On construction technique of shaping cast-in-place bored pile head at a time;

The underground construction of an edifice in Beijing has as many pile heads as more than 180 pieces.

Adding CCCW agent to cement mortar makes surface treatment and curing of concrete more convenient and waterproofing design of construction joint,pile head and post-pouring joint simpler.

The construction method, equipment and bore hole wall protection technology of the 100m long bored pile are described, with the analysis on the feasibility of suction reverse circulation method, balled bit problem in seriously weathered layer and technical measures for solving the problem presente

This paper analyzes the contradictions between waterproof closure and structural integrity, discusses the key problems that should be solved to satisfy the requirements of waterproofing closure, and advances some measures for and principles of the waterproofing work s on the grouting pile head and basement foundation slab.

The factors which influence head of tamping reamed pile s quality is analyzed through practical example of project,and measures in controling head of tamping reamed pile s quality is given.