Cast-in-situ bored pile structure in karst intense area and construction method

The invention relates to a cast-in-situ bored pile structure in a karst intense area and a construction method. The cast-in-situ bored pile structure comprises each group of pre-stressed anchor cables; a plurality of groups of wall holes which are obliquely arranged downwards are excavated in the inner wall of a foundation pit; each pre-stressed anchor cable comprises a plurality of groups of flexible steel strands and anchoring bodies which are fixedly connected with the end parts of each group of steel strands; the outer sides of each set of steel strands are sleeved with steel pipes; grouting pipes are inserted into the steel pipes; a plurality of sets of through holes are formed in the peripheral faces of the steel pipes in a penetrating mode; the bottoms of the wall holes are expanded in a water high-pressure jetting mode to form cavities; the anchoring bodies are inserted into the cavities; the wall holes extend through a karst cave; and cement mortar is poured into the cavity and the wall holes to form