等加载速率固结试验是在控制固结应力的施加速率为一常数条件下研究土体固结特性的试验方法。采用 GDS 高级固结仪, 开展了四种加载速率与瞬时加载的软土固结试验研究, 分析了土样的固结变形特性与孔隙水压 力变化规律。试验与分析结果表明, 加载速率越大土样固结速率越快, 土样完成固结所需的时间越短; 土体的最终 变形量由固结应力大小决定, 与加载速率无关; 随着固结应力施加速率的增加, 加载完成时土样的平均固结度呈下 降趋势; 加载速率越大, 土样底部的孔隙水压力上升速率越快, 孔隙水压力极值越大; 孔隙水压力在固结应力加载完 成前达到极值, 随后呈下降趋势, 有效应力迅速增加。

Consolidat ion test under constant lo ading rate is the test metho d for the co nso lidatio n process o f clay ey so il w ith a con2 stant rate o f contro l conso lidation str ess. Consolidat ion t ests with four different lo ading rates and instantaneo us lo ading wer e car ried out using the GDS advanced consolidat ion testing sy stem. The co nso lidatio n deformatio n character istics of soft clay and the chang e law of po re2w ater pressur e wer e analy zed. The findings indicated that ( 1) the faster of lo ading r ate, the larg er de2 fo rmation rate and the shorter time fo r consolidation o f soil sample; ( 2) the final defo rmation of soil sample is independent of the loading r ate but dependent o n the magnit ude o f co nso lidatio n str ess; ( 3) with the increasing o f loading r ate o f co nso lidatio n st ress, the averag e conso lidation deg ree of soil sample decr eases after loading ; ( 4) t he hig her the loading rate, t he faster the in2 cr easing rate o f por e pressure in the so il sample bo ttom and the lar ger t he ext reme v alue o f por e pressure; and( 5) the por e pres2 sure r eaches the max imum before the completion of loading of co nso lidatio n str ess, then decr eases w hile the effect ive str ess in2 cr eases rapidly.

水利部科技推广计划项目(T G1414) ; 水利部科技推广计划项目(1408085ME99) ; 2015 年安徽省省属社会公益类科研机构专项资金项目