This paper discusses the construction methods of inner concrete in steel pipe concrete pile and proposes methods of concreting both in air and in water.

Field tests on composite foundation with concrete-cored sand-gravel piles;

The concrete-cored sand-gravel pile composite foundation technology applied to treat thick and soft foundation at bridge head from the idea of controlling post-construction and differential post-construction settlement is introduced in this paper.

Field tests study of concrete-cored sand-gravel piles applied to strengthen embankment engineering;

Soil squeezing effect of concrete-cored sand-gravel piles and excess pore water pressure dissipation;

It was introduced as a new ground treatment method that the composite foundation method named with concrete-cored sand-gravel piles was applied to the embankment strengthening.

It is proved that concrete-cored DCM pile has many advantages such as simple construction, little environmental disturbance, high bearing capacity, small settlement, low costs, and extensive adaptability in deep excavation engineering.

By combining with the work experiences,the paper emphasizes on the introduction of the common quality problems of the beating or pressing and grouting concrete piles construction,analyzes the reasons,and sums up some regular treatment methods and the technological measures,so as to avoid or reduce similar quality problems,and to ensure the safety of the buildings.