Engineering Geological Characteristics of Houhai Weathered Deep Trough in Shenzhen Bay Area

There are many weathered deep troughs in Shenzhen Bay area, among which Houhai weathered deep trough is the largest exposed at present, with a bottom depth of 175.9 m. The existence of weathered deep troughs causes trouble to pile foundation engineering. The development scale and geotechnical engineering characteristics of weathered deep trough were analyzed, and the characteristics of fracture development in weathered deep trough were emphatically discussed. The results show that the fracture zone is the controlling factor for the formation of weathering deep trough. The Shenzhen Bay area is intersected by the northeast Wuhua-Shenzhen fault zone and the northwest Shiziyang-Pearl River Mouth fault zone. The fracture bandwidth and fracture mechanical properties are both compressional and tensional, which are conducive to the propagation of weathering deep. The fully and strongly weathered rock in Houhai weathered deep trough are particularly deep and the strength of weathered rock is low.