三峡永久船闸直立坡岩体变形监测与变形分析

众多不同类的监测仪器设备和长时间的观测资料,较全面地揭示了三峡永久船闸直立坡岩体的变形规律,在分析了大地测量点、滑动变形计、钻孔测斜仪和多点位移计的观测资料后,认为直立坡岩体整体稳定性良好.实测直立坡顶最大水平位移为32.72 mm;直立坡深层岩体的水平和竖向位移分布符合一般变形规律;统计模型分析表明,中隔墩侧直立坡岩体时效变形远小于边坡侧直立坡岩体;微新岩体上测点的时效变形小于强风化岩体上的测点.此外,北坡三闸首的观测成果说明,在槽挖结束后的第5个月开始浇筑混凝土是合理的.     

三峡工程高强锚杆施工工法

三峡永久船闸闸室采用世界先进的独特的混凝土薄壁衬砌墙结构型式,衬砌墙边坡稳定变形要求高,设计锚固荷载大.为有效地减少锚杆密度和钻孔直径,进而减少锚杆工程量,达到减轻因锚固施工而造成对直立岩体扰动伤害的目的,设计采用了高强锚杆将衬砌墙与岩体连接成整体,一方面锚固直立坡浅层岩体;另一方面连结闸室薄衬砌墙混凝土,有效地解决了混凝土衬砌墙自身稳定和船闸运行时期的边坡安全问题.     

三峡船闸高陡开挖边坡主要监测资料分析

通过对三峡船闸边坡形成后变形观测成果的系统分析,说明了边坡不同部位变形的收敛特点.分析表明,中隔墩和南、北直立坡顶的变形收敛很快,其上部大部分斜坡表面测点变形也在收敛,坡顶个别部位全强风化岩体上的测点收敛速度相对较慢,但对边坡稳定没有影响.     

数字正射影像在边坡治理中的应用

介绍了数字正射影像摄影在高陡边坡治理中的应用及主要技术问题.正射数字影像在边坡治理中的应用主要是找到结构面影像与真实岩体结构面空间展布、结构面的力学性状的关联.某电站长约200 m,高30～60 m的近直立边坡,由于公路开挖爆破及卸荷影响,部分结构面出现明显张裂,出现多处结构面不利组合,形成危岩体.通过数字正射影像技术的应用,确定了岩体不同区块的稳定性,并针对性地制定了处理方案.治理实例表明此种新方法快速、经济、实用,其它类似工程可以借鉴.     

三峡船闸高边坡锚固及新型无粘结锚索开发

三峡双线连续五级永久船闸，充分利用三峡花岗岩高强度的条件，闸室采用锚固于岩石直立边坡上的混凝土薄衬砌墙结构，使边坡岩体成为结构的组成部分，为提高边坡岩体的稳定性，共使用了229束1000kN和3975束3000kN的预应力锚索对边坡岩体进行加固，并安装了113台锚索测力计对锚索的受力状态进行监测，在使用锚索的数量及安装测力计台数上均属世界少有。三峡船闸高边坡预应力锚索的结构特点，施工工艺控制，加固效果分析及新型无粘结锚索试验研究与开发等锚固技术的应用成果具有推广价值。     

布鲁克柔性防护技术在大金坪水电站中的应用

松林河大金坪水电站厂房后山坡高差达114．5 m,从高程1 010．5-1125．0 m,坡面陡峭,边坡表层破碎带、夹层众多,岩体裂隙发育。厂房后山坡属于未经人工开挖的自然边坡,总体坡度较陡,平均坡度约70°,局部边坡近于直立。在暴雨、强振动等不良外力作用下,局部浅表层出现滑落、滚石。为保证边坡底部的厂房基础灌注桩施工不受高边坡施工的影响,在施工过程中采用了布鲁克主动防护网和被动防护网将坡面的破碎岩体网住,从而保证了高边坡施工与厂房基坑施工同时交叉进行,为实现厂房的发电目标发挥了巨大作用。     

快速编录技术在边坡治理中的应用

针对现场地质编录难度大、危险程度高、工作量大以及资料难以保存等问题，利用计算机技术开发了快速编录技术。该技术的开发为近直立高陡边坡结构面的分析提供了一种十分简便直观的工具，可以根据野外结构面精确的线路测量，通过窗口统计及结构面影像的室内统计分析，掌握边坡岩体结构面的发育组合规律，进而对边坡的稳定性做出客观正确的评价，方便设计人员拟定治理加固方案。将该技术应用到三峡库区某高切边坡加固治理中，取得较好的效果。     

乌东德水电站边坡岩体卸荷特征及稳定性评价

就水电工程而言,高陡边坡岩体卸荷可能导致边坡整体或局部失稳,对水电工程的施工及运行安全构成威胁。以乌东德水电站坝址区高陡岩质边坡为研究对象,在边坡卸荷岩体宏观地质特征、渗透特征及弹性波特征3方面研究的基础上,综合分析确定了坝址区边坡岩体卸荷的水平深度及特征,并就卸荷带岩体总体稳定性进行了分析评价。总体认为,乌东德水电站坝址区边坡岩体卸荷变形微弱,边坡总体稳定性较好。      

长河坝水电站枢纽区环境边坡勘察设计

结合环境边坡危岩体研究的最新科研成果,论述了长河坝水电站环境边坡的勘察、稳定性评价与防治方法,建立了长河坝水电站环境边坡危岩体稳定性评价标准,基于危害性的危岩体防治原则,为环境边坡危岩体的勘察与防治积累了宝贵的工程经验。     

三峡船闸高边坡设计实践中几个问题的再认识

根据前期设计论证,三峡船闸上部边坡开挖达到基本自稳,辅以排水及锚固,下部为直立坡与薄混凝土衬砌闸墙相结合.在施工过程中,遇到如何控制边坡开挖形态与闸室结构型式,中隔墩岩体保留与利用,坡面块体,排水隧洞的完整性,锚索的结构型式及钢绞线的强度利用系数等一系列问题.这些问题在施工过程中进行了分析.并通过动态设计方法,得到了较好的解决.     

渐扩综合式消力池尾坎高度和作用力的计算

研究了渐扩综合式消力池深度、坎高和尾坎作用力的计算方法。根据水跃方程、堰流理论和前人对渐扩式消力池水跃长度、共轭水深和淹没系数的研究成果,分析渐扩综合式消力池的设计方法,根据动量方程研究尾坎的作用力。给出了渐扩综合式消力池深度、坎高和尾坎作用力的计算公式和计算步骤。提出的坎高和作用力的公式不仅适用于渐扩综合式消力池的设计,也适用于渐扩消力坎式消力池,计算方法新颖,过程简单,精度满足设计需求。     

Laboratory Investigation of Stilling Basin Slope Effect on Bed Scour at Downstream of Stepped Spillway: Physical Modeling of Javeh RCC Dam

Stepped spillway and stilling basin are one of the most important energy dissipation structures. Eventhough, most of energy dissipated by these structures, but in skimming flow, the upstream flow motion is nonaerated and the residual energy capable to destroyed structures during floods. In this study, effect of stilling basin slope on bed scour, downstream of Javeh dam was investigating. Experiments performed in hydraulic structures laboratory of the University of Kerman with six different discharges (5, 7, 13, 17, 25 and 30 l/s.m) and five various stilling basin slope (0.02, 0.01, 0, ?0.01 and???0.02). The parameters such as maximum scour depth (d_s), flow velocity (in three point), water depth on upstream and downstream of stepped spillway and stilling basin, the distance of the maximum scour depth to sill (L_s) and the gheometery of scour hole measured. Result shown that when stilling basin slopes was 0.02, the average of maximum relative scour depth, 47% Increased and in ?0.02, 52.2% Decreased. In addition, the distance of maximum scour depth until stilling basin increased by increasing and decreased by decreasing the stilling basin slope.

     

乌江银盘水电站消力池及导墙脉动压力特性研究

依托乌江银盘水电站,对底流消能消力池底板及导墙脉动压力特性进行了较系统的水力学模型试验研究。通过大量点、面水流脉动荷载测试数据的综合分析,获得了消力池底板及导墙动水压力的分布规律。该研究丰富和发展了底流式消力池及导墙的脉动压力特性研究,可为对该类消能形式水流动力特性的深入研究提供科学参考。     

明渠梯形断面消力池池深和尾坎高度的计算方法

为研究明渠梯形断面消力池池深和尾坎高度的计算方法,依据前人对梯形断面消力池水跃共轭水深、梯形断面量水堰(槛)的研究成果,采用能量方程研究梯形断面挖深式消力池、消力坎式消力池和综合式消力池深度和坎高的计算方法。给出了梯形断面消力池池深、尾坎高度的计算公式,通过算例说明了计算过程。提出的消力池深度、坎高的计算公式可以作为梯形断面消力池设计的参考。     

隔河岩工程水力学安全监测技术及成果分析

 1998年汛期隔河岩水利枢纽观测部位为深孔、表孔 及消能工。其观测内容包括流态、时均压力、空化噪声、流速、雾雨。观测结果表明：该工程泄洪表孔、深孔、消力池及辅助消能工的各项水力学特性基本良好。泄水建筑物过流面、一级池两边岸坡均无蚀损，二级消能工上的消力墩、差动坎等均基本完好无损，但1998年2 月抽干检查发现消力池有局部磨损，左岸隔流堤护岸在1998年泄洪过程中发生局部坍滑。由于集中坝身泄洪，泄洪时雾化现象较严重，故须采取措施，以确保工程安全运行。将部分原 型观测资料与模型试验资料和计算值作了对比，总趋势和数值基本一致。     

跌坎消力池脉动压强试验

为了对跌坎消力池的水动力特性作更深入的研究,为跌坎消力池的设计防护提供参考,基于模型试验对跌坎消力池脉动压强的分布规律、幅值特性和频谱特性进行了系统研究。结果表明:水流条件是影响脉动压强的主要因素,跌坎消力池底板脉动压强系数沿程呈先增大后减小并逐渐趋于稳定的趋势;跌坎消力池底板中线和靠近边墙的脉动压强相当,脉动压强最大达到总水头的5.1%;跌坎消力池前端位于泄槽边墙延长线附近区域的脉动压强最大,最大达到总水头的11.5%;跌坎消力池前端中线的脉动压强比传统消力池有明显降低,最大降幅达55.2%。     

戽井同腔双漩滚消能池设计思路与应用

戽井同腔双漩滚消能池是在综合戽式消能池、冲击式消能池及消能井的结构特征与消能原理基础上提出来的.因消能池底有井,射流水体被架空,有下游井壁作为强迫水跃坎,迫使射流迸裂解体,于消能池内产生两个漩滚,致使水流在短距离内消耗大量动能.文中介绍其产生背景,结构体形设计思路、试验与应用前景.     

SUE水电站工程设计方案评价及优化

依据国际规范及合同要求,采用变态定床模型试验方法,对 SUE 水电站工程建筑物设计方案合理性进行评价。结果表明,SUE 水电站建筑物体型尺寸设计合理,泄洪闸过流能力满足要求,上游翼墙及下游导流墙起到导流、平稳流态的作用,但设计洪水流量时泄洪闸下游消力池消能防冲效果欠佳;为此,根据下游水跃的特点,合理加长消力池长度,并在消力池水跃尾部合适位置设置消力墩对原设计方案进行优化;优化后 PMF 洪峰流量时,海漫水流平稳,海漫末端断面垂向流速分布趋于正常流速分布;设计流量时,海漫下游底部流速减小,下游河床不会发生冲刷。     

Eco‐Friendly Countermeasures for Enlarged Basins Erosion

Eco‐friendly hydraulic structures (such as block ramps, rock weirs and stepped gabion weir) are generally made of rocks placed in two or more layers on a sloped bed. They are usually used in mountainous rivers to control sediment transport. The downstream stilling basin plays an important role in terms of both energy dissipation and erosion control. In addition, a correct design of the downstream stilling basin can create an optimal habitat for fish species in the river. Therefore, in the present work, an attempt was made to control the scour depth downstream of a block ramp using rock structures. In particular, the analysis was focused on scour characteristics in the presence of a protected and enlarged downstream channel. Namely, an abrupt symmetrically enlarged channel was simulated downstream of block ramps. Eco‐friendly protection structures, such as rock sills, were tested to limit the erosive process. Rock sills were placed transversally at different longitudinal and vertical positions in the stilling basin and scour morphology variations were investigated. Experiments were carried out for two different ratios of the width of the channel to the width of the ramp and three different ramp slopes. Several scour morphologies were distinguished and classified. In addition, empirical relationships were derived, by which it is possible to estimate the main scour geometry characteristics. Copyright © 2015 John Wiley & Sons, Ltd.     

Particle image velocimetry measurements of vortex structures in stilling basin of multi-horizontal submerged jets

Measurements of turbulent flow fields in a stilling basin of multi-horizontal submerged jets were made with the singlecamera Particle Image Velocimetry (PIV). The particle images were captured, processed, and subsequently used to characterize the flow in terms of the 2-D velocity and vorticity distributions. This study shows that the maximum close-to-bed velocity in the stilling basin is approximately reduced by 60%, comparing to the jet velocity at the outlet of orifices. The jet velocity is distributed evenly at the latter half of the stilling basin and the time-averaged velocity of the cross section is reduced by 77%-85%, comparing to the jet velocity at the outlet of orifices. These results show that the vortices with horizontal axes are continuously repeated during the form-merge-split-disappear process. The vertical vortices are continuously formed and disappeared, they appear randomly near the slab and intermittently reach the slab of the stilling basin. The range of these vortices is small. Vortices with horizontal axes and vertical vortices do not coincide in space and the vortices with horizontal axes only affect the position of the tail of the vertical vortices attached to the slab of the stilling basin.