In-situ experimental study of load transfer properties of thin-wall tubular pile in tidal soil area

At present, few in-situ experiments have been conducted on thin-wall tubular piles about load transfer properties, and few studies have been reported about thin-wall tubular piles in tidal soil foundation treatment. Hence, based on the region #1 of the first-period peninsula in Wenzhou tidal land, in-situ static load tests were performed on thin-wall tubular piles. According to test data, load transfer properties were analyzed. The results indicate that about 75% of the load at pile head is shared by the outer frictional resistance, and the long piles work as end-bearing frictional piles under the maximum load while the short piles work as pure frictional piles. In order to increase bearing capacity, thin-wall tubular pile can be lengthened and widened appropriately. Industrial workshops within 5 floors can be built in this area. The axial force decreases with the increasing depth, and the outer frictional resistances of upper and lower soils work asynchronously. With the increase of load, side resistance softening happens when the frictional resistance of upper soil is up to the ultimate value. The inner frictional resistance is generated from the end of pile and it is about 20%-25% of the outer frictional resistance. When the thin-wall tubular piles are applied to reinforcement of tidal soil foundation, the contribution of inner frictional resistance of soil to bearing capacity should be taken into account.