温州超固结软黏土次固结试验研究

EXPERIMENTAL STUDY OF SECONDARY CONSOLIDATION OF WENZHOU OVERCONSOLIDATED SOFT CLAY

为研究超固结比对软黏土次固结特性的影响,对温州正常固结和超固结软黏土开展长期一维压缩试验,系统性研究先期固结压力、超固结比等因素对次固结变形和次固结系数的影响。试验结果表明:先期固结压力对软黏土固结变形发展曲线有显著影响,固结压力小于先期固结压力时,曲线变化较小,接近直线,此时次固结系数随固结压力增长较快;当固结压力超过先期固结压力后,曲线变化明显,呈三段式发展,次固结系数随固结压力的增大略有减小,最后趋向某一稳定值。软黏土的次固结系数随超固结比的增大而减小,通过试验结果分析得到了次固结系数随超固结比变化的计算式。次固结变形随时间的变化在双对数坐标下近似为直线关系,基于此建立了次固结变形累积方程。

One-dimensional consolidation tests of normal consolidation and overeonsolidated Wenzhou soft clay were conducted to research the influence of over consolidation ratio on secondary consolidation behavior. The influence of preconsolidation pressures and over consolidation ratio on secondary consolidation deformation and secondary consolidation coefficient were studied systematically. Results showed that preconsolidation pressures had significant influence on the curves of consolidation deformation development of soft clay, when the consolidation pressures were less than the preconsolidation pressures, curves of deformation were nearly linear and secondary consolidation coefficients were increased rapidly with consolidation pressures; with the consolidation pressures being over preconsolidation pressures, curves were developded with three-stage obviously. Secondary consolidation coefficients were decreased slightly with consolidation pressures increasing and finally kept a stable values. Secondary consolidation coefficients were decreased with over consolidation ratio increasing, then the formula of change in secondary consolidation coefficients with the over consolidation ratio was got by analyzing the test results. Secondary consolidation deformation changed over time in the double logarithmic coordinates were approximately linear, besed on which accumulation equations of secondary consolidation deformation were establishded.