Bearing Capacity Experimental Study And Settlement Calculation Of Cast-in-Situ Piles With Expanded Branches Or Plates Under Vertically Loading

Cast-in-situ piles with expanded branches or plates based on common concrete bored piles are a new type of piles foundation, which have been marked economic and social benefits.Based on plate loading test in-situ, the method of Geddes' formula, finite element method and the relative theory of method of code, the paper makes a thorough study on the bearing capacity and settlement of vertically loading cast-in-situ piles with expanded branches and plates, and the major results are as follows:(1) Based on the results of plate loading test in-situ, the single pile settlement behavior is analyzed. It is pointed out that its load-settlement(Q-s) curve as tardy deformation.(2) It has been shown that the cast-in-situ piles with expanded branches or plates can provide a higher bearing capacity than common concrete bored piles. In this paper, the quantitative analysis for economics is also conducted.(3) Based on Geddes' formula, the author develops a settlement calculating formula suitable for the single pile of cast-in-situ piles with expanded branches or plates. And its feasibility is verified through finite element method and a case history analysis.(4) By using finite element method, the settlement and stress distributions both cast-in-situ piles with expanded branches or plates and common concrete bored pile have been comparied. The main differences are pointed out, which may be useful for pile design.(5) According to the relative theory of method of code, and connecting the project, compiling computer program ,settlements of the pile groups for cast-in-situ piles with expanded branches or plates are carried out and analyzed.