复杂场地条件下的地球物理探测方法选择与工程实例

The Geophysical Methods Choice under the Complicated Site Condition and Case Study

某高速扩建工程约500m长路段为高填路段(填高最大处约34m),自通车以后,该路段沉降明显,持续不断,路面及边坡出现了不同程度的纵向裂缝。为查明造成路基沉降的空洞或不密实区,决定采用综合的物探手段进行探测。探测路段为单向四车道正常运营路段,交通繁忙,流量大,单向路面宽度为12m。要求测试期间不能停止交通,尽量少对正常交通造成干扰,避免路面交通阻塞。针对场地条件和要求,针对性地选择了探地雷达和微动探测两种无损物探方法,所选用的方法受场地条件干扰较少,外业测试效率高,仅需对占用的一半路面做好作业期间的交通布控,对车辆的正常通行影响较小。采用的物探方法合理、先进,探测成果可靠,划分了路面、路基病害的异常区域和不密实区域,为该路段的治理方案加固设计和施工提供了地质依据。

About 500m expansion of one highway is high-filled （with biggest filled height 34m）. Since it＇s open to the traffic, the road surface as well as slope appears vertical fissures to some extent. Geophysical methods are adopted to detect the potential cave or uncompacted location in the region. The site has four-lane with heavy traffic load, and the width of one single way is 12m. During the field test, disturbance to the normal traffic is required to reduce as less as possible. Two non - destructive geophysical methods -ground penetrating radar and microtremor survey are chosen, which has less disturbance and high efficiency, according to the requirements and site condition. Taking the advantages of only half of road. the pressure to the normal traffic will be less. The result shows that it is quite satisfactory to distinguish the uncompacted location and anomalous position in road bed and subgrade. So it provides a reasonable geologic data basis for the ground stabilization and construction.