WATERWAY DREDGING WORKS IN CHINA-GEOLOGICAL EXPLORATION METHODS AND TECHNICAL REQUIREMENTS OF INVESTIGATION

摘要

Simple geological exploration, geophysical exploration, drilling and geotechnical sampling methods as well as the technical requirements of in/estigation for waterway dredging works in China are briefly described in this paper. Simple geological methods include punch exploration and simple auger sampler exploration.rnGeophysical methods cover the following: (1) electrical surveying (including the resistivity method, multi-electrode resistivity imaging, and imaging system of EH4 electrical conductivity); (2) seismic surveying (including mainly compression wave reflection methods) and (3) acoustic surveying (subbottom profiler exploration). Drilling is the main means of geological exploration for dredging works and involves the following: (1) drilling methods including mechanical rotary drilling and percussive-rotary drilling commonly used in the geological exploration of dredging works; (2) drilling operations, including open hole, overburden layer drilling , bedrock drilling , and slurry drilling; (3) drilling on water including drill site type , drilling barge location and drilling in pebble beds and (4) rock and soil sampling including the blowing-in method , pressing-in method and rotary method.rnTechnical requirements of investigation are described and include: (1) the requirements that the geologic investigation work for dredging works should satisfy; (2) the requirements that the layout of exploration lines and points should meet and (3) the requirements that one should meet while undertaking sub bottom profiler exploration.