality of anti-seismic connecting units, wherein each anti-seismic connecting unit comprises a central connecting mechanism, a plurality of connecting rods, one ends of the connecting rods are abutted to the surface of the steel mesh layer, the other ends of the connecting rods extend into the injection concrete layer and extend out, one ends of the connecting rods are hinged to the side wall of the same central connecting mechanism, the other ends of the connecting rods are respectively sleeved on free sections of the radial anchor rods, one sides of the tension members are fixed with the parts of the central connecting mechanisms extending out of the injection concrete layer, and the other sides of the tension members are pre-pressed and fixed with a steel reinforcement cage in the concrete lining. The invention has the beneficial effect of improving the vibration effect generated during the blasting resistance in the tunnel excavation process.

Inventors

YE MING
HE JINXING
LI JIANG
DENG LINAN
ZHAI ZHONGBAO
WANG WEIZHI
XIA HUANYUAN

Assignees

中国水利水电第六工程局有限公司

Dates

Publication Date: 20260512
Application Date: 20221025

Claims (5)

1. The utility model provides a support structure of diversion tunnel collection pit, includes radial slip casting layer, steel mesh layer, shotcrete layer, concrete lining and a plurality of radial stock in advance, its characterized in that still includes a plurality of antidetonation connecting elements, and every antidetonation connecting element includes: one end of the central connecting mechanism is abutted against the surface of the steel mesh layer, and the other end of the central connecting mechanism stretches into the sprayed concrete layer and stretches out; One end of each connecting rod is hinged to the side wall of the same central connecting mechanism, and the other end of each connecting rod is sleeved on the free sections of the radial anchor rods respectively; One side of the tension piece is fixed with the part of the central connecting mechanism extending out of the sprayed concrete layer, and the other side of the tension piece is pre-pressed and fixed with a reinforcement cage in the concrete lining; wherein, the center coupling mechanism includes: the outer side wall of the central rod is provided with a plurality of clamping ribs at intervals, and the outer side wall of the central rod is provided with at least one strip-shaped groove; The sleeve joint cylinders are respectively sleeved at two ends of the central rod, a plurality of clamping grooves are formed in the inner side wall of the sleeve joint cylinder at intervals, at least one threaded hole is formed in the side wall of the sleeve joint cylinder along the radial direction, the clamping grooves are clamped outside the clamping ribs, bolts are screwed on the threaded holes, and the lower ends of the bolts extend into the grooves; The center ring is movably sleeved on the center rod and is positioned between the pair of sleeved cylinders; The connecting rod includes: The two ends of the telescopic rod body are respectively provided with a pair of connecting rings, and one connecting ring is hinged on the center ring; The connecting cylinder is in a shape with a small middle part and large two ends, the connecting cylinder is sleeved on the free section of the radial anchor rod, a rotating ring is movably sleeved on the middle part of the connecting cylinder, and the rotating ring is hinged with the other connecting ring; the end part of the sleeve joint cylinder, which is positioned in the reinforcement cage, is provided with at least one pair of lugs, and the surface of each lug is provided with an annular groove; The tension member includes: At least one steel plate, at least one pair of threaded holes are formed in the steel plate, guide cylinders are correspondingly arranged on the surfaces of the steel plates facing the lugs, threaded holes are formed in the guide cylinders, the lugs and the threaded holes are fixedly connected through bolts and nuts, and the steel plate is abutted to one or more steel bars of the steel bar cage; The spring is sleeved in the guide cylinder, and the other end of the spring is abutted in the annular groove.
2. The diversion tunnel slag pit supporting structure according to claim 1, wherein the depth of injection of the advanced radial grouting layer is greater than 2m, the spacing and the row.
3. The support structure of the diversion tunnel slag pit according to claim 1, wherein the length of the radial anchor rod is larger than 1.5m, the spacing and the row spacing are 0.6-0.8 m, and the diameter is 22 mm.
4. The supporting structure of the diversion tunnel slag pit as defined in claim 1, wherein the sprayed concrete layer has a thickness of 12 cm.
5. The supporting structure of the diversion tunnel slag pit according to claim 1, wherein the number of connecting rods on the same central connecting mechanism is 4-6.

Description

Supporting structure of slag collecting pit of diversion tunnel Technical Field The invention relates to the technical field of tunnel excavation. More particularly, the invention relates to a supporting structure of a diversion tunnel slag collecting pit. Background The main project is a diversion tunnel, the total length of the main tunnel is 4390.945m, and the hole diameter D-2.0m is formed. The tunnel is also provided with a maintenance shaft which is 48.7m in height, 5.87m in length and 5.20m in width, an accident gate (2.5 m in width and 2.0m in height) and a trash rack (2.5 m in width and 2.0m in height) which are arranged in the shaft, and the construction branch hole 1 is arranged in the engineering, and is a permanent branch hole of which the length is 465.489 m. The geological condition of the project spans two categories, one lithology is rock scraps, tuff and weak weathering, the rock is soft rock after being changed along two sides of the joint surface, the joint surface of the rock mass is rough, the joint surface is rough, the part of the joint surface is flat, rough or smooth, the rock scraps or the argillaceous is filled, and the rock mass is broken to form a broken structure. The surrounding rock is unstable. Drip underground of the tunnel to a linear shape. The estimated value of the normal water inflow is 518m 3/d, and the surrounding rock type is IV. The other lithology is rock scraps, tuff and weak weathering, the two sides of the joint surface of the rock are provided with alteration belts, the rock is soft rock, the joint surface of the rock body is in a relief smooth shape, the joint surface is slightly expanded to be opened, the part of the joint surface reaches 10cm, the rock scraps or the argillaceous is filled, and the rock is crushed to be crushed to form a fragment structure to a fragmentation structure. The surrounding rock is extremely unstable. The underground water of the cavern is in a linear flow shape to a water-gushing shape. The maximum water inflow estimated value is 1136m 3/d, and the surrounding rock type is V. The range of saturated compressive strength values of the weakly weathered rock of the two rock scraps tuff types is 31.2-84MPa, and the rock scraps tuff type weakly weathered rock is soft rock, has uneven rock quality and has the characteristic of obvious difference. In the tunnel excavation process, a blasting technology is also required, and a vibration effect generated during blasting can have further adverse effect on the slag pit lining structure. The conventional support forms comprise a hanging net, spraying and mixing, an anchor rod, a concrete lining and the like, and in order to improve the anti-seismic performance, the conventional technology is to thicken the lining structure, but the reinforced concrete engineering quantity is increased, and meanwhile, the transverse excavation span of a slag collecting pit is increased, so that the construction difficulty of excavation of a cavity is increased. Disclosure of Invention It is an object of the present invention to solve at least the above problems and to provide at least the advantages to be described later. To achieve these objects and other advantages and in accordance with the purpose of the invention, there is provided a supporting structure of a diversion tunnel slag pit including a leading radial grouting layer, a steel mesh layer, a shotcrete layer, a concrete lining, and a plurality of radial anchors, and further including a plurality of anti-seismic connection units, each anti-seismic connection unit including: one end of the central connecting mechanism is abutted against the surface of the steel mesh layer, and the other end of the central connecting mechanism stretches into the sprayed concrete layer and stretches out; One end of each connecting rod is hinged to the side wall of the same central connecting mechanism, and the other end of each connecting rod is sleeved on the free sections of the radial anchor rods respectively; And one side of the tension piece is fixed with the part of the central connecting mechanism extending out of the sprayed concrete layer, and the other side of the tension piece is pre-pressed and fixed with a reinforcement cage in the concrete lining. Preferably, the center connection mechanism includes: the outer side wall of the central rod is provided with a plurality of clamping ribs at intervals, and the outer side wall of the central rod is provided with at least one strip-shaped groove; The sleeve joint cylinders are respectively sleeved at two ends of the central rod, a plurality of clamping grooves are formed in the inner side wall of the sleeve joint cylinder at intervals, at least one threaded hole is formed in the side wall of the sleeve joint cylinder along the radial direction, the clamping grooves are clamped outside the clamping ribs, bolts are screwed on the threaded holes, and the lower ends of the bolts extend into the grooves; The center r