摘要
软硬互层岩体的受力较为复杂,预制不同软硬互层厚度比的互层围岩隧道试件,通过试验研究互层围岩隧道周围的变形破坏特征,并采用数值模拟对互层围岩隧道周围的应力、应变分布进行分析对比。结果表明:当相对较软层较厚时,隧道的破坏受相对较软层压缩的影响更大,隧道轴向压缩变形量较大;当相对较硬层较厚时,隧道的破坏受相对较硬层岩层断裂的影响更大;当互层厚度均较薄时,更薄的岩层使隧道周围岩体的变形破坏更为连续。具体表现为:(1)相对较硬层10 mm且相对较软层10 mm工况下的试件整体破坏模式为强孔洞破坏模式,拱顶和拱底处张拉破坏较为严重,易在拱肩和拱脚处出现压-剪切复合型裂缝;(2)相对较硬层10 mm且相对较软层20 mm工况下的试件整体破坏模式为强压缩破坏模式,压剪破坏在拱腰表现明显,易在拱肩和拱脚处出现压-剪切复合型裂缝;(3)相对较硬层20 mm且相对较软层10 mm工况下的试件整体破坏模式为断裂破坏模式,拱顶下沉明显,拱腰附近应力水平较高,但破坏程度较小。
The stress of soft and hard interbedded mass is complex.Therefore,pre-fabricated specimens of interbedded surrounding rock tunnel in different thickness ratio of soft and hard interbedded mass were prefabricated to study the deformation and failure characteristics around the interbedded rock tunnel through experiments.The stress and strain distribution around the interbedded rock tunnel were analyzed and compared by numerical simulation.The results show that:When the relatively soft layer is thick,the damage of the tunnel is more affected by the compression of the relatively soft layer,and the axial compression deformation of the tunnel is larger.When the relatively hard layer is thick,the damage of the tunnel is more affected by the fracture of the relatively hard layer.When the interlayer thickness is thin,the thinner rock layer makes the deformation and failure of rock mass around the tunnel more continuous.(1)The overall failure mode of the test specimen under the condition of 10 mm relatively hard layer and 10 mm relatively soft layer is strong hole failure mode,in which the tensile failure is more serious at the vault and arch bottom,and pressure-shear composite crack is easily occurs at the arch shoulder and arch foot.(2)The overall failure mode of the test specimen under the condition of 10 mm relatively hard layer and 20 mm relatively soft layer is strong compression failure mode,in which the compression-shear failure is obvious at the arch waist,and the compression-shear composite crack is easily occurs at the arch shoulder and arch foot.(3)The overall failure mode of the test specimen under the condition of 20 mm relatively hard layer and 10mm relatively soft layer is fracture failure mode,in which the vault obviously sinks,and the stress level near the arch waist is high,but the failure degree of the arch waist is small.
作者
范祥
洪铭
Fan Xiang;Hong Ming(School of Highway,Chang'an University,Xi'an 710064,P.R.China;China Three Gorges Construction Engineering Corporation,Chengdu 610094,P.R.China)
出处
《地下空间与工程学报》
北大核心
2025年第6期2026-2039,共14页
Chinese Journal of Underground Space and Engineering
基金
陕西省自然科学基础研究计划资助项目(2022JM-160)。
关键词
软硬互层岩体
大跨度隧道
互层厚度比
双轴压缩
soft-hard interbedded mass
long-span tunnel
thickness ratio
biaxial compression
