本文選題：垮山灣滑坡 + 滑坡分區(qū)　； 參考：《成都理工大學(xué)》2015年碩士論文

【摘要】：漂水巖水庫壩基開挖施工過程中,探明滑坡體坡腳恰好位于設(shè)計(jì)面板堆石壩壩肩部位,而開挖前在庫岸區(qū)內(nèi)未見該滑坡體明顯的滑動(dòng)跡象�；碌匦蔚孛草^平緩,且?guī)r層傾角較緩,地表裂縫不甚發(fā)育而易被忽視。坡體由還建公路向河床逐級(jí)開挖過程中,坡體前緣出現(xiàn)的變形愈加明顯。若對滑坡采取的防治處理措施不足,在將來可能影響壩體穩(wěn)定,輕則導(dǎo)致庫容減小,重則壩體失穩(wěn)。為保障壩體的穩(wěn)定和水庫的正常運(yùn)行,本文立足于區(qū)域及工程區(qū)基本地質(zhì)條件,從滑坡變形特征、變形監(jiān)測數(shù)據(jù)、巖土體物理力學(xué)性質(zhì)出發(fā),結(jié)合過程機(jī)制分析法、理論計(jì)算法及UDEC、FLAC3D、Geostudio等數(shù)值模擬手段分析研究滑坡形成機(jī)制、前緣局部變形破壞機(jī)制以及滑坡在前緣開挖臨空后、筑壩回填、降雨及庫水位升降等工況下的整體及局部穩(wěn)定性和應(yīng)力應(yīng)變的變化特征,主要取得了以下成果及認(rèn)識(shí):(1)滑坡體最大厚度約30m,方量約250×104m3,屬大型滑坡。據(jù)滑坡變形特點(diǎn)與工程建筑物、邊坡開挖等的關(guān)系,將滑坡分為I1變形破壞亞區(qū)、I2變形亞區(qū)和下游側(cè)II相對穩(wěn)定區(qū)。其中I1區(qū)方量達(dá)35×104m3,前緣局部坍塌,暴雨時(shí)趾板有水滲出;滑坡I2區(qū)開挖前后坡體無明顯變形,相對I1區(qū)穩(wěn)定;II區(qū)較穩(wěn)定,無明顯變形。據(jù)現(xiàn)場地質(zhì)踏勘及滑坡前緣開挖揭露,“似層狀”巖層在坡體中十分發(fā)育,采用鉆探、鉆孔電視手段及現(xiàn)場物理力學(xué)試驗(yàn),探明坡體多處軟弱夾層、擠壓帶發(fā)育且存在架空現(xiàn)象。上游邊界拉裂縫及后緣拉陷槽發(fā)育,坡腳開挖揭露剪出口,暴雨后坡體有多處滲水口,河床未開挖前滑帶隱藏。(2)滑坡體原為志留系軟硬互層狀巖體,緩傾坡外,層間錯(cuò)動(dòng)帶或軟弱夾層較發(fā)育。滑坡形成歷史分析表明滑坡主要經(jīng)歷了河谷下切和坡體蠕滑、壓致拉裂面由下至上延伸、斜坡順層滑動(dòng)和河床再造四個(gè)演變階段。UDEC數(shù)值模擬再現(xiàn)了滑坡早期在自重作用下沿下伏軟弱結(jié)構(gòu)面、軟弱夾層變形破壞的過程。據(jù)坡體后緣拉陷槽和陡傾結(jié)構(gòu)面特征、坡體開挖揭露的坡體結(jié)構(gòu)及拉張裂隙和“階狀”裂隙等變形特征、數(shù)值模擬結(jié)果,綜合判定滑坡變形破壞模式為“滑移—壓致拉裂”。(3)監(jiān)測數(shù)據(jù)顯示,開挖使I1區(qū)變形,隨著開挖深度的增大變形逐漸加劇,暴雨條件下局部坡體發(fā)生垮塌�；聟^(qū)位于向斜核部向兩翼轉(zhuǎn)折部位,坡體后緣、下游側(cè)陡傾結(jié)構(gòu)面發(fā)育,為開挖條件下滑坡前緣I1區(qū)的局部變形破壞提供了構(gòu)造條件。對I1區(qū)逐級(jí)開挖過程的現(xiàn)場勘察、監(jiān)測、FLAC3D數(shù)值模擬表明:坡體在前緣臨空、內(nèi)部殘留的軟弱夾層及軟弱結(jié)構(gòu)面泥化、軟化作用的共同影響下局部貫通,上部坡體發(fā)生拉裂,該區(qū)在降雨或施工水流作用下發(fā)生“蠕滑—拉裂”變形,具牽引式特征,對降雨等水的作用較敏感。(4)采用極限平衡法對滑坡穩(wěn)定性分析表明:滑坡整體在各工況條件下處于基本穩(wěn)定~穩(wěn)定狀態(tài),滑坡II區(qū)穩(wěn)定性較高,I1區(qū)穩(wěn)定性低于其他分區(qū)。結(jié)合SEEP/W與SLOP/W對滑坡滲流場及穩(wěn)定性進(jìn)行研究,滑坡在降雨時(shí)前緣I1區(qū)近坡表部位水位抬升稍高于坡體內(nèi)部,庫水位升降條件下坡體內(nèi)部浸潤線“滯后”于前緣坡腳處浸潤線的變化�；抡w穩(wěn)定性受開挖、筑壩回填、降雨及蓄水等影響稍小,處于基本穩(wěn)定~穩(wěn)定狀態(tài);滑坡I1區(qū)穩(wěn)定性受各工況影響較大,處于不穩(wěn)定~欠穩(wěn)定狀態(tài)。降雨、庫水升降對滑坡I1區(qū)穩(wěn)定性影響大。(5)采用有限元軟件Geostudio中SEEP/W與SIGMA/W模塊對各工況下坡體滲流場、應(yīng)力場耦合分析,發(fā)現(xiàn)與天然狀態(tài)相比,在滑坡前緣開挖后、筑壩回填以及庫水位升降條件下坡體剪應(yīng)力主要集中在I1區(qū)下部,坡腳趾板、462m馬道部位水平方向位移最為顯著。
[Abstract]:During the construction process of the dam foundation excavation of the bleeyan reservoir, it is proved that the foot of the landslide body is just located at the part of the dam shoulder of the design face rockfill dam, and there is no obvious sign of slide in the bank area before the excavation. The landform of the landslide is relatively gentle, and the dip angle of the rock layer is slow, and the surface cracks are not very well developed and easily ignored. In the process of progressive excavation, the deformation of the front edge of the slope becomes more and more obvious. If the prevention and treatment measures for the landslide are insufficient, it may affect the stability of the dam in the future, the light result in the decrease of the capacity of the reservoir and the instability of the dam body. In order to ensure the stability of the dam body and the normal operation of the reservoir, this paper stands in the basic geological conditions of the region and the engineering area, and changes from the landslide to the landslide. The form characteristics, deformation monitoring data, physical and mechanical properties of rock and soil, process mechanism analysis method, theoretical calculation method and UDEC, FLAC3D, Geostudio and other numerical simulation methods are used to analyze the mechanism of landslide formation, the mechanism of local deformation and failure of the front edge, and the backfilling of the dam, the rainfall and the rise and fall of the reservoir water level after the front edge of the excavation. The following achievements and understanding are obtained: (1) the maximum thickness of the landslide body is about 30m and the square amount is about 250 x 104m3, which is a large landslide. According to the relationship between the landslide deformation characteristics and the engineering buildings and the slope excavation, the landslide is divided into the I1 deformation subregion, the I2 deformation subregion and the downstream side II relative. In the stable area, the square of I1 area is 35 x 104m3, the front edge is partially collapsed, and the toe plate has water exudation when the rainstorm is torrential. There is no obvious deformation in the slope body before and after the excavation of the landslide I2 area, and the relative I1 area is stable. The II area is more stable and has no obvious deformation. According to the site geological exploration and the excavation of the landslide front, the "like layer" rock is very well developed in the slope body, using drilling and drilling electricity. According to the method and field physical and mechanical test, it is found that many weak interbeds in the slope, the extruding zone is developed and there are aerial phenomena. The upstream boundary pull cracks and the trailing edge trench grooves are developed, the slope foot excavation exposes the shear exit. The slope body has many seepage ports and the river bed before the excavation is excavated. (2) the landslide body is the Silurian soft and hard interbedded rock mass, gently tilting. The historical analysis of landslide formation shows that the landslide mainly experienced the downfall of the valley and the creep of the slope, the extension of the crack surface from the bottom to the top, the four stages of the.UDEC numerical simulation of the slope slide and the river bed reengineering. The deformation and failure process of the interlayer. According to the characteristics of the subsidence trough and the steep structure surface of the rear edge of the slope, the deformation characteristics of the slope body, such as the structure of the slope body and the tension fracture and the "order" fissure, are revealed. The numerical simulation results show that the deformation and failure mode of the landslide is "sliding compression cracking". (3) the monitoring data shows that the excavation makes the deformation of the I1 region deformed. The deformation of the excavation depth increases gradually, and the local slope collapse under the condition of heavy rain. The landslide area is located at the turning part of the two wings at the syncline core, the rear edge of the slope body and the steep slope of the downstream side are developed, which provides a structural strip for the local deformation and failure in the I1 area of the front edge of the landslide under the condition of excavation. The FLAC3D numerical simulation shows that the slope body is on the front edge, the internal residual weak intercalation and the weak structural surface are muddy, and the softening effect is affected by the joint under the influence of softening, and the upper slope is cracked. In this area, the deformation of "creep and crack" occurs under the action of rainfall or construction flow, which has the characteristic of traction and is more sensitive to rainfall and water. (4) The stability analysis by the limit equilibrium method shows that the landslide is stable in the basic stable state under all working conditions, the stability of the landslide II zone is higher and the stability of the I1 region is lower than that of other areas. The seepage field and stability of the landslide are studied with SEEP/W and SLOP/W, and the water level of the near slope at the front edge of the front edge of the front edge of the landslide is raised by the landslide. Slightly higher than the interior of the slope body, the infiltration line inside the slope body is lagging behind the change of the infiltration line at the foot of the front slope. The overall stability of the landslide is excavated, the dam is filled, the rainfall and the water storage are slightly affected, and the stability is in the basic stable state. The stability of the landslide I1 area is greatly influenced by various working conditions, and it is in the unstable under stable state. Rainfall, reservoir water lifts have great influence on the stability of the landslide I1 area. (5) using the finite element software Geostudio SEEP/W and SIGMA/W module to analyze the seepage field of the slope body and the stress field coupling analysis of each working condition, it is found that, compared with the natural state, after the excavation of the front edge of the landslide, the shear stress of the dam is mainly concentrated under the I1 area. The horizontal displacement of the 462m toe road is the most significant.
【學(xué)位授予單位】：成都理工大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P642.22

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本文編號(hào)：1910042