高压旋喷桩复合地基竖向承载特性数值模拟研究

Numerical Simulation Study on Vertical Bearing Characteristics of High-pressure Rotary Pile Composite Foundation

为优化高压旋喷桩复合地基在施工前后的竖向承载性能,文中以盐坝高速市政化改造工程为对象,通过模拟软件对高压旋喷桩复合地基进行三维建模,并从桩长、间距、强度、直径及垫层厚度5个方面对高压旋喷桩复合地基进行沉降模拟。结果显示,高压旋喷桩复合地基各项参数中桩长、水泥土桩直径和桩间距对沉降的影响最为明显,桩长和水泥土桩直径与地基沉降量成反比,桩间距的大小与复合地基沉降量成正比。水泥土桩强度与垫层强度对沉降影响较小,主要荷载均由预制管桩所承担。基于经济效益考虑,建议水泥土桩和垫层的强度选择区间分别为100~200 MPa和100~300 MPa。

In order to optimize the vertical bearing capacity of high-pressure jet grouting pile composite foundation before and after construction,this paper takes the high-speed municipal reconstruction project of salt dam as the object,the 3D model of high-pressure jet grouting pile composite foundation was built by simulation software,the settlement of high pressure jet grouting pile composite foundation is simulated from five aspects of pile length,space,strength,diameter and cushion thickness,the pile length,the diameter of cement-soil pile and the distance between piles have the most obvious influence on the settlement of high-pressure jet grouting pile composite foundation,and the pile length and the diameter of cement-soil pile are inversely proportional to the settlement of foundation,the pile spacing is proportional to the settlement of Composite Foundation.The strength of cement-soil pile and cushion has little influence on settlement,and the main load is carried by precast pipe pile.Considering the economic benefit,the strength selection interval of cement-soil pile and cushion is suggested to be 100MPa-200MPa and 100MPa-300MPa respectively.