顶爆下锚固硐室拱顶变形与加速度响应模型试验  

Model test on deformation and acceleration response of anchorage tunnels’ arch vaults under top explosion

作　　者：杨自友 杨本水 顾金才[2] YANG Ziyou;YANG Benshui;GU Jincai(School of Civil Engineering,Anhui Jianzhu University,Hefei 230601,China;The Third Research Institute of the Corps of Engineering,General Staff of PLA,Luoyang 471023,China)

机构地区：[1]安徽建筑大学土木工程学院,安徽合肥230601 [2]总参工程兵科研三所,河南洛阳471023

出　　处：《煤炭学报》2020年第2期590-597,共8页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51674005,51774007);安徽省高校自然科学基金重点资助项目(KJ2018A0501)

摘　　要：若地下硐室拱顶的变形或加速度过大,其围岩就会因此而破坏或不稳定。为了探索锚固硐室拱顶变形与加速度对爆炸荷载的响应规律,开展了室内顶爆模型试验研究。根据Froude相似原理,对顶爆试验进行了设计,对开挖硐室围岩采用不同锚固参数锚杆进行了加固。通过测定硐室拱顶变形与加速度波形曲线及其峰值,比较了不同锚固参数硐室拱顶变形、加速度及其最终破坏形态特征的差异性。结果表明,在爆炸荷载作用下,当硐室拱顶的环向应变、加速度波形处于正峰值时,拱顶曲率减小,围岩产生拉伸变形;锚杆间距比其长度对硐室拱顶变形的影响大;当锚杆的长度增大到一定程度时,对拱顶变形和加速度减小的作用并不明显,反而增大了拱顶加速度;当锚杆长度相同时,疏锚杆硐室拱顶出现了下沉、纵横向裂缝和掉块;当锚杆间距相同时,短密锚杆硐室拱顶仅出现了裂缝,但偏离了纵向方向,而长密锚杆硐室拱顶的变形相对较小,仅产生纵向直裂缝;拱脚加长硐室拱顶的变形比疏锚杆硐室小一个数量级,且其拱顶加速度相对较小,故采用这种加固方式有利于维护拱顶稳定。综合比较变形、加速度对硐室拱顶稳定性的影响发现,前者大小能在一定程度上可以作为判定影响拱顶稳定性的关键指标,而后者只能视作辅助性指标。If the deformation or acceleration of arch vault is too large,the surrounding rock of underground cavern will be damaged or unstable.In order to investigate the response regularities of arch vault’s deformation and ac-celeration to the explosion loads,the indoor top explosion model tests have been carried out.According to the principle of Froude similarity,the model tests are designed,and the surrounding rock of the excavation cavern has been strengthened by rockbolts with different anchorage parameters.The differences of deformation,acceleration and final damage morphological characteristics of arch vaults of the caverns with different anchorage parameters are compared through the measured wave curves and peak values of the deformation and acceleration of arch vaults.The results show that when the hoop strain and acceleration waveform curves of arch vaults are at the positive peak under explosive loads,the curvature decreases and the surrounding rocks of arch vaults are subjected to tensile deformation.The intervals between rockbolts have a greater effect on the deformation of arch vaults than their lengths.When the lengths of rockbolts increase to a certain extent,the deformation and acceleration of arch vaults are not obviously reduced,but increased contrarily.When the lengths of rockbolts are the same,the arch vaults of the sparse anchorage caverns shows sink,longitudinal and transverse cracks and falling blocks.When the intervals of rockbolts are the same,cracks only appear on the arch vaults of the short and dense anchorage caverns,but deviate from the longitudinal direction,while the deformations are relatively small and only produces longitudinal straight cracks of the arch vaults of the long and dense anchorage caverns.The deformation of the arch vault of the cavern which elongates arch foot’s rockbolts is one order of magnitude smaller than that of a sparse anchorage cavern,and its arch vault’s acceleration is relatively small.Therefore,this reinforcement method is helpful to maintain the stabilit

关 键 词：锚固硐室 模型试验 顶爆 拱顶 加速度 

分 类 号：TU457[建筑科学—岩土工程]