EPS板对综合管廊受力特性影响研究

Study on Influence of EPS Board on Mechanical Characteristics of Utility Tunnel

为保护综合管廊防水层,回填过程中管廊侧墙将放置1层EPS板,然而EPS板可能改变墙后土压力值从而影响结构受力。为了研究EPS板的存在对综合管廊受力特性的影响,以雄安新区雄东管廊项目为背景,采用验证后的数值模拟方法研究了管廊基坑开挖受力变形特性及EPS板对综合管廊土压力、变形和弯矩的影响。结果表明:管廊基坑开挖引发边坡位移与周围地表沉降,本文条件下边坡最大水平位移值约为0.23%H(H为基坑开挖深度),周围地表沉降值约为0.24%H。EPS板的放置将引发管廊墙后土压力、变形、弯矩发生改变。放置EPS板后综合管廊侧墙中性点以上土压力增大10.6%,中性点以下减小5.6%,最大侧墙水平变形值增加44.4%,结构最大弯矩值增大5.4%。

In order to protect the waterproof layer of the utility tunnel,a layer of EPS board will be placed on the side wall of the utility tunnel during backfilling.However,the existence of EPS board may change the earth pressure behind the wall and affect the stress of the structure.In order to study the influence of EPS board on the mechanical characteristics of the utility tunnel,taking the Xiongdong utility tunnel project in Xiongan New Area as the background,the mechanical deformation characteristics of the utility tunnel foundation excavation and the influence of EPS board on the earth pressure,deformation and bending moment of the comprehensive pipe gallery are studied by numerical simulation method.The results show that:the excavation of utility tunnel foundation excavation leads to slope displacement and surrounding surface settlement.Under this condition,the maximum horizontal displacement of slope is about 0.23%H(excavation depth of foundation excavation),and the surrounding surface settlement is about 0.24%H.The placement of EPS plate will change the earth pressure,deformation and bending moment behind the utility tunnel wall.After EPS is placed,the earth pressure above the neutral point of the side wall of the utility tunnle increases by 10.6%,decreases below the neutral point by 5.6%,the maximum horizontal deformation value of the side wall increases by 44.4%,and the maximum bending moment value of the structure increases by 5.4%.