Constructing Techniques And Experimental Study In Situ Of The Cast-in-Situ Piles With Expanded-Base And Post-Pressure Grouting

After many years development, Cast-in-situ piles with expanded-base and cast-in-situ piles with post-pressure grouting are widely used in different projects. But the two types of piles have their own disadvantages. In this paper, through intercrossing and combining the two constructing techniques author bring forward a new type of constructing technique-the cast-in-situ pile with expanded-base and post-pressure grouting. And referring to the existing constructing equipment, the constructing technique of the cast-in-situ pile with expanded-base and post-pressure grouting is studied.Based on the static loading test and stress testing of piles in situ of the project "Taiyuan second long-distance telegraphic hinge", some researches below have been conducted in this paper. The paper consists of the following two parts: the comparisons of load transfer feature of the resistance among the four types of piles (that is, the normal cast-in-situ pile, the cast-in-situ pile with post-pressure grouting, the cast-in-situ pilewith expanded-base, the cast-in-situ pile with expanded-base and post-pressure grouting), the bearing capacity of piles affected respectively by the two types of construction technique. The results of researches prove that by comparison with normal one, the cast-in-situ piles with expanded-base and post-pressure grouting have the advantages of low settlement and high bearing capacity. The results of this paper may be referred to the design and engineering application of this new type of pile.