Safety monitoring and stability analysis of left abutment slope of Jinping Ⅰ hydropower station

Safety monitoring and stability analysis of high slopes are important for high dam construction in high mountainous regions or precipitous gorges. In this paper, deformation characteristics of toppling block at upper abutment, deforming tensile rip wedge in the middle part and deep fractures are comprehensively analyzed based on the geological conditions, construction methods and monitoring results of left abutment slope in Jinping Ⅰ hydropower station. Safety analyses of surface and shallow-buried rock masses and the corresponding anchorage system are presented. The monitoring results indicate that the global stability of the large wedge block in the left abutment is effectively under control, and the abutment slope is stable in a global sense. After the completion of excavation, the deformations of toppling block at the top of the slope and deep fracture zone continue at a very low rate, which can be explained as 'rock mass creep'. Further monitoring and analysis are needed.

Study on Safety and Stability Evaluation of Waste Disposal Field of a Hydropower Station Based on <i>In Situ</i>Monitoring

Reasonable site selection, blocking to meet design standards, interception and drainage and other protective measures are the basic conditions for not causing disaster in slag disposal site. A hydropower station is located in mountainous area, the amount of slag abandoned is large, the grade of slag disposal field is high, and the site selection is difficult. On the basis of in Situ deformation monitoring, the slope stability of slag disposal site is calculated by Swedish arc method through the analysis of the scale, grade, site selection, surrounding environment, cut and discharge, blocking and protection design standards of slag disposal site. Under normal and abnormal operating conditions, the slope stability of slag disposal site meets the requirements of the code, and the results of in Situ deformation monitoring verify the calculation results of slope stability of slag disposal site by Swedish circular arc method.

Measures for controlling large deformations of underground caverns under high in-situ stress condition--A case study of JinpingⅠhydropower station

The Jinping I hydropower station is a huge water conservancy project consisting of the highest concrete arch dam to date in the world and a highly complex and large underground powerhouse cavern. It is located on the right bank with extremely high in-situ stress and a few discontinuities observed in surrounding rock masses. The problems of rock mass deformation and failure result in considerable challenges related to project design and construction and have raised a wide range of concerns in the fields of rock mechanics and engineering. During the excavation of underground caverns, high in-situ stress and relatively low rock mass strength in combination with large excavation dimensions lead to large deformation of the surrounding rock mass and support. Existing experiences in excavation and support cannot deal with the large deformation of rock mass effectively, and further studies are needed. In this paper, the geological conditions, layout of caverns, and design of excavation and support are first introduced, and then detailed analyses of deformation and failure characteristics of rocks are presented. Based on this, the mechanisms of deformation and failure are discussed, and the support adjustments for controlling rock large deformation and subsequent excavation procedures are proposed. Finally, the effectiveness of support and excavation adjustments to maintain the stability of the rock mass is verified. The measures for controlling the large deformation of surrounding rocks enrich the practical experiences related to the design and construction of large underground openings, and the construction of caverns in the Jinping I hydropower station provides a good case study of large-scale excavation in highly stressed ground with complex geological structures, as well as a reference case for research on rock mechanics.

Key techniques for evaluation of safety monitoring sensors in water conservancy and hydropower engineering

For the evaluation of construction quality and the verification of the design of water conservancy and hydropower engineering projects, and especially for the control of dam safety operation behavior, safety monitoring sensors are employed in a majority of engineering projects. These sensors are used to monitor the project during the dam construction and operation periods, and play an important role in reservoir safety operation and producing benefits. With the changing of operating environments and run-time of projects, there are some factors affecting the operation and management of projects, such as a certain amount of damaged sensors and instability of the measured data. Therefore, it is urgent to evaluate existing safety monitoring sensors in water conservancy and hydropower engineering projects. However, there are neither standards nor evaluation guidelines at present. Based on engineering practice, this study examined some key techniques for the evaluation of safety monitoring sensors, including the evaluation process of the safety monitoring system, on-site detection methods of two typical pieces of equipment, the differential resistor sensor and vibrating wire sensor, the on-site detection methods of communication cable faults, and a validity test of the sensor measured data. These key techniques were applied in the Xiaolangdi Water Control Project and Xiaoxi Hydropower Project. The results show that the measured data of a majority of sensors are reliable and reasonable, and can reasonably reflect the structural change behavior in the project operating process, indicating that the availabilities of the safety monitoring sensors of the two projects are high

Research on reform schemes of control methods of inlet gate in Jiaxin Hydropower Station

The simple gate control system which is made of traditional manual or proximity switch cannot meet the requirements of connecting with the computer monitoring system of hydropower station, it must be reformed. On the basis of the integrated analysis for small hydropower station, the paper discussed the singlechip as the core to realize the methods of gate automatic control system in small hydropower station. The designs for hardware and software of gate control system were introduced. And the control system was reformed from customary manual control to computer automatic control. The simulation experiment shows that this scheme is feasible.

Research and Practice on the Crustal Deformation Mobile Monitoring Network Layout in the Hydropower Station Reservoir Area

According to the construction project of the crustal deformation mobile monitoring network in the cascade hydropower stations built in the lower reaches of Jinsha River,this paper analyzes the design ideas and layout principles of crustal deformation mobile monitoring used in the monitoring of reservoir induced earthquakes. This paper introduces three types of monitoring networks used in the Xiluodu reservoir and Xiangjiaba reservoir, as well as the work already undertaken,in order to provide a kind of reference for the related engineering construction and comprehensive monitoring of reservoir induced earthquakes.

Study on Seepage Control in Complicated Hydrogeological Conditions on the Right Bank of JinPing-I Hydropower Station

With consideration of the special hydrogeological conditions and layout characteristics of the hydraulic structures, the seepage control measures of dam abutment and underground powerhouse on the right bank of JinPing-I hydropower station is drawn up. Based on the three dimensional finite element analysis of seepage control with dry area virtual flow constant mesh analysis method, the rationality of the seepage control measures of dam abutment and underground powerhouse has been verified and the key factors affecting the effect of seepage have been compared. In combination with the curtain of dam abutment, the curtain of underground powerhouse is reasonable. The results showed that the steel liner of penstock after the curtain is necessary.

Practice of Centralized Control over Cascade Hydropower Stations

Isolated operation of hydropower stations on Wujinag River was seen disadvantages of low rate of water utilization and much loss of electricity caused by abandoned water during low load periods. To tackle the problem, centralized control over cascade hydropower stations is practiced with a considerable economic benef it gained.

Analysis of rockburst mechanism and warning based on microseismic moment tensors and dynamic Bayesian networks

One of the major factors inhibiting the construction of deep underground projects is the risk posed by rockbursts.A study was conducted on the access tunnel of the Shuangjiangkou hydropower station to determine the evolutionary mechanism of microfractures within the surrounding rock mass during rockburst development and develop a rockburst warning model.The study area was chosen through the combination of field studies with an analysis of the spatial and temporal distribution of microseismic(MS)events.The moment tensor inversion method was adopted to study rockburst mechanism,and a dynamic Bayesian network(DBN)was applied to investigating the sensitivity of MS source parameters for rockburst warnings.A MS multivariable rockburst warning model was proposed and validated using two case studies.The results indicate that fractures in the surrounding rock mass during the development of strain-structure rockbursts initially show shear failure and are then followed by tensile failure.The effectiveness of the DBN-based rockburst warning model was demonstrated using self-validation and K-fold cross-validation.Moment magnitude and source radius are the most sensitive factors based on an investigation of the influence on the parent and child nodes in the model,which can serve as important standards for rockburst warnings.The proposed rockburst warning model was found to be effective when applied to two actual projects.

汛期水风光多能互补动态调度模型研究

为充分利用水电站水库汛期在预报无洪水或小洪水时的调节能力,将汛期运行水位动态控制域对应库容作为调节风光运行的可用库容,在提高水库调节能力的基础上给出了考虑入库洪水实时状态的汛期水电站水库动态消纳风光调度模式,以风光出力期望值加水电出力之和与负荷偏差最小为目标,结合风光出力不确定性建立了汛期水风光多能互补动态调度模型,并以福建省水口水电站为例进行模拟调度计算。结果表明:所提动态消纳风光调度模式能够在保证防洪安全的前提下充分合理利用水位动态控制域内的调节能力来调节风光出力,使失负荷时段数和发电量缺口期望值相较于传统调度模式分别降低约37%和32%,水电站水库平均发电水头提高约4.39%,不仅可提高系统出力可靠性,且能增加系统运行效益。研究成果可为汛期调节风光出力提供参考。

基于云平台的热网智慧换热站监控系统

随着日益增长的集中供热面积及智慧城市的建设,针对换热站目前存在自动化程度不高、远程采集信息困难、热网调节波动大等问题,开发了基于云平台的换热站远程监控系统。通过智能DTU网关与PLC连接,将数据采集到服务器中,通过服务器之间数据传递,使用VS开发客户端及WEB发布。针对换热站二次网温度波动大问题,设计了模糊自适应PID控制器,通过仿真满足二次网水温控制要求。通过模拟测试,系统功能完善满足构建智慧热网的需要。

基于DS-InSAR的西南某电站库区形变监测及滑坡体识别

针对中国西南部水电站及其周边区域存在形变及滑坡隐患的问题,提出一种联合DS-InSAR技术和空间聚类的分析方法。采用DS-InSAR技术获取了澜沧江流域的某水电站及其库区的时序形变,并利用GPS监测数据对比验证。在此基础上,利用空间聚类方法绘制了滑坡多边形,识别了库区的潜在滑坡体。结果表明,DS-InSAR监测与GPS点的监测值误差范围为-4.73~4.33 mm/a,水电站大坝表面整体存在不同程度的形变特征。沿水流方向,库岸两侧呈现顺坡向形变的趋势。结合空间聚类统计方法成功识别出6处具有突出形变特征的区域,其中4处为古滑坡。该研究成果可为水利工程的稳定运行和地质灾害的预防提供依据,为识别、排查水电站及库区存在的安全隐患提供参考。

多开发主体梯级电站实时负荷控制模型研究

由于多开发主体下梯级水电站间不能共享实时负荷数据,上一级电站发电负荷变动常导致本级电站非正常弃水或低水位运行问题。为解决这个问题,提出了基于预测控制的多开发主体梯级电站实时负荷控制模型来控制水位。模型分为实时跟踪、预测控制和厂内负荷分配3部分。实时跟踪每1 h进行一次入库流量反推计算来推算预测入库流量序列;预测控制根据标准差选择不同流量递推模型推算入库流量;厂内负荷分配以耗水量最小进行负荷分配优化,实现上游电站负荷及发电流量未知情况下的梯级电站实时负荷分配并保持水位稳定。所提出的实时负荷控制模型应用于木里河梯级电站实时负荷分配,对多开发主体下流域梯级水电站实时负荷分配,维持水位稳定具有一定的指导意义。

水电站尾调室湿环境控制方案对比分析

尾调室作为水电站的重要组成部分,其热湿环境影响水电站的安全稳定运行。实际工程中发现,尾调室内起雾与冷凝现象严重,内部设备运行和工作人员健康受到影响。本文根据XLD水电站尾调室的实际情况,提出机械通风、冷却除湿、冷却除湿+机械通风3种湿度控制方案,并通过数值模拟的方法比较3种方案在夏季最不利条件下对湿环境的控制效果,寻找尾调室湿度控制的最优方案。结果表明:机械通风方案不能有效解决尾调室湿度过高的问题,端部及底部空气多处呈饱和状态;冷却除湿方案能起到一定除湿效果,但存在风流分布不均匀的现象,中部和端部相对湿度仍不满足要求;冷却除湿+机械通风方案能够使尾调室工作区湿度降至80%以下,室内空气温湿度分布较为均匀。

基于InSAR的乌东德水电站库区边坡形变监测及分析

水电站建成投产后,水库水位变化频繁,改变了库岸边坡原有的稳定性,易诱发边坡失稳破坏,从而对水电站的安全运行及周边居民区产生一定安全隐患。为了更好地掌握乌东德水电站蓄水过程中库区边坡的形变情况,通过SBAS-InSAR技术对该区域2020年5月至2022年8月间的升降轨哨兵数据进行解算,获取了研究区的地表形变特征;结合库水位变化情况、SAR数据反演出的边坡土壤含水量后向散射系数,对识别出的5处不稳定区域的形变机理进行分析。结果表明:运用升降轨InSAR可准确识别出库岸边坡的形变情况,研究区最大年平均沉降速率为-92 mm/a;库岸边坡的形变趋势与库水位及土壤含水量后向散射系数变化有着明显的相关性,水库蓄水是致使边坡体加速沉降的主要因素。

西藏DG水电站大坝安全监测系统设计

基于相关规程规范和已建工程经验,结合西藏DG水电站坝址区水文地质条件、枢纽工程的布置及各建筑物结构形式,各项安全监测设施的特点,研究建立了大坝自动化安全监测系统。电站下闸蓄水至今,大坝安全监测系统运行正常,变形、位移、渗流等实测资料、现场巡查及相关复核计算成果表明,大坝工作性态正常,满足设计和相应规程规范等要求,自动化安全监测系统可供类似工程设计参考。

水电站门式启闭机电气控制系统升级改造技术的应用

为改善水电站门式启闭机电气控制系统工作性能,对一种水电站门式启闭机电气控制系统升级改造技术的技术方案及施工措施进行介绍,为该技术在水电站门式启闭机上的应用提供了实践经验。某项目水电站门式启闭机电气控制系统升级改造方案采用基于PROFINET通讯技术的PLC控制系统,可有效避免信号干扰导致的设备停机以及设备误操作引起的安全事故;同时增设安全监控管理系统,使运行状态和故障信息有据可查。

梯级水电站防汛和应急管理的研究与应用

岷江流域和渔子溪支流常年遭受自然灾害的侵袭,暴雨、泥石流以及山体滑坡、道路坍塌等次生灾害严重影响水电站的安全稳定运营。通过流域内梯级水电站防汛和应急管理的研究,以“四个打破,一个突出”为核心,建立梯级水电站多维度防汛和应急联动管理机制,确保水电站在遇到设计标准内的洪水时,不垮坝、不漫坝、不水淹厂房;遇到超标洪水等特殊情况下,相应的应急措施有效、可靠,以降低水电站的损失。

浅析岩滩水电站防洪调度措施及效果

笔者结合岩滩水电站的防洪能力,分析制约岩滩水库行洪的外部因素,提出水情气象预报、编制防洪风险图、汛期水位动态控制、洪前预泄、流域梯级水库群优化运行等提升防洪能力的调度措施。结果表明,所采取的调度措施是有效的,能够最大发挥岩滩水电站工程资源效益,取得巨大的经济效益。

基于BP神经网络的油气田站场管道安全预警方法

油气田站场管道承担着接收、增压、分输、清管、计量等具有高度危险性工作,一旦管道出现异常状况容易引起重大燃烧和爆炸事故,因此对油气田站场管道状态进行监测及安全预警十分重要。利用基于BP神经网络的状态监测数据处理方法,首先确定油气田站场管道应变数据作为状态监测指标,采集油气田站场管道的应变监测数据,通过BP神经网络进行仿真实验,获得并验证管道应变预测模型,利用控制图理论筛选出异常数据并对异常数据分类分级,同时依据危险等级类别进行安全预警并制定预案。该方法在风险发生初期就能发现异常状态数据,从而有针对性地采取相应的安全对策,以防止危险事故的发生。