真空预压下地基承载力提高计算方法研究

Research on Caculation Method for Bearing Capacity Improvement under Vacuum Preloading

基于莫尔—库仑破坏准则的弹塑性理论,对真空预压地基承载力提高计算公式进行了推导,得到考虑地基固结程度及真空度衰减的简易计算公式。并修正了不排水条件下采用CU总应力强度指标计算地基承载力的方法,建立其与不排水抗剪强度及竖向有效应力增量的关系式。通过两个工程实例对计算公式的精度进行了验证,确认了公式的可靠性,证明该计算公式能够应用到工程实践中,为需要快速计算出地基承载力增量的工程服务。

Based on Mohr-Coulomb’ failure criterion and elastic-plastic theory ,the formula for the bearing capacity im-provement of vacuum preloading foundation is deduced here .Considering the consolidation degree and vacuum degree at-tenuation ,the simple calculation formula is got by using the strength index of total stress in CU test .Meanwhile the rela-tions between the bearing capacity and undrained shear strength as well as the bearing capacity and vertical effective stress increment are presented .By two engineering examples ,the accuracy of the calculation formula and the reliability of the formula are verified .Therefore it is shown that the formula could be applied in engineering practices and served for the engineerings to get the bearing-capacity imcrement under vacuum preloading quickly .