DMTC消散试验计算水平固结系数模型研究

Research on the Calculation Model of Horizontal Consolidation Coefficient from DMTC Dissipation Test

研究目的:扁板侧胀试验是一种先进的原位测试技术,与CPTU孔压消散试验相比,DMTC消散试验具有诸多优点。通过本研究,拟建立DMTC消散试验计算水平固结系数的数学模型,并通过对比试验确定计算模型的关键参数——时间因数。研究结论:(1)对于饱和软黏性土,DMTC消散试验测试的p_2值近似等于孔隙水压力,而且DMTC消散曲线与孔压消散曲线能够很好地匹配,因此借鉴孔压消散理论建立DMTC消散试验计算水平固结系数模型;(2)DMTC消散试验实测曲线与u_2型孔压消散理论曲线拟合相近程度最高,因此通过开展DMTC与u_2型孔压消散对比试验确定模型关键参数——时间因数;(3)DMTC消散试验计算模型获取的水平固结系数与孔压消散试验较为接近,比室内试验约大1个数量级,这与其他研究者的成果是一致的;(4)对比试验证明,本文建立的DMTC消散试验计算水平固结系数的方法是可靠的。

Research purposes： The flat dilatometer test is an advanced in -situ test technique. Compared to the CPTU pore pressure dissipation test, the DMTC dissipation test has many advantages. Through this study, a mathematical model for calculating the coefficient of horizontal consolidation of DMTC dissipation test is established, and the key parameters -time factor in the mathematical model by comparative test is determined. Research conclusions ： （ 1 ） For saturated soft cohesive soil, the P2 value by the DMTC dissipation test is approximately equal to the pore water pressure, and the DMTC dissipation curve matches well with the pore pressure dissipation curve. Therefore, the mathematical model for calculating the coefficient of horizontal consolidation of DMTC dissipation test can be established based on the pore pressure dissipation theory. （2） DMTC dissipation test curve and u2 pore pressure dissipation theory curve have the highest fitting degree of similarity, so it can be carried out the DMTC and u2 type pore pressure dissipation test to determine the model parameters - time factor. （3） The horizontal consolidation coefficient obtained by DMTC dissipation test calculation model is closer than the pore pressure dissipation test, and it is an order of magnitude greater than the laboratory odometer tests, which is consistent with other scholars research results. （4） The comparative tests show that the mathematical model for calculating the coefficient of horizontal consolidation of DMTC dissipation test is reliable.