摘要
首先考虑围岩松动圈支护体的影响,在完全接触条件下,根据弹塑性力学理论,推导出深埋圆形隧道每层衬砌切向应力和径向应力分量的解析解;然后根据混凝土和围岩材料受力状态的不同,选用不同的破坏准则,引入功能梯度材料思想,构建了不同弹性模量双层混凝土圆形衬砌优化设计的目标函数,即当目标函数为最小值时,Ⅰ、Ⅱ和Ⅲ层结构同时接近或达到预设破坏状态,在设计上才最为合理;最后对衬砌材料的弹性模量和衬砌厚度分别进行了优化设计.算例分析表明:(1)随着围岩应力的增大,E2/E1和E2/E3都减小.在相同大小的围岩应力作用下,总有E2/E1<E2/E3,故而建议设计时Ⅰ层衬砌的弹性模量应大于围岩松动圈支护体的弹性模量.(2)随着围岩应力的增大,Ⅰ层衬砌的厚度增大.在相同大小的围岩应力作用下,当E2/E1>E2/E3时所求得的Ⅰ层衬砌最优厚度总是小于E2/E1<E2/E3时所求得的Ⅰ层衬砌厚度,故而可通过改变Ⅰ层衬砌和围岩松动圈支护体的弹性模量相对大小来调整Ⅰ、Ⅱ层衬砌的厚度.
Considering the broken rock zone support,tangential and radial stress component analytical solutions of each layer in full contact conditions are deduced in a deep circular tunnel based on the elastoplastic theory. Then an optimization objective function of circular concrete lining layers with different elastic moduli is constructed by choosing different failure criteria and different stress states of concrete and rock materials and by introducing the idea of functionally graded materials,that is,when the objective function is minimum,the most reasonable design is that the Ⅰ,Ⅱ and Ⅲ layer structures destroy at the same time. Finally,the elastic modulus and thickness of the lining is designed separately. The analysis of examples shows the following.（ 1） With the increase of surrounding rock stress,E2/ E1 and E2/ E3 both decrease. Under the same stress,there is always E2/ E1 E2/ E3,therefore it is suggested that the elastic modulus of the Ⅰ layer should be greater than the broken rock zone supporting＇s.（ 2） With the increase of surrounding rock stress,the thickness of the Ⅰ layer increases. Under the same stress,when E2/ E1 E2/ E3,the thickness of the Ⅰ layer is always less than that obtained when E2/ E1 E2/ E3,therefore the thicknesses of the Ⅰ and Ⅱ layers can be adjusted by changing the elastic moduli of the Ⅰ layer and the broken rock zone support.
出处
《工程科学学报》
EI
CAS
CSCD
北大核心
2015年第7期839-843,共5页
Chinese Journal of Engineering
基金
科技北京百名领军人才培养工程(Z151100000315014)
国家自然科学基金资助项目(51074014
51174014)
关键词
隧道
支护体
衬砌
弹性模量
厚度
优化设计
tunnels
supports
lining
elastic modulus
thickness
optimization design
