Influences of Geotechnical Engineering Condition
Geotechnical engineering condition is an essential foundation to definite design of supporting method, excavation method, precipitation method and ground reinforce method. The main factors influencing supporting design are as following:
1. Soil layer condition.
Constituent of stratum, classification and distribution of soil layer, physical property and parameter of soil;
Soil layer’s expansibility, collapsibility, thixotropy, earthquake liquefaction, frost heaving property and humidification;
The weak structure surface’s distribution and character, filling condition, roughness and syntagmatic relation in soil layer;
Existence and distribution of karst, soil cave and other underground caverns.
2. Underground water condition.
Water height and principle of speed up/down of aquifer (including perched water);
Replenishment, dynamic change of aquifer and contact relation with surrounding water;
Vertical and horizontal permeability coefficient of water in soil layer;
Water quality and water pressure of phreatic water and water velocity and flow direction of underground storage layer.
When choosing supporting design, soil nail wall is frequently-used and quite efficient. It combines drilling, grouting and anchoring together to bond soil layer with soil nail wall, which enhances integrity, cohesiveness and pressure resistance of soil layer. So far, many projects have adopted this supporting method and have great benefit.