Construction method of buried grit chamber

Abstract

The invention provides a construction method of a buried grit chamber. The construction method comprises the following steps of: dividing a dome chamber of the grit chamber into a left half chamber and a right half chamber with the same specification; firstly, excavating the half chamber on the near-slope side, arranging a middle partition wall and a steel support, then excavating the half chamberon the near-water side, and making the steel support; then removing the middle partition wall to complete the excavation of a dome; then excavating an upper chamber of the grit chamber, and carryingout concrete lining and anchor rod support; and finally, excavating a lower chamber of the grit chamber, arranging system anchor rods, carrying out spot welding and binding on the exposed anchor rodsand steel bars, and pouring slope protection concrete. According to the construction method, the ratio of the span to the arch height is reduced, the stress state of the chamber excavation stage is improved, the reliability of the construction safety of the dome chamber is improved, the dome and the upper chamber of the grit chamber adopt the steel support, a steel bar shed frame and hanging net sprayed concrete to form a supporting structure with alternate beam plates, the rigidity of a spraying protection structure is enhanced, good flexibility is achieved, and the economic benefits of the supporting technology in a flat chamber with the shallow buried depth are obvious.

Description

technical field [0001] The invention relates to a construction technology of a grit chamber, in particular to a construction method of a buried grit chamber. Background technique [0002] For the grit chambers arranged in the protruding mountain body of the basin on the side of the river, the buried depth near the slope is usually 30m-40m, and the thickness of the top covering layer is 10m-15m. The strata in the chamber of the grit chamber are mostly strongly weathered gneiss, and the surrounding rocks are classified as IV-V. After the surrounding rocks are exposed, water erosion and argillaceation are easily caused by the influence of water seepage and air. From top to bottom, the grit chamber is divided into a dome, an upper chamber with a straight wall, and a lower chamber with an inverted trapezoidal shape. The rock in the grit chamber is gneiss, and the gneiss is prone to full weathering and strong weathering due to water erosion. , The safety control of cavity forming...

AI Technical Summary

Problems solved by technology

[0004] After the dome of the grit chamber and the upper chamber are excavated, the upper load will cause a large stress concentration phenomenon at the junction of the vertical wall of the upper chamber of the grit chamber and the inverted trapezoidal slope of the lower chamber. If the coefficient is small, when the lower room of the grit chamber is excavated, the stress generated by the load on the side wall of the upper part of the dome of the grit chamber may cause the vertical wall of the upper room and the side wall of the dome to slide and cause the dome to collapse.

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