Research On Bearing Capacity Of Double Static Pressure Pipe Pile

In the case of ensuring the strength of the pile body,the vertical compressive bearing capacity of a single pile depends on the pile side friction resistance and pile end resistance.The resistance of the pile end can be improved by reaching a hard and dense rock and soil layer.Double static pressure pipe pile is a new pile sinking process.The pile body material is high-strength prestressed concrete pipe pile(PHC pipe pile).At the same time,static pressure is applied at the bottom of the pile to press the pipe pile into the soil,referred to as JD-S pile in engineering.Double static pressure pipe pile has the advantages of higher pile strength,strong penetration ability,lower cost,and small settlement.Compared with traditional prefabricated hollow pipe pile,this pile overcomes the smaller final pressure of traditional prefabricated pile.The shortcomings of being difficult to pass through the hard interlayer allow the pile end to reach a better pile end bearing layer.The load-bearing mechanism of the internal pressure bar of the double static pressure pile feeder,a key component of the process,was analyzed indoors.The bearing capacity test was carried out on two internal pressure bars in the room.To prove the stability of the critical load capacity of the internal pressure bar and the restriction of the pipe pile on the internal pressure bar.The stress mechanism and bearing capacity of the double static pressure pipe piles were studied,and the typical stratum was selected to conduct two groups of 12 piles of single pile vertical compressive static load test,which passed the Q_s,s-lg Q and s-lgt curves Determine the bearing capacity of the test pile,and use the theoretical formula to calculate the theoretical bearing capacity of the test pile.Compare the results of the two methods.The data shows that this method greatly improves the bearing capacity.The ABAQUS software was used to simulate the pile sinking process,soil squeezing effect,vertical compressive bearing capacity of single pile,and three pile bearing capacity simulation of double static pressure pipe pile and static pressure pipe pile.High,no obvious soil squeezing effect;comparing the static load test value,theoretical calculation value and simulation value,the three results are similar;the data results show that the bearing capacity of the double static pressure pipe pile is significantly improved compared with the static pressure pipe pile.