陈村大坝基础断层处理效果监测研究

陈村大坝坝基地质条件复杂，本文简述Ｆ１１、Ｆ３１、Ｆ３２、Ｆ３５四条大断层的危害及处理过程依据测缝 针、倒垂线，扬压力和渗漏量等监测设施所获取的大量信息，对处理措施的效果，进行反馈研究。     

Predicting dam failure risk for sustainable flood retention basins: A generic case study for the wider Greater Manchester area

This study aims to provide a rapid screening tool for assessment of sustainable flood retention basins (SFRBs) to predict corresponding dam failure risks. A rapid expert-based assessment method for dam failure of SFRB supported by an artificial neural network (ANN) model has been presented. Flood storage was assessed for 110 SFRB and the corresponding Dam Failure Risk was evaluated for all dams across the wider Greater Manchester study area. The results show that Dam Failure Risk can be estimated by using the variables Dam Height, Dam Length, Maximum Flood Water Volume, Flood Water Surface Area, Mean Annual Rainfall (based on Met Office data), Altitude, Catchment Size, Urban Catchment Proportion, Forest Catchment Proportion and Managed Maximum Flood Water Volume. A cross-validation R² value of 0.70 for the ANN model signifies that the tool is likely to predict variables well for new data sets. Traditionally, dams are considered safe because they have been built according to high technical standards. However, many dams that were constructed decades ago do not meet the current state-of-the-art dam design guidelines. Spatial distribution maps show that dam failure risks of SFRB located near cities are higher than those situated in rural locations. The proposed tool could be used as an early warning system in times of heavy rainfall.     

尾矿坝坝基管涌砂槽模型试验研究

以沈阳浑南矿业公司的尾矿砂作为物料,针对尾矿坝堤基进行了管涌机理的砂槽模型试验研究,观察并分析了管涌发生、发展并导致溃堤的机理和过程。试验结果表明,管涌破坏发生在弱透水层的顶部,低于临界水头时,管涌仅在一定范围内发展并最终停止,管涌通道不会与江河水连通,一旦超过临界水头,管涌通道持续发展并最终与江河水连通,连通管流的强力冲刷最终导致堤基整体破坏和溃堤。同时,在坝基厚度改变情况下,分别探索了渗流量、砂环直径、测压管水头、管涌破坏时间等的变化规律。     

大坝变形预测的支持向量机模型

支持向量机在解决非线性及高维模式识别问题中表现出其特有的优势。针对大坝变形具有强非线性的特点以及传统神经网络模型预测时存在局部极小与过学习等问题,将支持向量机应用于大坝变形预测。以某大坝的变形监测数据为例,建立SVM预测模型,将支持向量机模型与神经网络模型进行比较分析。结果表明,该模型具有较高的精度,可以很好地应用于大坝变形监测分析。     

黄河三门峡大坝工程现实风险规避刍议

After three ups and downs during the planning and designing stage, the project of the Yellow River Sanmenxia Dam finally completed in 1960. After two times reconstructions and three times change of its operation mode, the dam realizes the working mode of “storing clear water and draining sand-containing water”. On the basis of the lessons learned from the Dam, the paper proposes the idea that an unique ecosystem and living environment have been formed in the middle and lower valley of Yellow River. Sanmenxia dam cannot be abandoned or blowed up. To construct an ecological system in Yellow River is an effective measure to avoid the risk of Sanmenxia Dam.     

东北某水库坝基岩体质量分级研究

应用单因素和多因素分类方法,对东北某水库坝基岩体质量进行了分级研究.研究结果表明,除新鲜岩体和微风化岩体外,该区弱风化岩体为良质岩体,经适当处理后,可以考虑作为该水库坝基岩体;而对小部分的弱风化镶嵌结构的岩体,性质较差,需要挖除.     

水布垭枢纽地质研究与实践

水布垭水电站工程有两个第一:一个世界第一,是目前世界最高面板堆石坝(坝高233 m);一个国内第一,是国内在强岩溶化地区建设的抬高水头最高(203 m)的大坝.水布垭坝址岩层缓倾上游,建坝岩体软硬相间,分布有多层剪切带和缓倾角断层,还有煤系地层平卧于河床坝基下,这样的坝基岩体决定了不能兴建混凝土高坝.坝址区天然建筑材料丰富,当地材料坝对岩体要求较低,其中混凝土面板堆石坝不仅对岩体条件要求较低,且具有稳定性好,适应性强,建设速度快,总体安全程度较高等综合优点,作为选定坝型.勘察期间针对坝址地质条件进行了广泛的研究与论证,坝址存在3大主要地质问题:①环境地质问题,坝前库首地段分布有18个总量近1亿m3的滑坡与危岩体,坝下游泄洪雾雨区还分布有14个规模不等的滑坡、变形体和土体斜坡等,还有一个相对比高达360 m、具不利地质结构(上硬下软)的马崖高边坡;②坝址防渗问题,峡谷两岸岩溶强烈发育,勘察期和施工期实际揭示的岩溶洞穴之多就像筛子一样,清江枯水位197 m高程,大坝正常蓄水位400 m高程,坝前抬高水头203 m,解决岩溶绕坝渗漏问题是枢纽工程能否成立的关键技术问题之一;③软岩成洞问题,这里地下洞室较多、岩体条件很差,特别是在地下厂房的中下部,软岩相对集中,垂直开挖形成地下厂房,成洞问题难度很大,在工程建设中,采取了一系列有效措施,以适应这一复杂的地质条件并取得了成功.     

水布垭水电站防淘墙设计与施工

水布垭水电站溢洪道采用挑流消能,其最大下泄流量18 280 m^3/s,泄洪落差171 m,泄洪功率31 000 MW。消能冲刷区环境地质复杂,岩性软弱,断裂构造发育,抗冲刷能力低。消能冲刷区采用两岸设置防淘墙而不护底的防护方案。防淘墙结构采取了预应力锚索、锚喷支护和排水等保护措施。采用分层钻爆逆作法结合宽竖井施工法,施工方法简单、稳定可靠、工程造价低,满足设计要求。     

水布垭水电站帷幕灌浆优化

水布垭水利枢纽位于岩溶化程度较高的石灰岩地区,设计帷幕工程量大,施工工期长,若能对帷幕进行适当优化,对节省工程投资和保证工期都有十分重要的意义。为此,介绍了水布垭工程利用前期大量地质勘探成果,分析了坝区岩体渗透特征,从防渗范围、灌浆孔布置等方面对防渗帷幕进行了优化。最终实现比施工图减少约5万m灌浆进尺的成果,取得了较好的经济效益。     

光纤陀螺系统在水布垭工程中的应用

针对堆石体沉降和面板挠度的传统监测仪器对高面板堆石坝监测的局限性,提出了高面板堆石坝监测仪器革新的迫切需要,通过介绍光纤陀螺系统的监测原理和在水布垭工程的实践结果,说明了光纤陀螺监测系统在高面板堆石坝应用的可行性,为面板堆石坝堆石体沉降和面板挠度监测开拓了新的思路。