【摘要】 借助霍耳局部应变传感器和非接触传感器,对传统三轴试验进行改进,研究北京典型土体的小应变刚度及其随应变变化的规律;通过引入二次函数形式表述的应变历史,分析小应变刚度的变化,采用修正Hardin-Drnevich模型表征小应变力学特性。以浅埋暗挖工法地铁隧道下穿北辰桥为例进行既有桥梁沉降的数值模拟,并与实际监测结果进行对比。结果表明:运用考虑小应变特性的模型得到的预测值与监测结果较为吻合,与常规模型的预测结果相比,预测精度最大提高26%。更多还原

【Abstract】 With Hall effect local strain and non-contact transducers,the traditional triaxial test was improved to study the small strain stiffness and its change law along with the strain in the typical soil of Beijing.The change law of small strain stiffness was analyzed with the strain history formulated in the form of quadratic function and the mechanical properties of the small strain were characterized by the modified Hardin-Drnevich model.Numerical simulation was carried through on the settlement of the existing bridge by taking the subway tunnel with shallow excavaction tunneling method underpassing Beichen Bridge as an example.The simulation results were compared with practical monitoring results.Results show that the model prediction values considering the characteristics of small strain agree well with the monitoring results.Compared with the prediction results obtained by the conventional model,the prediction accuracy has been improved by 26% at the most.更多还原