Construction method for dam body seepage preventing curtain grouting

Abstract

The invention relates to a construction method for dam body seepage preventing curtain grouting and provides a construction method for the dam body seepage preventing curtain grouting. The grouting is carried out by a technology of dense holes, high pressure, fine cement wet grinding and concentrated slurry, and the seepage preventing ability, the corrosion resistance and the durability of a dam body curtain are improved; the seepage is prevented in a way of front blockage and rear discharge, the downstream seepage escapement point elevation of a dam body and the uplifting pressure in a dam are reduced, and the problems of frozen thawing and frozen expansion of concrete are solved. The construction method for the dam body seepage preventing curtain grouting comprises the following steps of: a. downwards drilling a group of curtain grouting holes at the top of the dam; b. drilling radial grouting holes on the upstream surface in a basic gallery; c. downwards drilling curtain connection grouting holes extending into a dam foundation in the basic gallery; d. carrying out grouting by high pressure, fine cement wet grinding and concentrated slurry; and e. drilling a water discharge structure which is communicated with the basic gallery in the dam body. The invention is mainly used for the seepage prevention and discharge reinforcement processing of the concrete dam.

Description

technical field [0001] The invention relates to a construction method for grouting an anti-seepage curtain of a dam body. It is mainly suitable for the anti-seepage and drainage reinforcement treatment of concrete dams. In addition, it can also be used as a reference for the anti-seepage treatment of other local material dams. Background technique [0002] The anti-seepage and drainage treatment of existing dams is very difficult. In the past, two methods of anti-seepage on the upstream surface of the dam and anti-seepage inside the dam body were often used. Among them, concrete, geomembrane, and special anti-seepage chemical materials are usually used for anti-seepage on the upstream surface of the dam, and most of them require underwater construction, which is difficult, long-term, and unsatisfactory. If the water level of the reservoir is emptied or lowered, it will have a great impact on the surrounding environment, upstream and downstream industrial and agricultural pr...

AI Technical Summary

Problems solved by technology

Anti-seepage curtain grouting is a conventional and mature construction technology with a complete set of theories and relatively simple construction. It is widely used in dam foundation and dam body anti-seepage and reinforcement projects, but the existing dam body The anti-seepage curtain grouting has the following disadvantages: 1. The technology is backward. Usually, the dam foundation curtain grouting method is applied, and the "porosity, low pressure, ordinary cement, thin slurry" process is used. This method is difficult to form an effective curtain with a certain thickness. The impermeability , corrosion resistance, and poor durability; 2. The drainage system is not perfect. The existing dam body drainage generally adopts the vertical downward drainage method, and vertical drainage holes are directly drilled on the top of the dam to connect with the foundation corridor in the dam. The curtain body produces a large hydraulic shaving; 3. The anti-corrosion measures of the curtain body are not paid attention to, so that the durability of the curtain body is poor, and the phenomenon of short-term repeated grouting is relatively common

Cement hydration needs less water, but the prepared cement slurry is relatively thin. If the slurry poured into the gap does not take measures to remove excess water, pores will remain after the slurry solidifies, resulting in lower stone strength.

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