Research on construction technology of large-diameter dense cast-in-place piles in covered karst areas
The construction of cast-in-place piles in karst areas often faces difficulties such as collapse,slurry leakage,and water inrush,especially for larger diameter piles.To solve the technical problems in construction of large-diameter cast-in-place piles in subway vehicle depots in karst areas,taking the pile foundation construction of a subway vehicle depot in Shenzhen karst area as an example,the construction technology of large-diameter cast-in-place piles in subway vehicle depots in karst areas is studied,and the construction methods for treating karst caves of different sizes are discussed.The construction effect of large-diameter pile foundations in karst areas is analyzed.The results show that when the karst cave is in an unfilled or semi filled state and the height of the cave is not greater than 1.0m,grouting method is used for treatment,and when the height of the cave is 1.0～5.0m,filling method is used for treatment.When thekarst cave is in a fully filled state and the height of the cave is not less than 1.0m,grouting method is used for treatment,and when the height of the karst cave is not less than 5.0m,the full casing drilling process is used to construct the cast-in-place pile.The compressive strength of concrete core sample of the pile body is 40.8～59.1MPa.After the completion of pile foundation construction in karst areas,the proportion of Class Ⅰ piles is 97.28％,and the proportion of Class Ⅱ piles is 2.72％.
万方数据
维普
