發(fā)布時(shí)間：2018-03-21 22:29

  本文選題：降雨入滲　切入點(diǎn)：山泉滑坡　出處：《成都理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：降雨是導(dǎo)致滑坡失穩(wěn)的主要原因之一。降雨入滲會(huì)增大滑坡巖土體的重度,還會(huì)使滑坡體內(nèi)水位抬升,增加飽和區(qū)孔隙水壓力,降低非飽和區(qū)基質(zhì)吸力,降低抗剪強(qiáng)度。因此,分析降雨入滲對山泉滑坡穩(wěn)定性的影響具有重要意義。本文采用現(xiàn)場地質(zhì)調(diào)查、定性分析與數(shù)值計(jì)算的方法,對不同降雨條件下山泉滑坡地下水流場變化進(jìn)行了研究,并在此基礎(chǔ)上,分析了降雨入滲對山泉滑坡穩(wěn)定性的影響。主要的研究工作及所取得的認(rèn)識如下:1.山泉滑坡平面形態(tài)呈掛鐘形態(tài),主滑方向145°,后緣寬度較大,向前緣方向?qū)挾葷u小。主滑方向最大縱長達(dá)310m,坡面平均長約280m,最大橫寬約330m,平均寬約260m,面積約0.0838Km2,平均厚度約9.5m,滑坡體規(guī)模80萬m3,為中型中層堆積層(土質(zhì))滑坡。2.山泉滑坡為典型的牽引式滑坡,其發(fā)生蠕滑變形的原因是前緣的人工開挖改變了原有的坡形條件,而降雨作用誘發(fā)了滑坡的變形破壞。3.研究了在不同降雨強(qiáng)度、不同降雨歷時(shí)及一次強(qiáng)降雨全過程三種降雨條件下,山泉滑坡地下水流場變化規(guī)律。在降雨的初始階段,雨水優(yōu)先向山泉滑坡坡腳方向滲透,水位首先在坡腳處抬升。而降雨結(jié)束后,山泉滑坡坡腳處水位下降會(huì)出現(xiàn)延后現(xiàn)象。降雨強(qiáng)度和降雨持續(xù)時(shí)間的增加,會(huì)導(dǎo)致山泉滑坡地下水位上升。一次強(qiáng)降雨停止后,山泉滑坡地下水位變化總體趨勢為:先下降較快,然后下降速率逐漸減緩。由于山泉滑坡下層碎塊石土較厚,且滲透性較好,因此地下水比較容易接受降雨入滲補(bǔ)給,在雨停后地下水位及時(shí)下降。沒有出現(xiàn)明顯的滯后現(xiàn)象。4.對不同降雨條件下山泉滑坡的穩(wěn)定性進(jìn)行計(jì)算分析,獲得了不同降雨條件下山泉滑坡的穩(wěn)定性變化規(guī)律。在降雨強(qiáng)度較小(≤20mm/d)且降雨時(shí)間較短時(shí),降雨對山泉滑坡穩(wěn)定性影響小,隨著降雨強(qiáng)度的增加,降雨對山泉滑坡穩(wěn)定性的影響變大。在相同降雨強(qiáng)度(30mm/d)下,隨著降雨持續(xù)時(shí)間的增長,山泉滑坡穩(wěn)定性快速下降。暴雨會(huì)使山泉滑坡的穩(wěn)定性下降到不穩(wěn)定狀態(tài)。雨停后,山泉滑坡穩(wěn)定性約在兩天時(shí)間內(nèi)回升到基本穩(wěn)定的狀態(tài)。在此之后,山泉滑坡穩(wěn)定性呈緩慢回升,逐漸趨于穩(wěn)定。山泉滑坡在天然狀態(tài)和較小的降雨強(qiáng)度(≤20mm/d)且降雨時(shí)間較短條件下,處于穩(wěn)定狀態(tài)。但在暴雨和持續(xù)的中等降雨強(qiáng)度條件下,山泉滑坡會(huì)進(jìn)入不穩(wěn)定狀態(tài)。
[Abstract]:Rainfall is one of the main causes of landslide instability. Rainfall infiltration will increase the severity of landslide rock and soil mass, raise the water level of landslide, increase pore water pressure in saturated area, reduce the suction of matrix in unsaturated area, and reduce shear strength. It is of great significance to analyze the influence of rainfall infiltration on the stability of mountain spring landslide. In this paper, the variation of groundwater flow field of mountain spring landslide under different rainfall conditions is studied by means of field geological investigation, qualitative analysis and numerical calculation. On this basis, the influence of rainfall infiltration on the stability of mountain spring landslide is analyzed. The main research work and the understanding obtained are as follows: 1. The plane shape of mountain spring landslide is in the form of wall clock, the main slide direction is 145 擄, and the width of the rear edge is large. The width of the front edge direction is smaller. The maximum longitudinal length of the main slip direction is 310 m, the average slope surface length is about 280 m, the maximum transverse width is about 330 m, the average width is about 260 m, the area is about 0.0838 km ~ 2, the average thickness is about 9.5 m, and the landslide body is 800000 m ~ 3 in size, which is a medium middle layer (soil) landslide. Shanquan landslide is a typical traction landslide, The reason of creep deformation is that the artificial excavation of the leading edge changes the original slope condition, and rainfall induces the deformation and failure of landslide. 3. The different rainfall intensity is studied. Under three kinds of rainfall conditions: different rainfall duration and one heavy rainfall, the groundwater flow field of Shanquan landslide changes. In the initial stage of rainfall, Rain Water preferentially penetrates to the foot of mountain spring landslide. The water level rises first at the foot of the slope. After the rainfall ends, the drop of the water level at the foot of the mountain spring landslide will be delayed. The increase in the intensity and duration of the rainfall will lead to the rise of the underground water level of the mountain spring landslide. After a strong rainfall has stopped, The general trend of groundwater level change in Shanquan landslide is that the groundwater level decreases rapidly and then slows down gradually. Because the debris and rock soil in the lower layer of Shanquan landslide is thicker and the permeability is better, it is easy for groundwater to accept rainfall infiltration and recharge. The groundwater level drops in time after the rain stops. There is no obvious lag phenomenon .4.The stability of the mountain spring landslide under different rainfall conditions is calculated and analyzed. When the rainfall intensity is less than 20 mm / d and the rainfall time is short, the influence of rainfall on the stability of mountain spring landslide is small, and with the increase of rainfall intensity, the stability of mountain spring landslide under different rainfall conditions is obtained. Under the same rainfall intensity (30 mm / d), with the increase of rainfall duration, the stability of mountain spring landslide decreases rapidly. After the rain stops, the stability of mountain spring landslide decreases to an unstable state. The stability of the mountain spring landslide returned to a basically stable state in about two days. After that, the stability of the mountain spring landslide rose slowly. The landslide is in a stable state under the condition of natural condition and smaller rainfall intensity (鈮，

本文編號：1645867