用户名: 密码: 验证码:
田湾河流域仁宗海水库电站坝基防渗墙施工技术
详细信息    本馆镜像全文|  推荐本文 |  |   获取CNKI官网全文
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。
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 .
引文
[1] 高钟璞等.大坝基础防渗墙.中国电力出版社,2000.2
    [2] 成勘院.四川省田湾河仁宗海水库电站可行性研究报告,2003.
    [3] 水利水电工程混凝土防渗墙施工技术规范(SL 174-96).
    [4] S. M. Voskresenskii and L. I. Malyshev. Current Special Hydrotechnical Construction Works. Power Technology and Engineering, October 2000, Volume 34, Number 10:517-519.
    [5] 叶书麟编.地基处理.中国建筑工业出版社,1988.8.
    [6] 刘金励主编 桩基工程技术.中国建筑工业出版社,1996.8.
    [7] Sowa, V. A., R. M. Hardy, and B.D. Constant. Design and construction of a dam on soft foundations. 31st Canadian Geotechnical Conference, 1978.
    [8] Burke, H.H., and S.S. Smucha. Lomex tailings dam on a soft foundation. Proceedings of the Sixth Pan-American Conference on soil mechanics and foundation engineering. 1979.
    [9] 曾国熙,王铁儒.顾尧章.砂井地基的若干问题.岩土工程学报,1981.
    [10] 郎小燕,来妙法,金小玲.振冲法对多层软弱坝基的处理.浙江水利科技,1998.
    [11] Davis, J. &C., Humpheson. 1981. A comparison between the performance of two types of vertical drains beneath a trial embankment in Belfast. Geotechnique 31, No. 1:17-29.
    [12] Chin, B.G., D.M., Davis, E.J. Koohn, R.P., Benson, and Campell, J.W. 1991. Construction performance of the Forty Mile Coulee east dam on a soft clay foundation. Canadian Geotechnical Conference. Pt2, Sep. 29-Oct. 2, 1:1-9.
    [13] Countinho, R.Q., M.S.S., Almeida, and J. B., Borges. 1994. Analysis of Juturnaiba embankment dam built on an organic soft clay. Geotechnical Special Publication. Vol. 1, Jun. 16-18, No. 40:348-363.
    [14] Holubec, I., J., Dobson, and S. Manson. Design and construction of an erath dam on highly plastic clay using wick drain foundation. Canadian Geotechnical Conference Sep1993, 27-29.
    [15] 陈祖煜,周晓光,陈立宏等.云南务坪水库软基筑坝技术.中国水利水电出版社:中国水利水电科学研究院岩土工程研究所,2004.12.
    [16] 建筑物地基处理技术规范(JG79-91)[S].
    [17] 建筑物桩基技术规范(JG94-94)[S].
    [18] 地基处理技术[M].中国环境科学出版社,1996.
    [19] 软土地基加固[M].上海科学技术出版社,1990.
    [20] 赵淑昱,邹娅.软弱粘土地基处理方案的分析,2002.
    [21] 四川省田湾河流域仁宗海水库电站坝基防渗墙施工问题咨询意见,2005.10.
    [22] 郎小燕,来妙法,金小玲.振冲法对多层软弱坝基的处理[J].浙江水利科技,1998.
    [23] 水电水利规划设计总院.四川省田湾河仁宗海水库水电站可行性研究报告审查意见,2003.
    [24] 成勘院.四川省田湾河仁宗海水库电站堆石坝基淤泥质壤土振冲碎石桩施工技术要求,2005.
    [25] 成勘院物探中心.四川省田湾河仁宗海水库电站坝基防渗墙是施工检测报告,2006.
    [26] 水利水电施工工程师手册.中科多媒体电子出版社,2003.

© 2004-2018 中国地质图书馆版权所有 京ICP备05064691号 京公网安备11010802017129号

地址:北京市海淀区学院路29号 邮编:100083

电话:办公室:(+86 10)66554848;文献借阅、咨询服务、科技查新:66554700