岩石流变对不同锚杆应力影响的数值分析

针对岩土工程中的锚杆预应力存在的时间效应,运用有限元法求解岩石流变对不同锚杆应力分布及变化趋势的影响.为验证用有限元法求解流变问题的准确性,分别求得均布载荷作用下Maxwell体和Burgers体简支梁的有限元解与解析解,其结果非常接近.建立全长黏结式锚杆轴对称模型,在不考虑流变的前提下求得锚杆轴向应力的有限元解,其与基于Mindlin问题的解析解分布趋势一致,从而验证该有限元模型的可行性,进而求得岩石流变对钢锚杆、FRP锚杆和MFRP锚杆轴向应力的影响.结果表明在工程应用中,由于抗腐蚀而采用FRP锚杆或MFRP锚杆的同时,考虑流变对其应力的影响具有重要意义.

Numerical analysis on effect of rock rheology on different anchor stress

As to the time effect of anchor pre stress in geotechnical engineering, the stress distribution and the trend of different anchors influenced by rock rheology are obtained by finite element method. To verify the accuracy of solving rheology problems by finite element method, the finite element solutions and analytical solutions of a Maxwell beam and a Burgers beam under the uniform load effect are obtained, and the two kinds of solutions are very close. An axisymmetric model of wholly grouted anchor is built, and the finite element solution of axial stress of the anchor is calculated without considering rock rheology. The distribution trend is the same as that of the analytical solution based on the Mindlin problem, which verifies the feasibility of the finite element model. Thus the effect of rock rheology on steel, FRP and MFRP anchors is obtained. The results show that the rheology effects should be considered while using FRP or MFRP anchors which are applied to resist corrosion.