ANALYSIS THE CAUSE OF UPPER CHALK KARST PHENOMENA IN HUANGHUAGANG AREA OF WEST GUANGZHOU

Upper Chalk Karst is exist in Huanghuagang area of west Guangzhou, the probability of water-eroded cave existing in one drill is 4 to 40 percent, the factors main affecting developing degree of the water-eroded cave include the distributing of limestone, the acting of conformation, the denudation of stratum and the dynamical action of ground water. the dimensions of it is smaller, the layers is less, nothing fill in 80 percent of it, existing the whole airslake soft plasticity stone strap above the water-eroded cave, no accompany by the karren and solution groove, all of these are the characters of the Upper Chalk Karst. Considering the distribution of the Upper Chalk Karst is very misproportion, therefore, the feasibility of engineering construction and the selection of base foundation are specially discussed in this paper, the result is hoped to have some reference to the engineering construction in this area.