坑道口部管棚加固抗爆性能模型试验研究  

Model experiments on anti-detonating performance of tunnel entrance using pipe roof reinforcement

作　　者：许宏发[1] 佟佺[1] 王广建 王德荣[1] 

机构地区：[1]解放军理工大学国防工程学院 [2]解放军72464部队

出　　处：《岩土力学》2012年第11期3219-3224,共6页Rock and Soil Mechanics

基　　金：国家973计划(No.2009CB724608);国家自然科学创新研究群体基金(No.51021001);国家杰出青年科学基金(No.50825402)

摘　　要：正确评估管棚加固围岩的抗爆性能,对坑道口部防护设计十分重要。基于相似模拟理论,用不同配比的水泥土替代自然岩体和注浆岩体,用塑料管替代钢管,模拟管棚超前支护坑道口部在爆炸荷载作用下的抗爆性能。制作了口部相似模型3件,模型长×宽×高为2 m×2.2 m×2 m,在顶部直接爆炸,分别模拟无管棚、1层管棚和3层管棚下,坑道口部动力响应和破坏特征。试验表明:管棚超前支护能有效加固坑道围岩,整体性增强,受力分布合理;随着管棚层数增加,口部破坏明显减弱,拱顶破坏范围从1.55 m减小到0.45 m、主裂缝最大宽度由25 mm减小到3 mm、网状裂缝最大宽度由24 mm减小到0.3 mm、裂缝条数由14条减少到3条、模型顶部爆坑体积由0.12 m3减小到0.05 m3。管棚超前支护能有效地将爆炸荷载的破坏作用控制在管棚加固层之外,抗打击能力明显增强。It is very important for protective design of tunnel entrance that assessing anti-detonating performance of surrounding rock using pipe roof reinforcement. Based on principle of similarity simulation, nature or grouting rockrnass and steel pipe were replaced using cement soil of different cement-mixing ratios and plastic pipe respectively. Using the model tests, anti-detonating performance of tunnel entrance reinforced with pipe roof under explosive load was simulated. Length, width and height of three models are 2 m, 2.2 m and 2 m respectively. The dynamic response and failure characteristic on tunnel entrance reinforced with none, one layer and three layers pipe roof were simulated using the three models respectively under direct explosion in the model top. Experiments show that the pipe roof supporting can reinforce surrounding rock effectively, enhance integrity and make the distributions of stress more reasonable; the entrance failure decreases significantly with the increase of pipe roof layer, such as failure range from 1.55 m to 0.45 m, the maximum main crack width from 25 mm to 3 mm, the maximum netty crack width from 24 mm to 0.3 mm, the crack number from 14 to 3 in the arch crown of tunnel, and the blasting pit volume from 0.12 m3 to 0.05 m3 in the mode/top. The pipe roof advance support can control effectively explosion damage outside the pipe roof reinforced layer.

关 键 词：坑道口部 管棚支护 模型试验 抗爆性能 

分 类 号：TU93[建筑科学—结构工程]