舒家山尾矿库二期扩建坝安全运行监测分析

鉴于目前对尾矿库二期加坝监测没有一个统一的规律可寻,其根本原因在于尾矿库明显的个案性,另一点是缺乏已建类似坝的相关资料,因而给监测分析带来很大困难。本文结合舒家山尾矿库二期扩建坝已运行二年,通过对坝体设计和监测资料的整理分析,对坝体的安全运行状态及变化规律做出判断,为今后尾矿库安全生产提供一个科学参考。     

小湾水电站低高程坝基开挖卸荷松弛机理试验研究

小湾电站低高程坝基开挖过程中,表层岩体卸荷松弛强烈,主要形式有沿已有裂隙地错动、张开和扩展,及因新生破裂而松弛。后者主要包括:葱皮现象、板裂现象和岩爆现象。试验测试表明,开挖面附近微新岩石为坚硬极坚硬岩石,但其初始损伤明显,其损伤发展启动应力在5.2~12.4MPa之间,抗拉强度在3~6MPa之间,这是坝基表层岩体卸荷松弛强烈的物质基础;坝基面爆破开挖的应力集中和爆炸作用影响是坝基岩体卸荷松弛强烈的岩石力学环境条件。     

寒区平原水库土坝护坡冻害防治技术

根据近年来冻土力学、冰工程学等研究成果,简述了寒区原水库土坝护坡构筑物冻害防治技术的主要内容,包括平原水库土坝护坡工程冻害破坏规律,给出了土坝护坡冻害防治措施、防冰措施、抗冻胀设计参数的确定、抗冰推护坡稳定计算等,可供工程设计人员参考。     

Numerical modeling of soil–structure interface of a concrete-faced rockfill dam

Concrete-faced rockfill dams (CFRD) are widely used in large-scale hydraulic projects. The face slab, the key seepage-proof structure of great concern, has a strong interaction with the neighboring gravel cushion layer due to a significant difference in their stiffness. An elasto-plasticity damage interface element, a numerical format of the EPDI model, is described for numerical analysis of a CFRD that can trace the separation and re-contact between the face slab and the cushion layer at the interface. As verified by simulating slide block and direct shear interface tests, this element was confirmed to capture effectively the primary monotonic and cyclic behaviors of the interface. This element can easily be extended to the finite element method (FEM) programs that involve the Goodman interface element. The analysis of a typical CFRD showed that the interface model describes a significant effect on the stress response of the face slab under different conditions, including dam construction, water storage, and earthquake. Treatments of the cushion layer, such as an asphalt layer, changed the behavior of the interface between it and the face slab, which resulted in a significant effect on the stress response of the face slab. The top of the face slab exhibited a significant separation from the cushion layer during construction, induced mainly by construction of the neighboring dam body.     

爆破直采技术在面板堆石坝工程中的应用

面板堆石坝的坝料开挖直接制约工程进度,按传统工艺开挖费时费工,严重影响施工进度,本工程在利用坝体级配料开挖中采用爆破直采技术,加快了坝料开采速度,效果显著。经过爆破试验,优选爆破参数,为获取粒径与级配符合设计要求及成本低廉的坝料创造了有利条件。详细介绍了试验过程,并对试验结果进行了分析。     

核电厂选址地震安全评价中的发震构造与能动断层

本文主要根据《黄河黑山峡河段地震地质补充论证工作报告》1,对黄河黑山峡河段大柳树坝址区主要地震地质问题,包括1709年中卫7?级地震的地表破裂带长度,F201断层的规模,坝址区F3、F7断层晚更新世以来是否被F201断层“牵动”,坝址区不同级别断层的深浅构造关系等主要方面的研究进展作一概要介绍。2     

小湾电站边坡卸荷三维有限元模拟

应用3D-Sigma软件对小湾右岸边坡的河谷下切卸荷过程进行了三维有限元弹塑性模拟.通过缩小单元规模,对边坡坡面下180 m范围内的应力、位移情况进行了详细的模拟.模拟结果表明:由横河陡倾分布的坚硬岩层构成的边坡在河谷下切形成坡体卸荷的过程中,坡体内产生的拉应力区较小;坡内岩体变形和应力分布主要受软弱面分布、微地形、主压应力分异、剪应力集中影响;卸荷的影响深度约在坡面下120m左右及软弱面附近120 m范围内,这些区域是边坡支护设计的重点.     

Solving multicollinearity in dam regression model using TSVD

Targeting the multicollinearity problem in dam statistical model and error perturbations resulting from the monitoring process,we built a regularized regression model using Truncated Singular Value Decomposition(TSVD).An earth-rock dam in China is presented and discussed as an example.The analysis consists of three steps:multicollinearity detection,regularization pa-rameter selection,and crack opening modeling and forecasting.Generalized Cross-Validation(GCV) function and L-curve criterion are both adopted in the regularization parameter selection.Partial Least-Squares Regression(PLSR) and stepwise regression are also included for comparison.The result indicates the TSVD can promisingly solve the multicollinearity problem of dam regression models.However,no general rules are available to make a decision when TSVD is superior to stepwise regression and PLSR due to the regularization parameter-choice problem.Both fitting accuracy and coefficients’ reasonability should be considered when evaluating the model reliability.     

KL植物胶在人工填筑堆石层钻进中的应用

针对伊朗TALEGHAN水库大坝观测仪器孔在松散、架空、透水性极强的堆石层中钻进存在的取心困难、泥浆漏失严重、孔壁稳定性差等问题,引进以KL植物胶为主要原料的处理剂配置成无固相冲洗液和不分散低固相泥浆,并配合一系列堵漏材料在现场的综合应用,取得了良好的钻进效果。介绍了KL植物胶的配方、泥浆性能指标及护壁堵漏效果,为今后类似地层钻孔提供了可借鉴的经验。     

Settlement analysis of the Shuibuya concrete-face rockfill dam

Settlement is one of the most important deformation characteristics of a high concrete-face rockfill dam (CFRD) and is regarded as a key indicator of dam safety. The time-dependent settlement behavior of the Shuibuya CFRD is studied on the basis of in situ settlement-monitoring records and displacement back-analysis. The goal of this work is to characterize actual deformation of the dam and to verify the back-analysis method used in this paper. The settlement-monitoring records were from seven control stations at the crest and 38 monitoring points inside the body of the dam and covered the construction period, the initial filling of the reservoir and 2 years of operation. A displacement back-analysis for parameters is performed by hybrid generic algorithms (HGAs) and finite element method (FEM). Comparative studies of monitoring data and back-analysis show good agreement between measured settlements and computed settlements. Furthermore, the deformation in the next 3 years is predicted on the basis of back-analysis. Overall, it is demonstrated that the deformation of the Shuibuya CFRD is basically stable and that the technique used to control the dam deformation is successful.