砂土-高密度海绵垫层棚洞力学特性研究  

Mechanical Characteristics of Sand High-Density Sponge Cushion in Shed Tunnel

作　　者：王星 王帅帅 黄帅 梅华[4] 胡朝霞 WANG Xing;WANG Shuaishuai;HUANG Shuai;MEI Hua;HU Zhaoxia(School of Highway Chang'an University,Xi'an 710064,Shaanxi,China;CCCC Second Highway Engineering CO.,Ltd.,Xi'an 710065,Shaanxi,China;Research and Development Center on Construction Technology of Long Bridge&Tunnel in Mountain Area,CCCC,Xi'an 710199,Shaanxi,China;School of Civil and Architecture Engineering,Hunan Institute of Technology,Hengyang 421002,Hunan,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]中交第二公路工程局有限公司,陕西西安710065 [3]中交集团山区长大桥隧建设技术研发中心,陕西西安710199 [4]湖南工学院土木与建筑工程学院,湖南衡阳421002

出　　处：《重庆交通大学学报（自然科学版）》2024年第6期16-24,共9页Journal of Chongqing Jiaotong University(Natural Science)

基　　金：湖南省教育厅科学研究项目(22C0616);湖南省大学生创新训练计划项目(S202211528045)。

摘　　要：依托某隧道洞口工程,探究更为有效的落石冲击防护结构,采用1∶10几何相似模型试验与LS-DYNA数值计算方法,揭示落石冲击作用下砂土-高密度海绵复合垫层力学响应机理。模型试验结果表明:添加3、6 cm高密度海绵构成复合垫层,顶板腹部中心应力峰值由1.71 MPa依次下降至0.75、0.24 MPa,降幅为55.90%、86.43%。与试验等比数值计算结果表明:添加3、6 cm海绵构成复合垫层,顶板腹部中心应力峰值由1.13 MPa降至0.57、0.22 MPa,降幅可达49.73%、80.35%。实际工况数值计算结果表明:复合垫层棚洞应力水平大幅降低,板内应力整体较均匀且中心位置应力集中状态已基本消除,应力曲线已由纯砂土垫层的折线形式变化为波浪式,应力峰值由5.63 MPa降至1.77 MPa,降幅可达68.56%。位移峰值由-3.08 mm降至-2.51 mm,加速度峰值由514 m/s 2降至445 m/s 2。Based on a tunnel entrance project,more effective rockfall impact protection structures were explored.A 1∶10 geometric similarity model test and LS-DYNA numerical calculation method were used to reveal the mechanical response mechanism of sand high-density sponge composite cushion under rockfall impact.The model test results show that the peak stress at the center of the roof belly decreases from 1.71 MPa to 0.75,0.24 MPa with the addition of 3 and 6 cm high-density sponge to form the composite cushion,and the decrease is 55.90%and 86.43%.The results of numerical calculation equally proportional to the test show that after adding 3 and 6 cm sponges to form a composite cushion layer,the peak stress at the center of the roof belly decreases from 1.13 MPa to 0.57 and 0.22 MPa,with a decrease of 49.73%and 80.35%.The numerical calculation results of actual working conditions indicate that the stress level of the shed tunnel with composite cushion is significantly reduced,the overall stress inside the board is relatively uniform,and the stress concentration state at the center has been basically eliminated.The stress curve has changed from a broken line form of pure sand cushion to a wave like pattern,with the peak stress decreasing from 5.63 MPa to 1.77 MPa and with a reduction of up to 68.56%.The peak displacement decreases from-3.08 mm to-2.51 mm and the peak acceleration decreases from 514 m/s 2 to 445 m/s 2.

关 键 词：隧道工程 落石冲击 防护结构 砂土-海绵垫层 模型试验 LS-DYNA 

分 类 号：U451[建筑科学—桥梁与隧道工程]