针对城市深埋隧洞超深超大竖井支护型式选型、结构尺寸合理拟定、控制竖井变形等设计重难点问题,以深圳LT输水隧洞工程3#工作井为例,详细阐述了超深超大竖井支护选型、稳定计算和结构设计全过程.193个深基坑工程案例表明,对于深度大于40m的基坑,支护型式普遍采用地下连续墙,墙体厚度普遍取为I.2m.理论计算结果揭示:3#工作井支护采用1.2m厚的地下连续墙,12种工况墙体倾覆稳定系数为1.30～3.21,墙内侧水平位移最大值为9.89mm,稳定和变形满足规范要求,1.2m厚地下连续墙支护设计方案可行.调研的大量工程案例及采用的理论计算方法将为其他城市深埋隧洞竖井设计提供可靠的借鉴经验.

针对岩溶帷幕灌浆效果评价存在控制因素多、难以统筹定量分析、现行方法具有片面性等问题,提出了基于模糊综合评价法的灌浆效果评价模型.首先构建了模型因素集U、评价集V、评价矩阵R,然后确定了基于层次分析法的权系数向量D,通过模糊合成算子得到了决策集E,实现了灌浆效果多维度定量评价.并以构皮滩水电站为例对模型进行了验证分析,分析结果表明:提出的灌浆效果评价模型与现行传统评价方法具有较好的同步性,但相较于现行方法,该模型不仅可反馈灌后岩体透水率,也可诠释灌后岩体完整性和岩溶封堵程度,具有更高的评价维度和更全面真实的评价体系,具有广阔的行业推广前景.

深厚覆盖层上200 m级高土石坝的坝体心墙与坝基防渗墙的连接至关重要.随着深厚覆盖层上高坝建设的发展,防渗墙与黏土(砾石土)心墙采用廊道进行连接的情况越来越多.根据工程实践中暴露出的问题,对廊道与防渗墙布置、廊道与防渗墙之间的连接、廊道分缝、廊道和防渗墙与心墙连接部位防渗抗渗等构造设计问题进行了提炼总结.研究表明:布置两道防渗墙时宜采用主墙廊道式、副墙插入式布置;廊道与防渗墙连接采用倒梯形刚性接头更为合适,廊道与两岸平洞结构分缝宜深入基岩一定距离;廊道或防渗墙周围需设置高塑性黏土区,并在主防渗墙廊道、副防渗墙与土心墙连接部位铺设土工膜,下游侧设置反滤层保护.研究成果可为深厚覆盖层上高土石坝防渗墙与土心墙采用廊道式连接的构造设计提供有益参考.

钢轨抗拉强度高(≥880 MPa)、抗弯性能好(工字型截面),将大截面抗滑桩中的纵向受力钢筋替换为旧钢轨,可形成具有抗滑能力强、投资节省的钢轨抗滑桩.通过查阅相关文献、规程规范和技术研发,形成了钢轨抗滑桩专利技术,它成功解决了大截面钢轨抗滑桩应用中旧钢轨强度取值较难、钢轨与混凝土握裹力不足、鱼尾板连接刚度不够且连接处强度低等限制大规模工程应用的关键技术问题.将大截面钢轨抗滑桩成功应用于构皮滩水电站石棺材崩坡积体治理.监测资料表明滑坡体变形较小,建成后经过2014年约100年一遇暴雨考验和近8年的安全运行,证明了大截面钢轨抗滑桩在大型滑坡治理中具有广阔的应用前景.

磁电阻率法是通过供电期间观测水库研究范围内总磁场或一次磁场的分布规律,以此研究水库渗漏目标的导电性能和导磁性能,实现探测渗漏通道的一种物探方法.为准确探测水库渗漏通道,首先根据水库现场地形地质条件、渗漏点分布、建筑物布置等,确定测量范围,布置测量点位;其次,按照预先设定的测量点位,采集测点磁场和测区背景磁场;然后,对比理想磁场与实际采集的磁场数据,反演电流分布模型,推得水库最为可能的渗漏通道的位置及高程.在国内某面板堆石坝坝基渗漏、某水库左岸山体渗漏探测中的应用成果表明,磁电阻率法具有不受探测深度限制、适用面广、准确度好等优点,可作为其他渗漏探测方法的有益补充.

根据地下与地面核电厂放射性废水迁移防护条件,充分考虑放射性废水地下迁移的影响因素,确定地下核电厂放射性废水迁移的防护措施.完全保留地面核电厂对放射性废水的所有安全防护措施,充分利用地下核电厂岩体的天然防护性能,通过在地下洞室周围岩体内增设封闭、疏干等工程措施,阻断放射性废水地下迁移的通道,同时设置收集、处置、监测系统.经数值计算分析,上述防护措施效果显著,地下核电厂严重事故工况下可能产生的放射性废水处于受控状态.

石棺材崩坡积体地质条件复杂,且曾发生过变形,本次边坡开挖将挖除坡脚压重、抗滑桩、档墙、格构等支护措施,对石棺材崩坡积体产生强烈的扰动,可能再次引发变形体变形.通过定性分析、定量计算、方案对比、数值分析确定了该崩坡积体的稳定性和针对性治理措施.监测结果表明治理措施效果较好,对类似工程有参考价值.

In order to understand the long-term performance of the pre-stressed anchorage cables installed in high slope of ship-lock of Three Gorges Project, the statistical analysis on the pre-stress variation process was carried out on the basis of the 15 years'monitoring data from 73 anchorage cables. The magnitude and distribution characteristic of the pre-stress loss at the locking moment and after the locking till December of 2014 are presented. The mode of the sequential curve of pre-stress loss after the locking are divided and the evolution laws under different modes are summarized and compared. The 3-stage pattern is the most representative, namely the abrupt spurt stage, randomly up-down attenuation stage and periodically stable fluctuation stage. The reason and influential factors of pre-stress loss are summarized in terms of different stages. The relationship between the pre-stress loss and the stability of slope is briefly discussed.

介绍了声波层析成像技术(声波CT)的基本原理,并以某水电站大坝建基面下的防空洞探测为实例,利用声波层析成像技术反演确定了该部位的波速分布情况,根据波速分布划分出波速异常带,确定了防空洞的空间展布范围与规模,为后续处理方案提供了科学的依据.

The strengthening grouting of Danjiangkou dam heightening project requires great effort because it is carried out in conditions of reservoir high water head,developed micro-fissures and multiple groutings. In order to explore an economic and effective grouting method,current methods of curtain grouting in the presence of high water head are analyzed. On this basis,a detailed introduction of compound grouting test design,key construction technologies and inspection after grouting is given. The test results are analyzed in terms of pressurized water data,acoustic wave test,and fatigue pressurized water. Results reveal that cement-chemical compound grouting is effective,saves investment and shortens construction period. It is a good example for other engineering design and construction for curtain grouting under high head.

The arch dam of Jinping I hydropower station is on obvious high ground area, and the foundation rock masses may relaxed while excavating. Limit tensile strain is put forward to be relaxation criterion. By three-dimensional elastic-plastic finite element method analyzing, and imitating the dam excavating steps, the maximum principle strain of the dam foundation rocks is obtained. The research indicates that the maximum principal strain of upstream side is greater than that of downstream side commonly, and some area would relaxed, with 41m maximal relaxed depth. By engineer analogical research with Xiaowan arch dam foundation rock mass, which have relaxed while excavating, the calculate method and criterion of this paper are reliable, and they can provide reference for engineer design.

The strengthening grouting for the curtain of Danjiangkou dam heightening works is carried out in fine crevice developed rocks and re-grouted rock mass under high water head,which is complicated technologically.The difficulties and features of strengthening grouting under high water head of Danjiangkou Reservoir are introduced.In order to explore the economic and effective grouting mode and method,the experiment schemes are deigned;the grouting effect of different grouting modes,coagulation time and segment lengths are analyzed.The experiment of cement slurry diffusion is carried out and some key technical problems in the propylene hydrochloride grouting are studied.The economic and effective grouting mode,method and quick construction technology aimed at the characteristics of strengthening grouting technology of curtain with high water head of Danjiangkou Dam are determined.