【作者】 吴吉民；

【导师】 许模；

【作者基本信息】 成都理工大学 ， 地质工程， 2009， 硕士

【摘要】 水库在蓄水过程中及运行后,破坏了库岸斜坡原有的自然平衡条件,引起坡体形状及稳定性的变化,导致库岸产生坍塌、崩塌及滑坡等地质灾害。水库形成以后,沿岸地区地质环境条件将发生显著变化,同时由于库水位升高造成河流局部侵蚀基准和地下水位抬高,并引起水位动态变化,使水库岸坡遭受强烈改造。水库库岸失稳是水利水电工程中常见的斜坡变形方式。乌东德水电站是金沙江下游河段四个水电梯级的第一级,装机容量870万kw。按正常蓄水位975m、坝高265m初选方案,库尾在攀枝花市区以东密地村一带,干流库长206.7km。本文在现场翔实查明库区地质环境条件的基础上,划分库区岸坡结构类型并分段,分析岸坡变形破坏现象(滑坡、崩塌及危岩发育分布规律),研究岸坡变形破坏模式及其诱发因素,并进行滑坡、危岩及崩塌稳定性及岸坡稳定性评价,最终进行库岸分段稳定性评价,提出库岸失稳防治对策。论文主要结论如下:(1)研究区库岸左右两岸干流总长195.4km,其中:土质岸坡长49.3km,占干流库岸干流总长的25.23%;浅变质岩岸坡长41.3km,占干流库岸总长的21.14%;碳酸盐岩岸坡长14.7km,占干流库岸总长的7.52%;碎屑岩岸坡长90.1km,占干流库岸总长的46.11%。三条主要支流库岸总长27.5km,全属碎屑岩岸坡。(2)库区岸坡结构类型可分段为:土质岸坡25段(滑坡堆积土质岸坡4段、崩坡积土质岸坡11段、冲洪积土质岸坡10段);浅变质岩岸坡12段(顺向中倾浅变质岩岸坡9段、逆向中倾浅变质岩岸坡3段);碳酸盐岩岸坡5段(顺向缓倾碳酸盐岩岸坡3段、逆向缓倾碳酸盐岩岸坡1段、逆向中倾碳酸盐岩岸坡1段);碎屑岩岸坡20段(顺向缓倾碎屑岩岸坡5段、逆向缓倾碎屑岩岸坡14段、斜向缓倾碎屑岩岸坡1段)。(3)库区库岸斜坡变形破坏现象主要为滑坡、崩塌及危岩体,其中:滑坡32处(特大型滑坡占37.5%;大型滑坡占40.6%;中型滑坡21.9%),崩塌及危岩体18处(规模均达到中型以上,大型和特大型占89%)。(4)库区土质岸坡岸坡破坏再造类型主要有冲蚀-磨蚀型、坍塌后退型、整体滑移型三种。(5)库区岩质岸坡变形破坏模式主要可分为四种:缓倾层状岩质岸坡滑移-拉裂-剪断―三段式‖;顺向中倾层状岩质岸坡顺层的蠕滑拉裂式滑动或平面滑移模式;沿层间软弱层夹层的―滑移(弯曲)-剪断‖模式或―滑移-剪断‖模式;逆向中倾层状岩质岸坡―弯曲-倾倒‖模式;斜向层状岩质岸坡相对稳定,受浅层裂隙影响,变形破坏模式主要表现为局部或小规模的崩塌、滑坡等。(6)降雨、河流侵蚀作用及人类工程活动影响为库区岸坡变形破坏的三大主要诱发因素。(7)库区32处滑坡中,现状条件下,基本稳定19处,稳定性较差6处,稳定性差7处;蓄水后,基本稳定14处,稳定性较差7处,稳定性差11处。库区18处崩塌及危岩体中,现状条件下,危岩体基本稳定10处,稳定性较差7处,稳定性差1处,崩塌基本稳定9处,稳定性较差5处;蓄水后,危岩体均位于蓄水位以上,其稳定性基本不受影响,危岩体下部部分位于水位以下的崩塌体稳定性则有所降低。(8)从库区岸坡稳定性量化评价结果来看,岸坡稳定性较好(稳定、基本稳定)的段数占总段数的54.8%、总长度的83.3%,而稳定性差和较差的库段段数也较多,占总段数的45.28%、但只占总长度的26.7%。(9)根据乌东德库区库岸的实际情况,遵循―防治结合、防大治急、分期治理和因地制宜综合治理‖的三项原则,库岸失稳主要防治对策为:监测与预报、防止降水与地表水大量入渗、防止坡体后缘严重加载、防止河流侵蚀作用或前缘减载、综合治理,保护性开发土地资源。更多还原

【Abstract】 During the process of impounding and normal operation of the reservoir, the primary natural balance condition of bank slope is distoryed, which changes the shape and stability of the slope,and then causes the geo-disasters,such as collapse, landslip and land slide. After the reservoir comes into being, the geological condition along the bank will be changed evidently, at the same time, the rise of the water level of the reservoir causes the rise of the river’s partial corrasive datum plane and the water table, and the dynamic change of the water table, so the bank slope is reconstructed strongly. The unstabilization of bank is one of the slope’s normal deformation modes in hydrodynamic engineerings.Wudongde hydrodynamic power station is the first one of the four hydrodynamic step along the downriver reach of the Jinshajiang River,whose capacity is 8.7 million kilowatt. According to the earlier blue print that the normal water level is 975m and the height of dam is 265m, its rear is near to Midi village, located on the east to Panzhihua city, and its trunk is up to 206.7 kilometers long.On the basis of the investigation of the geological condition of the reservoir area,this thesis partitions the structure style of bank slope and separates the bank from them , analyses the phenomena of deformation and breakage( the disciplinarian on the development and distributing of landslide, landslip and crag), studies the mode and inducement of the deformation and breakage about the bank slope, and evaluates the stability of landslide, landslip and crag & bank slope. At last, it evaluates the stability of the bank in segments and takes measures against the unstability of the bank. The main conclusion is as the following: (1) The left and right bank of the trunk in research area is 195.4 kilometers long. in which the length of soil bank is 49.3 kilometers (25.23 percent ), feeble- metamorphosed rock bank is 41.3 kilometers (21.14 percent ), carbonate rock bank is 14.7 kilometers (7.52 percent ), clastic rock bank is 90.1 kilometers (46.11 percent ). The bank of the three main anabranch is 27.5 kilometers long ,which are all clastic rock bank.(2) The structure types of bank slope in the reservoir area can be divided into many segments: soil bank 25 segments (coasting deposit: 4 segments, colluvial deposit: 11 segments, accretion: 10 segments ); feeble- metamorphosed rock bank 12 segments(direct-dipmiddling-obliquitystrata: 9 segments,anti-dip middling-obliquity:3 segments); carbonate rock bank 5 segments (direct-dip mild-obliquity strata: 3 segments, anti-dip mild-obliquity: 1 segment, anti-dip middling-obliquity: 1 segment); clastic rock bank 20 segments (direct-dip mild-obliquity strata: 5 segments, anti-dip mild-obliquity: 14 segments, transverse-dip mild-obliquity: 1 segment).(3) The phenomena of the deformation and breakage about the bank slope in the reservoir area mainly includes: langslide, landslip and crag, in which there are 32 langslides(the over-scale: 37.5 percent; the good-scale: 40.6 percent; the medium-scale: 21.9 percent ),18 landslips and crags (all exceeding the medium-scale, the over-scale and the good-scale: 89 percent).(4) The breakage and reconstruct of soil bank slope in reservoir area is mainly he models of erosion-ablation, recessional collapse and holistic slipping.(5) The types and the modes of deformation and breakage about the rock bank slope can be divided into four styles in the reservoir area:The―three sections‖of sliding - tension cracking - shearing model in mild-obliquity strata; the creep-tension cracking or consequent sliding model; the creep (bending)-shearing or sliding-shearing model by interbedded soft zone in direct-dip middling-obliquity strata; the bending - toppling model in anti-dip middling-obliquity strata.They are stable relatively in transverse-dip strata, influenced by superficial cranny, whose deformation and breakage model usually is partial and small-scale landslides and landslips,etc.(6) Rainfall, corrosion and anthropic engineering activity are the three main inducement of the deformation and breakage about the bank slope in the reservoir area.(7) The evaluation of the stabilization of 32 langslides is as the following: In current conditions, there are 19 rather stable one, 6 rather unstable one and 7 unstable one; After impounding, there are 14 rather stable one, 6 rather unstable one and 11 unstable one.The evaluation of the stabilization of 18 landslips and crags is as the following: In current conditions, there are 10 rather stable one, 7 rather unstable one and 1 unstable one; After impounding, the stabilization of the crags will not be changed, the stabilization of some landslips will be depressed, which will be under the water level.(8) Based on the quantitated result of the stabilization of the bank slope in the reservoir area, the good-stabilization bank slope is 54.8 percent of the total segments and 83.3 percent of the total length, the not-good-stabilization bank slope is 45.28 percent of the total segments ,but only 26.7 percent of the total length.(9) Based on the actual condition of the bank slope in the reservoir area, it takes the meatures to prevent the bank slope off its unstability: inspecting and forecasting, preventing rainfall and surface water from infiltrating, preventing the backyard of the slope from loading severly, preventing the frontage of the slope from corroding and unloading, comprehensive treating, exploiting land resources protectly and so on.更多还原