Theory and Application of System Integration for Real-Time Monitoring of Core Rock-Fill Dam Filling Construction Quality

The theory and method of system integration for the real-time monitoring of core rock-fill dam filling con- struction quality are studied in this paper. First, the importance analysis of system integration factors is carried out with the analytic hierarchy process. Then, according to the analysis result of integration factors, the conceptual model of system integration is built based on function integration, index integration, technology integration and information integration, the index structure of core rock-fill dam filling construction quality control is constructed and the method of function integration and technology integration is studied. The mathematical model of process monitoring is built according to monitoring objective, process and indexes. Research results have been applied in Nuozhadu core rock-fill dam construction management, realizing system integration through building appropriate monitoring work flow and comprehensive information platform of digital dam.

Optimizing Earth Allocation for Rock-Fill Dam Construction

An optimal allocation of earth is of great significance to reduce the project cost and duration in the construction of rock-fill dams. The earth allocation is a dynamic system affected by various time-space constraints. Based on previous studies, a new method of optimizing this dynamic system as a static one is presented. In order to build a generalized and flexible model of the problem, some man-made constraints were investigated in building the mathematic model. Linear programming and simplex method are introduced to solve the optimization problem of earth allocation. A case study in a large-scale rock-fill dam construction project is presented to demonstrate the proposed method and its successful application shows the feasibility and effectiveness of the method.

The Deformation and Stress Analysis of Na Ba Reservoir Concrete Face Rock-Fill Dam

Based on the APDL （ANSYS Parametric Design Language） and combined with the actual project related to parameters of filling material, imported Duncan-Chang constitutive model which has been widely applied in soil mass and rock-fill in the ANSYS software. With the three-dimensional nonlinear finite element analysis by the mid-point incremental method, what have been computed are the deformation and stress analysis ofNa Ba reservoir CFRD （Concrete Face Rock-fill Dam） in filling period. The calculation results provide practical reference for the dam during construction safety filling stress and deformation analysis and real-time monitoring.

Comparison between the Isotope Tracking Method and Resistivity Tomography of Earth Rock-Fill Dam Seepage Detection

This paper compares the different inversion results of three different earth rock-fill dam models with the actual leakage passages by performing isotope tracing tests and resistivity tomographic tests. The accuracy of the experimental results is evaluated, and the characteristics of these two methods are analyzed. As a result, some significant references are offered for earth rock-fill dam’s hidden defects detection. The experimental results show that the leakage and the direction of the seepage can be judged by isotope tracing tests, meanwhile, the degree of the leakage can be confirmed through the determination of the horizontal seepage velocity and the vertical seepage velocity, but it is difficult to properly determine the position of leakage passages and the range of leakage. Relatively speaking, the positions of the leakage passages can be accurately and directly displayed through resistivity tomographic tests. The experiment results show that the resistivity tomographic method is much better than isotope tracing method with regard to earth rock-fill dam’s hidden defects detection, and the resistivity tomographic method expresses much more convenience and much higher precision than isotope tracing method.

Application of 3D Electrical Resistivity Tomography for Diagnosing Leakage in Earth Rock-Fill Dam

The leakage occurs during operation of the dam in Liuhuanggou reservoir. It’s a threat to the safety of the people’s lives and property in downstream. In order to eliminate the hidden danger of reservoir, ensure the safety of the dam, play better the function of flood control and water storage of the reservoir etc., we apply the 3D electrical resistivity tomography detecting technology and volume rendering image processing technology, make the measurement in field, process the data and combine the field survey to find out the leakage channels inside the dam. The results show that the 3D resistivity images appear the low resistivity zone corresponding with the leakage channels. There are two main leakage channels that come from different location inside the dam. It is feasible to diagnose the leakage in earth rock-fill dam by applying 3D electrical resistivity tomography.

堆石混凝土坝概述及下一代混凝土坝施工技术展望

Over the past few decades,one of the most significant advances in dam construction has been the inven-tion of the rock-filled concrete(RFC)dam,which is constructed by pouring high-performance self-compacting concrete(HSCC)to fill the voids in preplaced large rocks.The innovative use of large rocks in dam construction provides engineers with a material that requires less cement consumption and hydration heat while enhancing construction efficiency and environmental friendliness.However,two fundamental scientific issues related to RFC need to be addressed:namely,the pouring compactness and the effect of large rocks on the mechanical and physical properties of RFC.This article provides a timely review of fundamental research and innovations in the design,construction,and quality control of RFCdams.Prospects for next-generation concrete dams are discussed from the perspectives of envi-ronmental friendliness,intrinsic safety,and labor savings.

Prediction of Concrete Faced Rock Fill Dams Settlements Using Genetic Programming Algorithm

In the present study a Genetic Programing model (GP) proposed for the prediction of relative crest settlement of concrete faced rock fill dams. To this end information of 30 large dams constructed in seven countries across the world is gathered with their reported settlements. The results showed that the GP model is able to estimate the dam settlement properly based on four properties, void ratio of dam’s body (e), height (H), vertical deformation modulus (Ev) and shape factor (Sc) of the dam. For verification of the model applicability, obtained results compared with other research methods such as Clements’s formula and the finite element model. The comparison showed that in all cases the GP model led to be more accurate than those of performed in literature. Also a proper compatibility between the GP model and the finite element model was perceived.

基于FOA-RF算法的心墙砾石土压实质量预测模型

针对随机森林(RF)算法预测心墙砾石土压实质量存在决策树数量选取缺乏深入研究和忽视P0.075质量分数对压实质量影响的问题,提出了一种基于果蝇优化(FOA)算法的随机森林算法(FOA-RF算法),并构建了基于FOA-RF算法的心墙砾石土压实质量预测模型(FOA-RF模型)。该模型一方面通过对料源参数和干密度进行相关性分析,新增了P0.075质量分数作为模型的输入参数;另一方面利用FOA算法对随机森林进行优化,解决了RF算法难以取得决策树数量最优解、没有同时考虑决策树数量与随机特征数影响的问题。以西南某在建砾石土心墙堆石坝工程为例,分别应用基于传统RF、BP神经网络、多元线性回归的预测模型和FOA-RF模型进行压实质量预测。结果表明,FOA-RF模型在预测精度上具有优越性,并基于该模型开发压实质量预测模块,将该模块嵌入碾压质量实时监控系统中可实现压实质量的实时预测。

阳蓄电站下水库大坝沥青混凝土心墙施工配合比试验研究

沥青混凝土心墙是土石坝坝体防渗的关键性、隐蔽性工程,施工质量控制标准要求高。沥青混凝土的力学性质不仅与温度变化、工作条件有密切的关系,还取决于所用原材料的特性、配合比以及施工质量等因素,因此,选择优异性能及适合施工的沥青混凝土配合比就显得尤为重要。本文结合阳江抽水蓄能电站下水库大坝沥青混凝土心墙施工实例,对沥青混凝土心墙原材料的选择、室内配合比试验和现场铺筑试验情况进行了介绍。通过沥青混凝土物理力学及变形性能试验检测、试验结果验证,选择出最佳的沥青混凝土心墙施工配合比,该配合比在工程实施中得到了有效的验证。

那榔水库黏土心墙堆石坝施工关键技术要点

黏土心墙是以黏性土料作为坝中央防渗体,对坝体渗透与稳定起控制作用,研究黏土心墙施工技术对坝体稳定有重要意义。以云南广南县那榔水库堆石坝为例,对其黏土心墙筑坝主要研究了心墙料的选取、开采,坝体填筑方案、筑坝材料检测,以及坝壳料、心墙防渗料、反滤料的关键施工技术要点。实践表明:该套施工技术要点科学合理,可有效满足那榔水库粘土心墙堆石坝设计与施工的要求。总结形成了一套完善系统的心墙施工技术方法体系。

Parameter sensitivity and inversion analysis of a concrete faced rock-fill dam based on HS-BPNN algorithm

Considering the complex nonlinear relationship between the material parameters of a concrete faced rock-fill dam(CFRD) and its displacements, the harmony search(HS) algorithm is used to optimize the back propagation neural network(BPNN), and the HS-BPNN algorithm is formed and applied for the inversion analysis of the parameters of rock-fill materials. The sensitivity of the parameters in the Duncan and Chang's E-B model is analyzed using the orthogonal test design. The case study shows that the parameters φ0, K, Rf, and Kb are sensitive to the deformation of the rock-fill dam and the inversion analysis for these parameters is performed by the HS-BPNN algorithm. Compared with the traditional BPNN, the HS-BPNN algorithm exhibits the advantages of high convergence precision, fast convergence rate, and strong stability.

Key technical problems of extra-high concrete faced rock-fill dam

This paper summarizes the main technical points related to 100 m-height-scale concrete faced rock-fill dams and analyzes the main problems and their causes occurring during construction of 200 m-height-scale concrete faced rock-fill dams. This paper has raised the key technical problems which need to study for construction of 300 m-height-scale concrete faced rock-fill dams based on the main experiences on the extra-high concrete faced rock-fill dams built after the year of 2000.

基于实测资料的超高心墙堆石坝拱效应分析

基于某心墙堆石坝长序列实测监测数据,以土压力、心墙沉降、水压力、孔隙水压力等测值定量计算分析结果为依据,以拱效应系数、上游水压力与心墙竖向应力比值、心墙孔隙水压力与心墙竖向应力比值等指标作为分析评判标准,提供了一种基于实测资料的超高心墙堆石坝拱效应分析方法和算例,系统分析了该高心墙堆石坝拱效应程度、分布规律及心墙发生水力劈裂的可能性,并与该心墙堆石坝数值计算结果进行对比分析和验证。分析结果表明,基于实测资料的计算分析结果与数值计算分析结果具有一致性,该分析方法具有合理性和可行性,可为同类工程的设计、施工和运行提供借鉴和参考。

Influence of soft rock-fill material as dam embankment with central bituminous concrete membrane

This paper demonstrates the difficulties in determining the relevant material parameters for a valuation of the deformation behavior of the up-and downstream dam shell by means of an embankment dam of medium height.Laboratory as well as field tests on solid rock-fill material were performed before the beginning of construction.During the construction the properties of the available rock-fill changed from solid to soft materials.This gave rise to the necessity of adjusting the dam design of the downstream dam shoulder.Several times higher dam settlements as well as significant differential settlements between the up-and downstream dam shell were observed during construction and operation.Apart from this situation,the dam has been operated for nearly 20 years and the behavior of the water barrier has been very good.

ON THE CALCULATION OF FLOW OVER AND THROUGH A ROCK-FILL DAM

For an overtopped rock-fill dam, the flow field consists of open flow and seepage flow, which have different properties. The overflow is characterized as variable flow and the seepage flow is not the Darcy flow, but non-Darcy flow. For the analysis of the flow characters, using the energy theory and the FEM, the author presents a method to calculate the combined flow (i. e. flow over and through a dam ) in this paper. The experimental work shows that, the calculated results agree well with the experimental ones.Therefore, it is not only possible, but also feasible to solve this problem with the presented method.

混凝土心墙堆石坝加固施工模拟

针对某在建的混凝土心墙堆石坝,基于ABAQUS平台开发了模拟堆石体非线性关系的邓肯-张E-B和E-ν子程序,用于模拟混凝土心墙堆石坝加固施工过程。通过3种计算方案对该心墙堆石坝加固填筑及蓄水全过程进行三维仿真模拟,结果表明:防渗体造孔部分的施工质量对现浇防渗体的应力～变形性状影响较大,应尽可能提高防渗体造孔部分的施工质量;防渗墙弹性模量采用上限值或采用下限值计算得出的结果都与防渗墙实测值比较接近,说明采用上限值及下限值计算出的结果范围可以合理预测防渗墙的真实变形。所得结论为该心墙堆石坝的加固施工效果评价及后期监测方案的优化提供了依据。

基于ABAQUS平台的邓肯-张E-B和E-ν模型程序开发

基于ABAQUS平台并利用UMAT子程序接口开发了邓肯-张E-B和Eν-模型程序,开发的程序可在一个模型中包含邓肯-张E-B和E-ν2种不同的本构模型.应用该程序对一已建混凝土心墙堆石坝进行了变形及稳定的数值计算,并与现场实测结果进行了比较.结果表明,数值计算与现场实测的变形变化趋势较为一致.该结果验证了所研制程序的正确性,说明该程序可以用于分析实际工程问题.

基于CATIA的心墙堆石坝三维可视化交互系统

目前大坝施工仿真建模中多是基于Geographic Information System(GIS)或3DS MAX软件构建的施工场景,其三维模型存在精度不高,不易修改,相似模型也不能重复利用等问题。本文将CATIA引入心墙堆石坝施工仿真建模中,即利用CATIA的三维建模技术构建了心墙堆石坝的三维施工场景。关键技术包括骨架设计技术、参数化技术、知识工程技术和设计过程模块化技术,并通过三维数字建模来模拟整个建筑物的信息。以某心墙堆石坝为例,建立了基于CATIA的心墙堆石坝施工仿真系统平台,实现了基于Brower/Server(B/S)的堆石坝施工场景的远程交互,可为堆石坝施工管理提供理论与技术支持。

土石坝心墙水力劈裂的非饱和土固结方法研究

针对土石坝心墙土在初次蓄水前为饱和度高于80%的非饱和土,提出了研究心墙水力劈裂问题的非饱和土固结简化计算的有效应力分析方法。该方法不仅可反映孔隙中气体对水压上升的影响,还可合理分析心墙土的渗透性、初始饱和度和蓄水速度等心墙水力劈裂的影响因素。以糯扎渡堆石坝为例,研究发现:填筑竣工时,尽管心墙中部水压很高,但心墙仍处于非饱和状态;初次蓄水时,上游水压力不能及时渗入心墙内部,形成了心墙内外的水压力突变,可导致心墙水力劈裂的发生。同时研究发现:提高心墙的渗透系数、提高心墙填筑土的初始饱和度、在初次蓄水时,放慢蓄水速度等均可防止心墙水力劈裂的发生。因此非饱和土固结简化计算的有效应力方法分析水力劈裂问题是合理的,它可为实际心墙土石坝预防水力劈裂问题提供科学依据,并可进一步提高土石坝设计水平。

糯扎渡高心墙堆石坝抗震安全研究与设计

糯扎渡高心墙堆石坝最大坝高261.5m,在当前同类坝型中居世界第三、国内第一,坝址位于我国西南强震区,区域地质条件复杂,地震频繁、强度大,因此大坝的抗震安全至关重要。国内外可借鉴的经验较少,因此对大坝抗震安全相关的关键技术问题开展了大量的深入研究,并应用到工程实际中。本文介绍了糯扎渡高心墙堆石坝抗震安全相关的课题研究成果及最终的抗震设计方案,为同类工程的抗震设计及研究工作提供了参考。