研究目的:为了提高隧道围岩注浆加固效应的数值模拟方法的准确度和计算精度,研究了模拟注浆加固的常规有限元方法的误差,并通过有限元理论分析了该误差产生的原因,进而提出了模拟加固效应的改进方法。研究结论:(1)模拟注浆加固的常规有限元方法在多荷载步计算中,上一荷载步结点位移(应变)的存在会导致改变围岩加固区单元的材料参数的过程中产生结点力(即异常荷载),导致体系出现由于模拟方法不当引起不容忽视的计算误差;(2)提出了两种模拟加固效应的改进方法(旨在消除加固区单元初始应变):一种是在围岩加固区的单元上附加新单元的方法,另一种是消除上一计算步应变场,仅保留应力场后,直接改变加固区围岩参数的方法;(3)注浆加固模型试验结果验证了改进的数值模拟方法的合理性;(4)本研究成果可应用于隧道及其他岩土工程加固效应的数值模拟计算,提高计算精度。
Research purposes: For improving the accuracy and calculating precision of simulation method for the reinforcing measure in tunnel construction, the calculation error caused by routine method was studied. The reason for the calculation error was analyzed by finite element theory. And then two improved methods were brought up. Research conclusions: (1) For the nodal displacement or strain in last load step, improving element's parameters directly in reinforcing area makes nodes' internal load increasing in the load step, which will arouse false results. (2) Two improved methods are taken to simulate the reinforcing measure. The one is that a layer of elements are adhered to each element in the reinforcing area to simulate the reinforcement, the another is that improving surrounding rocks parameters after relieving the strains field and retaining the stress field of last step. (3)The improved methods to simulate the reinforcing measure are verified by model test. (4)The improved methods in this paper can improve the calculating precision for the reinforcing measure simulation in tunnel engineering and geotechnical engineering.