發(fā)布時間：2018-10-11 08:25

【摘要】：通過新型低溫動三軸儀的等幅循環(huán)荷載試驗,以更為符合客觀實際的圍壓、動應(yīng)力幅值以及固結(jié)和凍結(jié)方式,研究了凍土凍結(jié)期的殘余應(yīng)變規(guī)律,包括了溫度、荷載作用大小和次數(shù)對凍土的殘余應(yīng)變的影響。結(jié)果表明:凍土的殘余應(yīng)變隨著荷載振動次數(shù)的增加不斷增長,隨著溫度的降低不斷減少;凍土的殘余應(yīng)變增長模式表現(xiàn)為開始階段殘余應(yīng)變增長較快,后逐步緩慢增長,當(dāng)動應(yīng)力超過臨界破壞應(yīng)力之后,土試樣殘余應(yīng)變迅速增長并達(dá)到破壞;低溫凍土破壞應(yīng)力較常溫較大提高,低溫-5℃提高了20%~25%,低溫-10℃提高了45%~50%;凍土大多數(shù)荷載情況下處于非破壞狀態(tài),在一定次數(shù)荷載作用后,不同溫度土的殘余應(yīng)變發(fā)展近似平行狀態(tài),大動應(yīng)力幅值下的土試樣的殘余應(yīng)變對溫度更敏感。試驗設(shè)計克服了以往試驗過大固結(jié)應(yīng)力和過大動應(yīng)力的缺欠,得到的結(jié)果應(yīng)符合客觀實際。
[Abstract]:Through the constant amplitude cyclic load test of a new low temperature dynamic triaxial instrument, the residual strain law of frozen soil during freezing period, including temperature, is studied in order to conform to the objective reality of confining pressure, dynamic stress amplitude and consolidation and freezing mode. The influence of the magnitude and number of loads on the residual strain of frozen soil. The results show that the residual strain of frozen soil increases continuously with the increase of load vibration times and decreases with the decrease of temperature, and the residual strain growth pattern of frozen soil is that the residual strain increases rapidly at the beginning stage, and then slowly increases gradually. When the dynamic stress exceeds the critical failure stress, the residual strain of soil specimen increases rapidly and reaches failure, and the failure stress of low temperature frozen soil is much higher than that of normal temperature. Low-temperature -5 鈩，

本文編號：2263507