【摘要】：三峽庫區(qū)許多古滑坡在重力等內(nèi)、外地質(zhì)營力作用下呈現(xiàn)出長期而緩慢的變形特征,具有明顯的蠕變屬性。復(fù)活型古滑坡的滑帶常處于殘余強(qiáng)度狀態(tài),其運(yùn)動特征主要受滑帶土力學(xué)性質(zhì)和應(yīng)力狀態(tài)控制,研究原狀滑帶土在殘余強(qiáng)度狀態(tài)下的蠕變特性,對于了解復(fù)活型古滑坡滑動機(jī)制及預(yù)測其運(yùn)動趨勢具有重要意義。針對三峽庫區(qū)黃土坡滑坡原狀滑帶土開展環(huán)剪試驗(yàn),研究了不同應(yīng)力水平條件下滑帶土在殘余強(qiáng)度狀態(tài)下的蠕變變形規(guī)律。結(jié)果表明,滑帶土的蠕變速率與剪切應(yīng)力比R_(CSR)(蠕變剪切應(yīng)力與殘余強(qiáng)度的比值)呈正相關(guān)變化,當(dāng)R_(CSR)接近蠕變閾值1時,滑帶土等速蠕變明顯,部分試驗(yàn)條件下繼而發(fā)生加速蠕變,在相同R_(CSR)條件下,土樣法向應(yīng)力越大,其蠕變速率也越大。采用Burger模型對蠕變過程進(jìn)行模擬,獲取了模型的各參數(shù)。通過分析滑帶土等時蠕變曲線,獲得滑帶土長期抗剪強(qiáng)度約為0.95倍的殘余強(qiáng)度。此外,滑帶土蠕變速率受固結(jié)時間影響,蠕變速率隨固結(jié)時間增加而減小,滑帶土剪切強(qiáng)度隨著固結(jié)時間和剪切位移的增加可發(fā)生一定程度的恢復(fù)。
[Abstract]:Many ancient landslides in the three Gorges reservoir area show long-term and slow deformation characteristics under the action of gravity and external geological forces and have obvious creep properties. The slip zone of the resurrected ancient landslide is usually in the state of residual strength, and its motion characteristics are mainly controlled by the mechanical properties and stress state of the sliding zone soil. The creep characteristics of the undisturbed slip zone soil under the residual strength state are studied. It is of great significance to understand the sliding mechanism and predict the movement trend of the resurrected paleo-landslide. The cyclic shear tests were carried out on the loess slope landslide in the three Gorges Reservoir area, and the creep deformation of the slip zone soil under different stress levels was studied under the condition of residual strength. The results show that the creep rate of sliding zone soil is positively correlated with the ratio of shear stress to creep shear stress to the ratio of residual strength to creep shear stress. When (CSR) is close to the creep threshold 1, the constant velocity creep of sliding zone soil is obvious. Under some experimental conditions, accelerated creep occurs. Under the same R _ (CSR) condition, the higher the normal stress of soil sample is, the higher the creep rate is. The creep process is simulated by Burger model, and the parameters of the model are obtained. By analyzing the isochronous creep curve of sliding zone soil, the long-term shear strength of sliding zone soil is about 0.95 times. In addition, the creep rate of sliding zone soil is affected by consolidation time, and the creep rate decreases with the increase of consolidation time, and the shear strength of sliding zone soil can recover to some extent with the increase of consolidation time and shear displacement.
【作者單位】： 中國地質(zhì)大學(xué)教育部長江三峽庫區(qū)地質(zhì)災(zāi)害研究中心;中國科學(xué)院武漢巖土力學(xué)研究所;維也納農(nóng)業(yè)科技大學(xué)巖土工程研究所;武漢市測繪研究院;
【基金】：國家自然科學(xué)基金(No.41572286,No.41202199,No.41672297) 湖北省自然科學(xué)基金(No.2015CFB247) 中國博士后科學(xué)基金(No.2013M542098)~~
【分類號】：TU41

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