玻璃钢夹砂管管土摩擦系数室内模型试验研究

Research on Pipe-soil Friction Coefficient of FRPM Pipe by Laboratory Model Test

通过顶管法室内模型试验，研究了玻璃钢夹砂管与回填中砂之间的摩擦系数。分析了埋深、管径和压实度对管土摩擦系数的影响。试验结果表明：（1）松砂条件下，管身摩阻力随顶进位移的增大呈线性增长，当顶进位移增大到2～3时，管身摩阻力达到峰值，最后趋于稳定；随着埋深的增大，摩擦系数逐渐增大，但增量逐渐变小，其值在0．26～0．28之间。（2）管径的变化基本上不会对玻璃钢管道与砂土之间的摩擦系数产生影响。在管径不变的情况下，随着埋深的增加，管身摩阻力也随之增加。（3）随着压实度的增大，摩擦系数也随之增大，压实度从75％增至95％时，摩擦系数从0．26增至0．32，说明压实度的变化对玻璃钢管道与砂土之间的摩擦系数的影响很大。

Through laboratory model tests of the pipe jacking method,the friction coefficient between FRPM pipe and backfilled sand is studied. Effects of burying depth,pipe diameter and compaction degree on pipe-soil friction coefficient are analyzed. Results from model tests show that:( 1) Pipe friction force increases linearly with the increasing of jacking displacement in the condition of loose sand. It will reach to the maximum value and then tend to be stable under test conditions when jacking displacements reach about 2 ~ 3 mm; Friction coefficient increases gradually with the increasing of burying depth,but its increment which is 0. 26 ~ 0. 28 reduces gradually.( 2) The friction coefficient of FRPM pipe and sandy soil will not be influence by pipe diameter on the whole. Pipe friction force increases with the increasing of burying depth in the condition of constant pipe diameter.( 3) Increment of compaction degree will lead to the increment of friction coefficient. When compaction degree increases from 75% to 95%,friction coefficient increases from 0. 26 to 0. 32. It shows that compaction degree influences the friction coefficient of FRPM pipe and sandy soil greatly.