有机固化剂作用下重金属污染土的力学体变特性

Mechanical Volumetric-Change Characteristic of Heavy Metal-Contaminated Soil with Organic Curing Agent

在低围压90、120、240 k Pa和相对中高围压600、900、1 200 k Pa的条件下,对原状土、重金属污染土与添加有机固化剂(环氧固化剂1.5%、环氧固化促进剂2.6%、稀释剂1.0%)的重金属污染土试样进行了三轴固结排水剪切对比试验,并绘制了3种土样的力学体变特性曲线.试验结果表明:添加有机固化剂能显著提高重金属污染土的强度,有效改善重金属污染土在低围压作用条件下体胀、中高围压下作用下体缩的力学特性.根据Pietruszczak硬化准则建立了重金属污染土的双屈服面体变本构模型,该模型克服了传统单曲面模型不能描述污染土体变临界状态的缺陷,较为合理地反映了重金属污染土的体变过程.

In the investigation, a consolidated drained tri-axial comparison test was performed to analyze the undis- turbed soil, the heavy metal-contaminated soil and the heavy metal-contaminated soil with the organic curing agent （ epoxy curing agent of 1.5% , epoxy curing catalyst of 2.6% , thinner of 1.0% ）under the low confined pressures of 90, 120, 240 kPa and the relatively high confined pressures of 600, 900, 1 200 kPa, and the mechanical volu- metric-change characteristic curves of the three kinds of soils were drawn up. The results show that the organic cu- ring agent can dramatically improve the strength of the heavy metal contaminated soil, and effectively ameliorate its mechanical behavior of expanding under a low confined pressure and of contracting under a relatively high confined pressure. In addition, a two-yield-surfaces volumetric-change constitutive model of the heavy metal metal-contami- nated soil is established based on the Pietruszczak hardening rule. This model overcomes the deficiency of the single yield surface model that can＇t be used to describe the critical state of the volumetric change of the heavy metal-con- taminated soil, and it also reflects the volumetric change more reasonably.