黄土中爆炸挤密实验与数值模拟

Experiment and numerical simulation of explosion compaction in loess

为研究爆炸挤密加固技术在黄土中的应用,规避在既有公路上进行大规模爆炸挤密现场实验的风险,验证借助计算机软件进行数值模拟的可行性和可靠性,先设计实施了小型爆炸挤密室外实验,再利用室外实验的材料参数和几何尺寸建立与各实验工况相对应的有限元模型,利用ANSYS/LS-DYNA进行数值模拟,通过将爆腔体积、爆后土壤密度和作用于土壤的峰值压应力3个方面对数值模拟结果和实测结果进行对比,验证了将ANSYS/LS-DYNA用于数值模拟爆炸挤密技术加固黄土的可行性和可靠性,并得出上述三个方面的变化规律,可为根据现场路基状况和几何尺寸进行数值模拟提供借鉴和参考。

In this work we at first designed and performed some small-scale explosion compaction(EC)outdoor experiments to study the application of EC technology in loess and to verify the feasibility and reliability of numerical simulation by computer software so that the risk of field experiments of EC on existing highways can be avoided.Then,we established the finite element models using the material parameters and the geometric dimensions of the outdoor experiments.Numerical simulations were carried out using ANSYS/LS-DYNA in combination with the above finite element models.By comparing the numerical simulation results with the measured ones in three aspects:the volume of the explosion cavities,the soil density after EC and the peak compressive stress acting on the soil,the feasibility and reliability of using ANSYS/LS-DYNA to simulate the EC of loess were verified.Moreover,the variation laws in the above three aspects were obtained.Our work can provide reference for numerical simulation of EC according to the conditions and the geometrical dimensions of actual loess subgrade.