【摘要】：針對(duì)周期性干濕循環(huán)作用下巖石損傷劣化問(wèn)題,以三峽庫(kù)區(qū)某邊坡的中風(fēng)化砂巖為研究對(duì)象,分別對(duì)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(jìn)行全斷面CT掃描試驗(yàn)、巴西劈裂試驗(yàn)、單軸和三軸壓縮試驗(yàn)。試驗(yàn)結(jié)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(xì)觀力學(xué)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(dāng)n≥3時(shí),細(xì)觀損傷演化速度趨于緩慢;砂巖單軸抗壓強(qiáng)度、彈性模量、抗拉強(qiáng)度、黏聚力、內(nèi)摩擦角隨n的增加呈對(duì)數(shù)下降,泊松比隨n的增加而增大。干濕循環(huán)作用對(duì)砂巖不同力學(xué)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(duì)水的敏感性�；谠囼�(yàn)數(shù)據(jù)擬合,對(duì)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(zhǔn)則進(jìn)行了修正,為工程中獲得任意圍壓下巖石的破壞強(qiáng)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，

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