田湾河流域仁宗海水库电站坝基防渗墙施工技术

【作者】 张邦全；

【导师】 何江达； 唐剑虹；

【作者基本信息】 四川大学 ， 水利工程， 2006， 硕士

【摘要】 随着我国国民经济持续稳定的高速发展对电力需求的不断增加，近十年来，以开发水能资源来满足各行业经济发展而兴建的水电工程越来越多，不仅需要选择在地基条件良好的场地从事建设，而且有时也不得不在地质条件不良的地基上进行修建。同时，随着水电工程规模的不断加大结构物的荷载日益增大，对地基变形与防渗要求越来越严，地基已成为制约工程建设的主要因素，因此，地基处理的重要地位也日益明显。在追求经济效率时，如何选择一种既满足工程要求，又兼顾好生态环境和节约投资的处理方法，已经刻不容缓的呈现在广大的工程建设者面前。河床中的深厚覆盖层，由于具有低强度，高压缩性和弱透水性，作为坝基，常常成为棘手的工程地质问题。在这种地基上建造工程。必须进行地基处理。地基处理的目的就是采取适当的工程措施改善地基条件，使之满足变形、强度和防渗要求，主要包括：改善剪切特性、压缩特性、透水特性、动力特性、特殊土的不良地基特性等。仁宗海水库电站堆石坝坝址区地质条件十分复杂，坝基有深厚覆盖层，从上自下共分七层。完全在软弱的淤泥质壤土层地基上修建大坝，在国内外还没有先例。经过方案比较，仁宗海水库电站坝基淤泥质壤土采用振冲碎石桩法进行处理，达到了提高地基承载力、减小大坝地基沉降量、提高坝体及地基的稳定性、消除地基液化的目的；同时，为减小坝体渗透压力，降低渗透系数，减少坝体渗透量，在坝体上游坡脚处设置了一道防渗墙。该防渗墙工程地处高海拔地区，地层复杂，钻孔进尺大，工程量大，施工难度大，施工条件艰苦(冬季最低气温零下14℃以下)。按照规定的工期要求，保质、保量地完成该工程项目，为高海拔、冬季气温低的防渗墙施工提供了宝贵的经验。本文针对田湾河仁宗海坝基处于深厚覆盖层这一地基特点，针对防渗墙施工技术问题引起的工程地质条件复核、造孔设备选用、造孔工艺选择、造孔施工、泥浆下混凝土浇筑、特殊情况处理、质量控制与检测等全过程进行了系统设计和研究，并通过防渗墙现场实施效果，充分证明了田湾河仁宗海水库电站的坝基防渗墙处理是符合客观实际的最好施工方法，也是水工建筑物软基防渗处理的又一成功典范。工程中造孔工艺选择和工程地质条件复核、墙体质量控制与监测为全面评价防渗墙施工效果提供了翔实的资料，丰富了防渗墙施工技术，也为类似工程提供了有益的借鉴。更多还原

【Abstract】 Along with the national economy in a high speed development continuously , the demanding to electric power increases, the hydro-power construction engineerings that explore hydro- resources to satisfy economy development are more and more in the decade come. They are engaged in construction not only at the good foundation condition, and sometimes also at the bad geology condition foundation. Moreover, the loading of constructions enlarge increasingly by dimensions aggrandizes of hydro-power projects, the request to the transforming and the anti-sweeping of the foundation are more and more strict. the foundation has become the main factor that influence construction engineerings, therefore, the importance of foundation processing is also increasingly obvious. While we pursue economic efficiency, how to choose a kind of processing method that satisfy the engineerings request, care about entirement in the meantime, and then economize of the investment, is a very important problem that have already presented in front of engineering constructor urgently.because of having low strength, high compressibility and weak penetration ,the deep overlay in the river bed, be the dam foundation , usually becoming a tough engineering geology problem. It is necessary to carry on a foundation processing if we want to construct engineerings on this kind of foundation. The purpose of the foundation processing is to adopt some appropriate engineering measures to improve the foundation conditions,to satisfy the demand of deform,strength,and antipenetrate mainly include: The measures to improve shears to slice, compression, penetration, motivation and bad foundation of some special soil.The geology condition of the RenzhongHai stone dam is very complicated,there have very deep layer of overlay, from the top to the bottom there are seven layers.In our country and abroad ,none have precedent that buiding a dam on the foundation of weak silt quality soil layer.By contrast,the method of the foundation disposing is flaping and crushing . Through the method,the carring capacity of the foundation have been enhanceed ,the sinking of the foundation have been declined and the stability of the dam and the foundation have been improved ,besides the liquefactio of the foundation have been avoided . In the meantime,in order to declining the permeate pressure,reducing the permeate coefficient and decreasing permeate quantity,the engineering have built a permeating defending wall at the feet of the upriver of the dam.This project is at the high elevation region, the stratum is very complicated ,so the construction condition is very laborious (the lowest air temperature is below zero 14 the°C in the winter) This project provide precious experience for the construction of permeating defending wall at the high elevation region with cold weather.Aiming at the characteristic that the foundation of RenZong hydro-power station is placed in deep overlay, the paper designes and researches systemicilly the whole processes of rechecking engineering geology conditions, choosing the bore equipments and techniques, boring, sprinkling concrete in the mud, processing special circumstance, controlling and examining the quality. and Based on the effects of the anti-penetrate wall,it is well proved that the anti-penetrate wall in the foundation of the station is match of best measure,and is also a successful model of anti-penetrating in soft foundation.It provides thoroughly data for the overall evaluation the building of anti-penetrate wall, enriches the technique of building the wall and provides some use of reference to similar projects .更多还原