【摘要】 研制地球物理模型相似材料是地球物理探测模型试验成功的关键问题。针对地震波场、电磁场与直流电场多场相似的难题,应用多元地球物理场相似性原理,通过正交配比试验,研发了一种多元地球物理场综合模型试验相似材料。该材料以粉质黏土、碎石为骨料,以水泥为胶结剂,材料波速为236~1 260 m/s,电阻率为27.2~342.8Ω·m。通过正交试验发现影响试件波速的各因素主次顺序为压实度>含水率>水泥/黏土>碎石/黏土,影响试件电阻率的各因素主次顺序为含水率>压实度>碎石/黏土>水泥/黏土,影响综合地球物理相似材料波速与电阻率显著的两个因素为压实度与含水率。最后,开展隧道施工综合地球物理超前探测模型试验,得到具体模型试验要求的相似材料配比。TRT偏移图像上的强反射界面,电阻率反演图像上的低电阻率异常区域,与工程现场探测实例具有类似的异常体响应特征,综合探测结果与实际模型异常体位置较为一致,表明研发的相似材料能满足模拟综合地球物理场探测的需要。更多还原

【Abstract】 Development of model similitude material for geophysical fields is the key to the success of geophysical detection model test. According to the similar problem of the seismic wave field,electromagnetic field and the direct current field,a comprehensive model similitude material for multiple geophysical fields is developed by multiple geophysical fields similarity theorem and orthogonal experiment. It is composed of silty clay,gravel and cement. Silty clay and gravel are used as aggregated,and cement is used as the cementing agent. The velocity range of this material is about 236~1 260 m/s and the resistivity range is about 27.2~342.8 Ω ·m. The influent factors order of specimens wave velocity is compactness,moisture content,cement/clay and gravel/clay,that of specimen resistivity is moisture content,compactness,gravel/clay,cement/clay according to the results of the orthogonal experiment. And the compactness and moisture content is the two prominent influence factors for velocity and resistivity of the comprehensive similitude material. Finally,a large scale physical model packing test of multiple geophysical fields is conducted,and the similitude material proportioning for the concrete model test is obtained. Strong reflection interface of TRT(tunnel reflection tomography) offset and low resistivity anomaly of inversion image are obtained. The response characteristics in model test are similar to response characteristics in field. The detection result is consistent with actual location in model test,which indicates that the similitude material could meet comprehensive model test for the multiple geophysical fields.更多还原