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.

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.

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.

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Flow-3D尾矿库漫顶溃坝过程数值模拟

尾矿库是一个具有高势能的危险源,一旦发生溃坝,将对下游居民的生命财产造成严重威胁。为了提高尾矿库溃坝灾害预测与应急保障能力,以某尾矿库为工程背景,开展尾矿库溃坝的室内模型实验,并结合Flow-3D数值仿真技术对尾矿库漫顶溃坝后尾砂流的演进过程进行深入研究。将室内模型实验和数值模拟结果相互对比,溃坝过程基本吻合,验证了较小缩比尺模型实验的准确性以及数值模拟的可靠性。数值模拟研究结果表明:溃水的淹没高度和断面流量随溃坝时间的变化整体表现为前期快速增长及后期的较缓下降,且随着演进距离的增加,淹没高度和断面流量峰值都明显降低;下游地形影响溃坝尾砂流的流速和演进方向,溃坝尾砂流在下游弯道处出现“爬高”现象,弯道两岸淹没高度不同,弯道凹岸淹没高度高于另一侧;沟谷与河道的连接处,溃水向河道上下游两边扩散,在河道入口处形成“冲积扇”堵塞河道。

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.

尚义碾压混凝土重力坝溢流坝段温控仿真分析

由于碾压混凝土坝浇筑高程上升快、散热不及时,再加上碾压混凝土浇筑初期抗拉强度低,在混凝土坝冷却降温过程中会出现较大拉应力,尤其对于寒冷地区冬季气温低,降温速度过快,内外温差大,坝体的开裂问题更为严峻和突出。通过三维有限元软件模拟尚义碾压混凝土重力坝溢流坝段施工期和运行期,分析溢流坝段的温度场和温度应力场规律,尤其对采用高等级混凝土的溢流面部分进行重点研究,改进相应的温控措施。结果表明,寒冷地区碾压混凝土坝温控问题突出,在只有表面保温措施下,夏季浇筑的坝体混凝土温升过高,坝体内部温度应力存在超标,与坝体同步浇筑的溢流面C30混凝土温度和温度应力大幅超出允许范围;采用改进的温控措施后,坝体整体温度应力得到有效控制,调整浇筑计划后的溢流面温度和温度应力状况大幅改善,降低了其在寒冷天气开裂的风险。

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.

暴雨山洪与山坪塘漫坝多灾害耦合风险分析

为研究强降雨下山洪与漫坝耦合灾害对下游居民的影响程度和范围,应用HEC-RAS软件构建暴雨山洪与山坪塘漫坝多灾害耦合模型。首先,以重庆市巴南区某山坪塘为研究对象,根据巴南区暴雨强度公式设计不同重现期的降雨雨型;其次,借助数字高程数据对山坪塘进行原始构建,采用参数化模型对溃坝楔口参数进行预测,结合物理溃坝机制模拟漫坝过程;最后,选取洪水深度、洪水流速和洪水滞留时间等3个评价指标进行洪水风险分析。研究结果表明,突发强降雨下的山洪形成迅速且山坪塘发生漫坝的机率极大;山坪塘漫坝会加重附近区域的洪水风险等级。

高寒地区细粒尾矿堆坝方案研究

以小兴安岭地区某尾矿库为例,开展了全尾矿湿排堆坝、全尾矿池填法堆坝和旋流器分级堆坝试验。结果表明,旋流器分级堆坝具有对比优势,可有效提高坝前尾矿的排水固结能力、增大干滩长度和坝前区域尾矿的强度,同时可形成较大的沉积滩坡度、保证安全超高,改善坝体渗流条件、提高滩面承载能力和堆坝效率。通过细化旋流器分级堆坝工艺,采用非冬季堆坝、冬季放矿的宽体子坝堆筑方案可在一定程度上解决沉积滩含水量大、承载力低、无法尾砂堆筑子坝等问题,但在粗砂利用率、高等级尾矿库子坝宽度、冻土发育等方面仍存在不足。最终结合旋流器分级宽体子坝和模袋法两种堆坝工艺,有效解决了尾矿库堆坝所面临的主要问题,可作为高寒地区细粒尾矿堆坝的高效方案加以推广。

赣州市章江八境湖拦河坝水闸工程结构安全复核分析

赣州市章江八境湖拦河坝水闸工程长时间使用和磨损导致水闸设备老化,对章江八境湖拦河坝水闸工程的拦河闸结构进行安全复核。复核结果表明,拦河闸在部分工况下闸基抗滑稳定安全系数不满足规范要求,应力满足规范要求,闸墩结构强度满足规范要求。因此,亟需对本工程拦河闸进行除险加固。

极端天气对于溢流坝段温度与应力影响分析

以某水电站为对象,采用数值模拟的方式,模拟了大坝在常规运行期和极端天气下的温度场和应力场分布。研究表明:在常规运行期中主要是夏季大坝温度应力较大,其中变电洞左侧顶部区域的拉应力最大,达2.64 MPa,超过混凝土抗拉强度。在极端天气影响下,高温和泄水的条件下,此处的拉应力将进一步提高,达2.93 MPa,极易产生裂缝。冬季寒潮对于大坝表面混凝土的温度和应力影响较大,其中反弧段附近的混凝土拉应力从1.6 MPa增至4.0 MPa,超过抗拉强度。因此极端天气加剧了温度变化对于大坝的影响,主要改变大坝表面温度场的分布,形成更大的温度应力,危害结构安全,需得到足够重视。

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.

大盈江四级水电站溢流坝水力特性研究

文章针对大盈江四级水电站设计阶段提出的两种溢流坝布置方案(方案一:溢流坝+右侧泄洪冲沙底孔;方案二:溢流坝+左侧泄洪冲沙闸+右侧泄洪冲沙底孔)进行了计算流体力学数值模拟(CFD),结合水工模型试验结果与CFD数值模拟结果,分析了溢流坝两种布置方案的流态分布规律和消能防冲效果。计算结果表明,在流态规律和流速分布及消能防冲效果方面,方案一优于方案二;方案二较方案一更有利于库区排沙减淤,泄流能力较强。通过控制闸孔启闭模式可调整方案二相应出流流态,能较好地适应大盈江高含沙量的水流条件。

河道滚水坝对水体溶解氧及有机物浓度的影响

为定量研究河道滚水坝对水体溶解氧和高锰酸盐指数的影响,选择一城市河道小型滚水坝,在坝前和坝下设监测点,定期监测水质变化。结果表明:污染河水流经小型滚水坝后,水中溶解氧浓度平均增加了1.75 mg/L,夏季增加的最为明显,最大增加值发生在7月,达2.43 mg/L;水中部分污染物的降解使水体的CODMn负荷减轻,滚水坝对CODMn的平均去除率为3.81%。滚水坝对城市河道污染水体可起到一定的净化作用。

溢流面板堆石坝泄槽底板稳定及结构应力分析

基于推导的泄槽底板抗滑稳定安全系数计算式,运用正交设计的直观分析法进行底板稳定性敏感性分析,结果表明阻滑板长度、底板长度和溢流平均速度是影响底板稳定的重要因素.从底板的抗滑稳定角度,分析及计算底板最大允许流速范围为15.33～40.67m/s.最后以实际工程为例,分析了泄槽底板在单一阻滑板加固作用下的抗滑稳定性以及阻滑板与底板的应力.