The Settlement Calculation And Designment Analysis Of Rigid-soften Composite Piles Foundation In Deep And Thick Soft Soil

Deep and thick soft soil is extensively distributed along the river and wreath lake and etc. When introduced general pile foundation without thinked the toft power under the foundation board, piles needs so many that the structure of soft soil is destroyed and possibly crushed soil problem be caused. For the sake of insuring the safety and as far as possible developing a mechanics function for pile-soil system, we can use rigid-soften composite piles foundation to handle the soft soil.The key to apply rigid-soften composite piles foundation is to control its settlement. Firstly, on the base of analysis and summarize already existing every kind of means to calculate the settlement of the foundation, and combinating stress peculiarity of the rigid pile in rigid-soften composite piles foundation, lodge a new method named utmost stress to calculate the settlement of it. It was proved useful with the practical example. Besides that, bring forward a criterion that the calculation of the settlement must be bigger than the observation of it for 30% to discriminate a method between safe and unsafe.Secondly, by using the great FEM programme, analyzes the mechanism of bearing and deformation of rigid-soften composite piles foundation. Draw a conclusion: exist a specific value, when the number of the rigid pile less than it, increase the number of the rigid pile, effect of reducing the settlement of rigid-soften composite piles foundation is distinct, on the contrary, when the number of the rigid pile more than it, increase the number of the rigid pile, effect of reducing the settlement of rigid-soften composite piles foundation is indistinct.Finally, analyze and sum up some important design's constitutes of the rigid-soften composite piles foundation. Put an table forward to calculate the safety coefficient. Commend a modus operandi for design of the padding. Besides, confirm a principle of according as the bearing under the end of the soften pile to determine the length of the soften-short pile.