Analysis and discussion of several issues of pile foundation construction in karst region of Tangshan

Based on the project cases in Karst region of Tangshan in recent years, some issues occurred in karst treatment and pile foundation construction are analyzed according to the differences with litho logy, karst developing characteristic and karst treatment method. The methods of karst treatment together with the construction technology of pile foundation are sumarized combining with the technical measures and the application of pile foundation adopted in karst treatment. Meanwhile, comprehensive analysis of the measured values of end bearing, skin friction, pile body stress, pile body compression and pile top settlement is conducted according to the core recovery and RQD of the pile tip resistant layer. The results are regarded as the basis of treatment method and design in similar projects. Aiming at karst developing characteristics and common issues in pile construction, effective construction method, technology and measures are proposed, and it may helpful for the pile foundation construction in similar projects.