Study On The Mechanical Properties Of The Pile Under The Combined Effect Of Vertical And Horizontal Loads In Marine Soft Soil

In recent years, with the development of national economy, the contradictionbetween a large population and relatively little land is becoming increasingly serious.How to explore the marine soft soil has become a problem that needs to be addressedurgently. However, it is inappropriate to build structures on this area directly because ofgreat settlement, slow drainage consolidation and poor stability. Therefore, it is veryimportant to solve this fundamental problem in the aspect of design and processing.Based on setting marine soft soil in Lianyungang, this study focused on pilefoundation according to soil test and pile field test. On the other hand, it conductstheoretical derivation on pile by using differential equations, numerical analysis withMathematica9.0to find a suitable calculation model for pile in marine soft soil.Firstly, it carried out the research of marine soft soil test and pile field test underhorizontal load. The soil test determined the physical and mechanical properties ofmarine soft soil in Lianyungang with five soil test. Based on the soil test, it put forwardthe simplified model of "hard-soft-hard" for marine soft soil. Through measuring theground and pile horizontal displacement and angle in field test, it can get maximumdisplacement and maximum load; analyze the charting and the critical load andhorizontal displacement.Theoretical analysis of pile is carried on by using differential equations. Combinedwith a simplified model of soil, it researched the bearing characteristic of pile under thedifferent load and established calculation model under the different load. Thus, bycompared with the field test results and the geotechnical investigation report to compare,it verified the accuracy of the calculation model. Meanwhile, based on simplifyingcalculation method of pile under horizontal load, it provided a new calculation methodof pile under horizontal load—differential segmented superposition method which iscloser to the pile calculated field test results than compared with the originalspecification and possessed better reliability and accuracy.According to the model under two loads, it can deduce the power series solutionsof the pile under the combined effect of vertical and horizontal loads to differentialequations. Through the numerical analysis for the differential equations withMathematica9.0and data processing by Excel, it can obtain the pile of horizontaldisplacement, strength and ultimate destruction region under the combined effect ofvertical and horizontal loads to verify the accuracy of the calculation method.