回填钢管管周土压力分布特性研究

目前市政行业广泛采用Spangler理论进行回填钢管的设计,但水利水电行业中钢管规模和运行条件与市政行业存在较大差距,Spangler理论的适用性有待研究。基于有限单元法,考虑管土之间的接触作用,建立回填钢管三维有限元计算模型,计算不同埋设深度、开槽宽度、管道刚度下回填钢管的管周土压力,通过绘制管周土压力分布图研究管周土压力的分布特性及Spangler理论的适用性。结果表明,竖直土压力在回填钢管管顶和管底处有"波谷"产生,在高埋深、小槽宽时尤为明显;此外,回填钢管刚度越大,管顶土压力越接近抛物线分布,管腰处出现的"波谷"越明显。总体而言,Spangler理论一般更适用于埋深小于2m、管道刚度t/D值小于1/120的回填管道,在实际工程回填钢管的设计中要加以判断。

Study on Distribution Characteristics of Soil Pressure around Buried Steel Pipe

At present,Spangler theory is widely used in the design of buried steel pipe in municipal industry,but there is a large gap between the scale and operation conditions of steel pipe in water conservancy and hydropower industry and municipal industry,so the applicability of Spangler theory needs to be studied.Based on the finite element method,considering the contact between pipe and soil,a three-dimensional finite element calculation model of buried steel pipe is established to calculate the soil pressure around the buried steel pipe under different buried depth,groove width and pipe stiffness.The distribution characteristics of soil pressure around the pipe and the applicability of Spangler theory are studied by drawing the distribution map of soil pressure around the pipe.The results show that the vertical earth pressure has a "trough" at the top and bottom of the buried steel pipe,especially in the case of high buried depth and small groove width;In addition,the greater the stiffness of the buried steel pipe,the closer the earth pressure at the top of the pipe is,the more obvious the "trough" appears at the waist of the pipe.Generally speaking,Spangler theory is more suitable for buried pipes with buried depth less than 2 mand pipe stiffness t/D value less than 1/120,which should be judged in the design of buried steel pipe in practical engineering.