58results about How to "Surrounding rock stability" patented technology

The invention discloses a supporting system of a water-rich drifting sand stratum full-weathering surrounding rock tunnel and a construction method. At least four layers of steps are arranged in a tunnel. Steel row frame supports are arranged between the steps and the top of the tunnel. An advanced small guide pipe and an advanced pipe shed are arranged at the top of the tunnel. A group of steel arch frames are arranged in the tunnel and are arranged at intervals in the longitudinal direction. The shapes of the steel arch frames are matched with the shape of the section of the tunnel. Pipe shed lock feet are arranged on the two sides of each layer of steps and on the steel arch frames respectively. Steel bar mesh pieces are laid and hung on the portions, between adjacent steel arch frames,of the inner lateral side of the tunnel. Concrete layers fully sprayed on the outer sides of the steel arch frames and the steel bar mesh pieces. Bar-shaped foundations are arranged on the positions,corresponding to the steel row frame supports, of the horizontal planes of the steps. Inclined supports are arranged between the steel row frame supports and the steel arch frames. The supporting system of the water-rich drifting sand stratum full-weathering surrounding rock tunnel and the construction method solve the technical problems that a traditional construction method easily causes settlement of an integral initial support structure, the construction space is small, steel frame arch foot pipe shed locking feet cannot be reinforced, the risk of median septum dismantling is large, the working procedures are complex and the construction speed is low.

The invention discloses a waterproof and drainage system and a construction method of a low-medium radioactive waste grotto type disposal site. The waterproof and drainage system comprises a seepage-preventing side wall and base plate and a waterproof ceiling, wherein the seepage-preventing side wall and base plate is located in a grotto and is U-shaped, the waterproof ceiling is in an inverted-U shape, the waterproof ceiling and the seepage-preventing side wall and base plate are in a buckled-closed state, a clay side wall and base plate is arranged on the inner side of the seepage-preventing side wall and base plate, waste buckets are arranged inside the clay side wall and base plate, an open water draining drain is formed in the outside of the seepage-preventing side wall and base plate and located below the end of the waterproof ceiling, a crane beam is arranged at the top of the seepage-preventing side wall and base plate and located inside the waterproof ceiling, a crane, a grouting pipeline and a spray nozzle are arranged on the crane beam, and a top arched embedded pipeline is arranged in a grotto top arch. The problem that a grotto protection structure existing in an existing project measure is simple and can only retard and reduce the release speed and amplitude of pollutants from a protective facility is well solved, and a series of problems including personal radiation injury and the like due to the grouting and vibrating construction in gaps among the waste buckets are solved.

The invention provides a pre-stress anchor cable structure applicable to an underground powerhouse rock wall crane beam portion. Anchoring segments of the structure are divided into the inner anchoring segment and the outer anchoring segment; the inner anchoring segment is located on the inner side in a drill hole, and the outer anchoring segment is located on the outer side in the drill hole; a tensioning segment is located between the inner anchoring segment and the outer anchoring segment; and in the drill hole, a hole segment corresponding to the tensioning segment and a hole segment corresponding to the outer anchoring segment are partitioned through a slurry stopping bag, and cement slurry is poured in different stages. The pre-stress anchor cable structure applicable to the underground powerhouse rock wall crane beam portion can perform pre-stress anchor cable supporting of a system on a high-edge wall in time, and therefore surrounding rock deformation can be limited, stabilityand safety of a rock wall crane beam structure are guaranteed, and overall surrounding rock stability of an underground powerhouse is facilitated.

The invention provides a construction method for drainage of a tunnel vault in a karst area, and belongs to a construction method of a tunnel. The construction method is characterized in that in tunnel construction, firstly, straight holes are drilled in a rock stratum of the excavated tunnel vault, guiding pipes are driven in the straight holes, the guiding pipes are arranged in a quincunx shape,grouting is conducted between every two adjacent guiding pipes at intervals or grouting is not conducted between every two adjacent guiding pipes, the grouted guiding pipes have the function of stabilizing surrounding rock, the non-grouted guiding pipes have the function of late draining water in the surrounding rock, after the surrounding rock is fixed, the tunnel continues to be excavated; after the guiding pipes are driven into the vault of the tunnel wall, grooves in right-angle n shapes are dug in the position, corresponding to the parts located on the left side and the right side of thecenter line of a circular-arc-shaped vault of the tunnel by 15 degrees, of the tunnel wall with sprayed concrete layers, cuboid steel plates with evenly-distributed circular holes are correspondinglyembedded in the grooves, the steel plates are pitched into the rock stratum of the vault, thus part of water amount of a karst water system can be released, later stress concentration caused by a large amount of water is effectively avoided, and the serious quality and safety problems of the tunnel are avoided.

The invention provides a tunnel-before-wall-type crossed tunnel portal excavation supporting construction method. A tunnel is excavated before cavern side walls, after system supporting is completed,the tunnel extends into a cavern, temporary supporting is conducted to ensure site construction safety, locked anchor bars and countersunk anchor bars are implemented to protect intersections, pre-splitting holes are formed in the circumferential direction along the cavern side walls for blasting, rock mass, nearby the intersections, inside and outside the cavern side walls is separated, during later excavation of the cavern, the rock mass within the pre-splitting range is mechanically excavated, secondary blasting damage is avoided, and system supporting follows till the intersections are excavated. A scheme for solving the problem of excavation supporting of the large underground cavern intersections is provided for a tunnel-before-wall-type excavation mode, excavation forming of the intersections can be ensured to a great extent, stability of surrounding rock of the tunnel intersections and the cavern high side walls is facilitated, overexcavation is reduced, later backfilling of alarge amount of concrete is avoided, the construction period is shortened, and the engineering cost is saved.

The invention relates to a novel large-span tunnel excavating construction method, namely, an excavating method for jump-digging of a double-side wall guide pit combined arch part. After the construction of a double-side wall guide pit and side wall secondary lining is completed, a large-span tunnel arch soil body is excavated by blocks. During the excavation of the arch part of the tunnel, a middle guide pit of the arch part is excavated first, then two side guide pits of the arch part of the tunnel are excavated from the excavation surface of the middle guide pit to the two sides by departing from an opening, a primary supporting structure and the secondary lining of the arch part at the position are constructed, and then the excavation of a arch part structure of the tunnel with large span is completed gradually from inside to outside. The method considers the space effect of tunnel excavation and support, reduces stress concentration at the opening during the excavation of the arch part, and has remarkable effects in ensuring the stability of excavating surrounding rocks at the section of the tunnel with large span and controlling the settlement of a larger area caused by the tunnel excavation.

The invention relates to an excavation method of a large-diameter cylindrical tailrace surge chamber and belongs to the technical field of water conservancy and hydropower underground engineering construction. The excavation method adopts the technical scheme that firstly, middle drift penetrating and reserved protection layer stage excavation are performed, partitioning penetrating is conducted from inside to outside, and thin-layer excavation and layer-by-layer supporting are adopted; stage adjustment and releasing of surrounding rock stress are achieved, and stress drastic adjustment aftersurrounding rock excavation decompression caused by deep-hole-bench large-charge blasting is avoided; fork segment tailwater pipes adopt pre-stressed anchor cable reinforced supporting and first-stageside wall and vault concrete pouring which are are combined, and the two adjacent tailwater pipes adopt the comprehensive excavation construction scheme of drift vertical excavation and layer-by-layer supporting, and the carrying capacity of a bottom fork reserved rock partition wall is remarkably improved. Since the two adjacent tailwater pipes adopt the comprehensive excavation construction scheme of drift vertical excavation and layer-by-layer supporting, the problems that the surrounding rock stress state after practical engineering construction excavation is implemented is complex, driftintersection positions have stress concentration and large plastic zones, and the construction technical difficulty is high are solved.

The invention provides a blasting method for a shallow-buried goaf of a strip mine and belongs to the technical field of engineering blasting. The blasting method comprises the following steps that step1, properties, occurrence conditions and geometric spatial characteristics of ores around the goaf are confirmed; step2, the safety thickness of a top plate above the goaf is confirmed, perforating equipment is selected, and a perforating scheme is designed; step3, hole net parameters of goaf top plate loose blasting and lateral throwing blasting are confirmed, and a charging structure and a detonating network are designed; step4, the muck pile size is estimated; step5, goaf volume balance calculation is performed, and the blasting collapse volume is confirmed; step6, blast hole arranging, charging and filling are performed; and step7, the detonating network is connected, detonating is performed, and the caving filling effect is observed and recorded. According to the blasting method for the shallow-buried goaf of the strip mine, the lateral free surface condition created by the underground goaf is fully utilized, lateral throwing filling is assisted while top plate caving filling is implemented, single-side, double-side or multi-side lateral blasting throwing filling can be implemented, the filling rate of the underground goaf is increased, and secondary manual filling is reduced or avoided.

The invention discloses a tunnel construction method for crossing the earth-rock boundary layer, which comprises the following steps: 1. Excavation of the rear tunnel section and initial support construction; 2. Excavation of the middle tunnel section and initial support construction; 3. Front side The excavation and initial support construction of the tunnel section; the rear tunnel section, the middle tunnel section and the front tunnel section are all three-step synchronous excavation tunnel sections; during the excavation process from the back to the front, the construction is formed from the back to the front Construction of the secondary lining of the tunnel is carried out on the inner side of the primary support structure of the tunnel. The invention is reasonable in design, easy in construction and good in use effect. According to the positional relationship between the soil-rock interface and the tunnel hole, a suitable drilling and blasting method is selected, and three-step synchronous excavation is used for blasting excavation, which can ensure the tunnel's tunnel crossing the soil-rock boundary. The excavation process is safe and reliable, and can ensure the stability of the tunnel structure; and during the excavation process, the tunnel primary support structure and the secondary lining of the tunnel are used to provide stable and reliable support for the large-section tunnel.