FIELD TEST ON TIME EFFECT OF BEARING CAPACITY ON END-OPEN PILE AND END-CLOSED PILE

To research the differences of bearing capacity and the time-related setup of both end-open pile and end-closed pile in soft clay,field test of in-situ static pressures of 36 piles have been carried out within 72 days. Under such circumstances,the test results show that the minimum time effect coefficient of end-closed pile is 2.4 while end-open pile 3.6. Besides,the smaller the pile diameter is,the greater positive range and coefficient bearing capacity are. The bearing capacity increases with time,reaching steady value after 72 days' intermission but showing no distinctive raise later on. The original capacity of end-open pile is 60%–70% of end-closed one but with the same bearing capacity after intermission of 72 days. The soil length of end-open pile increases with the increase of pile diameter with time effect coefficient 1.4–1.6 times against that of the end-closed pile.