Waterway Dredging Works in China-Geological Exploration Methods and Technical Requirements of Investigation
Type:
Presented during:
WODCON XVIII - 2007 Orlando, Florida, USA
Authors:
Dafu
Abstract: Simple geological exploration, geophysical exploration, drilling and geotechnical sampling methods as well as the technical requirements of investigation for waterway dredging works in China are briefly described in this paper. Simple geological methods include punch exploration and simple auger sampler exploration.
Geophysical 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.
Technical 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.
Keywords: China; waterway dredging works; geological exploration methods; technical requirements of investigation