摘要
在桥梁桩基础选址的勘察阶段,桩基础位置的岩面和岩溶探测是十分重要的工作。目前采用的主要孔内物探方法技术为跨孔CT技术。传统的跨孔CT技术在测线布置方面相对随意,在资料解译方面,也是基于每个跨孔CT二维拟断面单独进行解译。因此,无法刻画出整个测区岩面和岩溶的形态。为了解决上述问题,需要采用拟三维跨孔地震波CT探测技术。其主要难点是拟三维数据的采集和三维视图的生成。为了实现拟三维探测,在数据采集时,采用网格方式布置测线,完成三维网格节点数据的采集。在数据处理和资料解译时,通过Voxler平台对数据进行三维网格化,完成三维可视化成图,并利用三维视图进行解译形成三维成果。应用实例中,展示了整个测区地质构造、基岩面及岩溶的三维空间形态。通过对断裂构造的分析,确定了岩体分布范围,指导断裂区域桩基础类型的选择,在断裂的上盘采用摩擦桩,下盘采用端承桩。通过三维基岩面形态,避免了桩底位置半边岩的情况以及对岩溶的误判,进而指导岩溶的治理工作。通过分析岩溶的三维分布,理清岩溶间的连通关系以及确定了桩身、桩底与岩溶的位置关系,为桩基础的桩长设计以及岩溶的治理提供了依据。
In limestone area,karst seriously affects the stability of bridge foundation,it must be treated.It is very important to investigate the bedrock face and karst of pile foundation in the stage of site selection of bridge pile foundation.The traditional cross-hole tomography as the main method of geophysical exploration is relatively arbitrary in line arrangement.In terms of data interpretation,based on each cross-hole tomography two-dimensional pseudo-section to interpret separately,it is therefore impossible to characterize the morphology of rock face and karst in the whole survey area.In order to solve the above problem,it is necessary to adopt quasi-three-dimensional cross-hole seismic-wave tomography detection technology.The main difficulty lies in the acquisition of quasi-three-dimensional data and the generation of three-dimensional view.In order to realize the quasi-three-dimensional detection,grid layout of survey lines is adopted to complete the data acquisition of three-dimensional grid nodes.In the process of data processing and data interpretation,the Voxler platform is used to conduct three-dimensional meshing of the data,complete three-dimensional visualization into graphs,and use three-dimensional view for interpretation to form three-dimensional results.The application results justify the three-dimensional spatial morphology of geologic structure,bedrock face and karst in the whole survey area.Based on the analysis of fracture structure,the distribution range of rock mass is determined and the selection of pile foundation type in the fracture area is guided.Friction pile is used in the fracture hanging wall and end bearing pile is used in the footer.Through the shape of the three-dimensional form of the rock face,the situation of half rock at pile bottom and the misjudgment of karst can be avoided,so as to guide the treatment of karst.By analyzing the three-dimensional distribution of karst,the connection between karst is clarified and the position relationship between pile body,pile bottom and kars
作者
喻波
Yu Bo(Geologic and Geophysical Engineering Exploration Institute of Guangdong Province,Guangzhou Guangdong 510800,China)
出处
《工程地球物理学报》
2023年第4期491-499,共9页
Chinese Journal of Engineering Geophysics
基金
珠海城市地质调查(含信息化)项目(编号:MZCD-2201-008)
广东省地质物探工程勘察院基础探测的物探关键技术研究与应用项目(编号:RD10)。
关键词
跨孔地震波CT
三维可视化
岩溶
桥梁桩基础
cross-hole seismic-wave tomography
three-dimensional visualization
karst
bridge pile foundation
