粘土中钻孔灌注桩墙体支护开挖弯矩数值模拟研究

NUMERICAL SIMULATION STUDY ON THE BENDING MOMENT IN WALL SUPPORT EXCAVATION OF BORED PILE IN CLAY

针对粘土中钻孔灌注桩墙体支护开挖弯矩数值进行模拟,研究弯矩数值对钻孔灌注桩墙体支护开挖工程的影响程度。采用有限元软件Midas NX,结合模型构建的四点原则,通过计算墙体支护材料的弹性模量、体积模量和剪切模型,得到相应的墙体支护参数,结合工程的实际情况,确定模拟模型的边界范围,通过对墙体外的地下水的降水处理,构建相应的钻孔灌注桩墙体支护模拟模型,并对测点进行布置。利用上述参数,进行模拟测试,并通过布设的测点记录墙体支护开挖后桩身的变形情况。钻孔灌注桩墙体支护开挖后,桩身的最大变形量为6.02 mm,桩身的弯矩值为500 KN·m。钻孔灌注桩墙体支护的弯矩值受到多种因素的影响,其中变形量对桩身弯矩值的影响最大。

The influence of the bending moment in wall support excavation of bored piles in clay was studied through simulation of the bending moment in wall support excavation engineering.The corresponding wall support parameters were obtained by calculating the elastic modulus,volume modulus and shear model of wall support materials with the finite element software Midas NX,in accordance with four modeling principles.The boundary range of the simulation model was determined based on engineering conditions.In addition,the wall support simulation model for bored piles was built through reducing the groundwater level outside the wall,and measurement points were set up.The simulation test is carried out with the above parameters,and the deformation of the pile body after wall support excavation was recorded based on the measurement points.After the wall support excavation of the bored pile,the maximum deformation of the pile body was 6.02mm and its bending moment was 500KN·m.The bending moment of the wall support of the bore pile is affected by many factors,among which the deformation has the greatest influence.