發(fā)布時間：2018-11-24 10:37

【摘要】：針對周期性干濕循環(huán)作用下巖石損傷劣化問題,以三峽庫區(qū)某邊坡的中風化砂巖為研究對象,分別對不同干濕循環(huán)次數(shù)作用下"干燥"和"飽和"狀態(tài)的砂巖進行全斷面CT掃描試驗、巴西劈裂試驗、單軸和三軸壓縮試驗。試驗結果表明:在相同的干濕循環(huán)次數(shù)n下,"干燥"狀態(tài)下砂巖的宏細觀力學參數(shù)大于"飽和"狀態(tài)下的參數(shù);各典型區(qū)域的CT數(shù)均值隨著循環(huán)次數(shù)非線性累積增加,初期變化較快,當n≥3時,細觀損傷演化速度趨于緩慢;砂巖單軸抗壓強度、彈性模量、抗拉強度、黏聚力、內(nèi)摩擦角隨n的增加呈對數(shù)下降,泊松比隨n的增加而增大。干濕循環(huán)作用對砂巖不同力學參數(shù)的劣化程度不一,巖樣"抵抗拉伸性能"大于"抵抗壓縮性能"對水的敏感性�；谠囼灁�(shù)據(jù)擬合,對不同干濕循環(huán)作用下兩種含水狀態(tài)的砂巖M C屈服準則進行了修正,為工程中獲得任意圍壓下巖石的破壞強度提供了理論依據(jù)。
[Abstract]:Aiming at the problem of rock damage and deterioration under periodic dry-wet cycle, the middle weathered sandstone of a slope in the three Gorges reservoir area is taken as the research object. The full section CT scan test, Brazilian splitting test, uniaxial and triaxial compression test were carried out on the sandstone under different dry and wet cycles. The experimental results show that under the same dry-wet cycle times n, the macro and meso-mechanical parameters of sandstone in "dry" state are larger than those in "saturated" state. The mean value of CT number in each typical region increases with the nonlinear accumulation of cycle number and changes rapidly at the initial stage. When n 鈮，

本文編號：2353370