STUDY ON SHAKING TABLE TEST OF FREESTANDING STONE CAVE DWELLING
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摘要: 根据现场调研,以山西省静乐县典型三连拱独立式石箍窑洞为研究对象,设计制作了缩尺比例为1∶4的模型结构,并对其进行了地震模拟振动台试验,分析了模型结构的自振频率、阻尼比、加速度放大系数、最大相对位移、位移角、底部剪力与耗能等。结果表明:独立式石箍窑洞结构在地震作用下的薄弱部位为边洞洞口处拱顶与中窑腿;随着输入地震波峰值加速度的增大,模型结构自振频率下降,阻尼比上升;模型结构各部位的动力放大系数随着输入峰值加速度的增加变化不大, x向动力放大系数最大处为拱顶,y向动力放大系数最大处为窑顶;输入加速度峰值为70 gal(小震)、200 gal(中震)、440 gal(大震)时,结构最大侧移角均出现在拱顶,分别为1/1618、1/491、1/255,输入峰值加速度为600 gal时,最大侧移角出现在窑顶,为1/102;输入峰值加速度为800 gal时,结构的最大扭转角为0.0037 rad;底部剪力和累积滞回耗能均随着输入地震波峰值加速度的增大而增大。研究结果可为石箍窑洞这一西北传统民居的妥善保护和传承提供科学依据。Abstract: According to the on-site investigation, taking the typical three-arch freestanding stone cave dwelling in Jingle County, Shanxi Province as the research object, the paper designed and manufactured a 1/4 model, and then carried out a shaking table test for it. The natural vibration frequency, damping ratio, acceleration amplification factor, maximum relative displacement, lateral displacement angle, base shear force and structural energy dissipation were analyzed. Test results show that the weak parts under the earthquake action are the dome and the middle kiln leg at the entrance of the side cave. With the increase of the peak acceleration of input seismic wave, the natural vibration frequency of the model decreases and the damping ratio increases. The dynamic amplification coefficients of the model changes little with the increase of the input peak acceleration. The largest dynamic amplification coefficient in the x-direction and y-direction occurs at the arch roof and kiln roof, respectively. When the input peak acceleration is 70 gal (frequent earthquakes), 200 gal (fortification earthquakes) and 440 gal (rare earthquakes), the maximum lateral displacement angle of the model occurs in the arch roof, which is 1/1618, 1/491 and 1/255, respectively. When the input peak acceleration is 600 gal, the maximum lateral displacement angle occurs in the kiln roof, which is 1/102. When the input peak acceleration is 800 gal, the maximum torsion angle of the model is 0.0037 rad. The bottom shear force and energy dissipation of the model increase with the increase of the peak acceleration of input seismic wave.
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表 1 模型参数相似关系
Table 1. Similarity of model parameters
物理量 相似关系 物理量 相似关系 长度 1/4 质量 1/32 位移 1/4 时间 ${\text{1}}:2\sqrt 2 $ 应力 1 加速度 2 弹性模量 1 频率 $2\sqrt 2 :1$ 密度 2 阻尼 $1:16\sqrt 2 $ 表 2 黄土的动力特性
Table 2. Dynamic properties of loess
密度
ρ/(g/cm3)干密度
ρd/(g/cm3)含水率
ω/(%)初始动弹性模量
Ed0/(kg/cm2)阻尼比
ξ固结应力比
Kc破坏振次
Nf围压
σ3/kPa破坏动应力
σdf/kPa动粘聚力
Cd/kPa动摩擦角
φ/(º)1.78 1.63 11.6 2358.41 0.087~0.131 4.5 10 90 373.46 88.42 40.69 100 393.99 110 410.95 20 90 373.17 88.12 100 393.12 110 409.93 30 90 372.57 87.94 100 392.25 110 408.91 表 3 试验加载工况
Table 3. Testing loading cases
序号 工况编号 输入峰值加速度${a_{pg}}/g$ 地震
水准x向 y向 z向 1 B1 − − − − 2/3/4 Ex1/Lx1/Rx1 0.07 − − 7度
多遇5/6/7 Exy1/Lxy1/Rxy1 0.07 0.060 − 8/9/10 Exyz1/Lxyz1/Rxyz1 0.07 0.060 0.046 11 B2 − − − − 12/13/14 Ex2/Lx2/Rx2 0.14 − − 8度
多遇15/16/17 Exy2/Lxy2/Rxy2 0.14 0.119 − 18/19/20 Exyz2/Lxyz2/Rxyz2 0.14 0.119 0.091 21 B3 − − − − 22/23/24 Ex3/Lx3/Rx3 0.20 − − 7度
设防25/26/27 Exy3/Lxy3/Rxy3 0.20 0.170 − 28/29/30 Exyz3/Lxyz3/Rxyz3 0.20 0.170 0.130 31 B4 − − − − 32/33/34 Ex4/Lx4/Rx4 0.44 − − 7度
罕遇35/36/37 Exy4/Lxy4/Rxy4 0.44 0.370 − 38/39/40 Exyz4/Lxyz4/Rxyz4 0.44 0.370 0.290 41 B5 − − − − 42/43/44 Ex5/Lx5/Rx5 0.60 − − 8度
(0.3 g)
设防45/46/47 Exy5/Lxy5/Rxy5 0.60 0.510 − 48/49/50 Exyz5/Lxyz5/Rxyz5 0.60 0.510 0.390 51 B6 − − − − 52/53/54 Ex6/Lx6/Rx6 0.80 − − 9度
设防55/56/57 Exy6/Lxy6/Rxy6 0.80 0.680 − 58/59/60 Exyz6/Lxyz6/Rxyz6 0.80 0.680 0.520 61 B7 − − − − 62 Ex7 1.00 − − − 63 Exy7 1.00 0.850 − 64 Exyz7 1.00 0.850 0.650 65 B8 − − − − 66 Ex8 1.24 − − 9度
罕遇67 Exy8 1.24 1.050 − 68 Exyz8 1.24 1.050 0.810 69 B9 − − − − 注:x向为平行于窑脸方向;y向为沿窑洞进深方向。 表 4 模型结构自振频率与阻尼比
Table 4. Frequency and damping ratio of model structure
加载阶段 x向 y向 频率/Hz 阻尼比/(%) 频率/Hz 阻尼比/(%) 震前(B1) 18.36 1.34 15.04 4.97 输入0.07 g(B2) 17.97 1.44 14.84 7.32 输入0.14 g(B3) 17.96 1.64 14.55 7.69 输入0.28 g(B4) 16.99 1.75 14.00 8.45 输入0.44 g(B5) 15.53 2.60 13.96 9.77 输入0.60 g(B6) 14.45 2.73 13.96 9.80 输入0.80 g(B7) 12.01 4.30 12.69 9.22 输入1.00 g(B8) 9.08 6.30 10.54 9.34 表 5 台面加速度和基础顶面加速度对比
Table 5. Comparison of acceleration between platform and foundation
输入加速度峰值/g x向(m/s2) y向(m/s2) 台面 基础顶面 比值 台面 基础顶面 比值 0.07 0.672 0.673 0.999 0.583 0.585 0.997 0.14 1.375 1.373 1.001 1.163 1.166 0.997 0.28 2.752 2.755 0.999 2.335 2.334 1.000 0.44 4.321 4.326 0.999 3.668 3.669 1.000 0.60 5.789 5.788 1.000 4.994 4.996 1.000 0.80 7.852 7.852 1.000 6.669 6.667 1.000 1.00 9.796 9.801 0.999 8.336 8.339 1.000 -
[1] 杨柳, 刘加平. 黄土高原窑洞民居的传承与再生[J]. 建筑遗产, 2021, 6(2): 22 − 31.YANG Liu, LIU Jiaping. Inheritance and renewal of traditional yaodong dwellings on the loess plateau [J]. Heritage Architecture, 2021, 6(2): 22 − 31. (in Chinese) [2] HU S, QIU H J, WANG N L, et al. The influence of loess cave development upon landslides and geomorphologic evolution: A case study from the northwest Loess Plateau, China [J]. Geomorphology, 2020, 359: 107167. doi: 10.1016/j.geomorph.2020.107167 [3] 闫月梅. 石砌窑洞拱圈的受力分析和截面计算[C]. 海口: 第五届全国结构工程学术会议论文集(I), 1996: 672 − 675.YAN Yuemei. Stress analysis and section calculation of arch ring in stone cave [C]. Haikou: Proceedings of the 5th National Academic Conference on Structural Engineering (I), 1996: 672 − 675. (in Chinese) [4] 闫月梅, 郭秉山. 石砌窑洞合理拱圈的研究[C]. 泉州: 第四届全国结构工程学术会议论文集(II), 1995: 655 − 658.YAN Yuemei, GUO Bingshan. Study on reasonable arch ring of stone cave [C]. Quanzhou: Proceedings of the 4th National Academic Conference on Structural Engineering (II), 1995: 655 − 658. (in Chinese) [5] 王崇恩, 李媛昕, 朱向东, 等. 店头村石碹窑洞建筑结构分析[J]. 太原理工大学学报, 2014, 45(5): 638 − 642. doi: 10.3969/j.issn.1007-9432.2014.05.014WANG Chongen, LI Yuanxin, ZHU Xiangdong, et al. Analysis on building structure of stone arch cave houses in dian tou county [J]. Journal of Taiyuan University of Technology, 2014, 45(5): 638 − 642. (in Chinese) doi: 10.3969/j.issn.1007-9432.2014.05.014 [6] 郭平功, 童丽萍. 横向地震对黄土窑洞稳定性的影响[J]. 地震工程与工程振动, 2015, 35(6): 56 − 63.GUO Pinggong, TONG Liping. Influence of crosswise earthquake on loess cave dwellings, stability [J]. Earthquake Engineering and Engineering Vibration, 2015, 35(6): 56 − 63. (in Chinese) [7] 王飞剑, 刘如山, 马朝晖. 窑洞外形特征对结构抗震性能影响研究[J]. 地震工程学报, 2018, 40(5): 910 − 918. doi: 10.3969/j.issn.1000-0844.2018.05.910WANG Feijian, LIU Rushan, MA Zhaohui. Effect of cave dwelling shape on the seismic performance of structures [J]. China Earthquake Engineering Journal, 2018, 40(5): 910 − 918. (in Chinese) doi: 10.3969/j.issn.1000-0844.2018.05.910 [8] 薛建阳, 赵湘璧, 张风亮, 等. 下沉式黄土窑洞结构模型振动台试验研究[J]. 建筑结构学报, 2021, 42(3): 14 − 23.XUE Jianyang, ZHAO Xiangbi, ZHANG Fengliang, et al. Shaking table test on model structure of underground loess cave [J]. Journal of Building Structures, 2021, 42(3): 14 − 23. (in Chinese) [9] XUE J Y, HU P C, ZHANG F L, et al. Seismic behavior of brick cave dwellings: shake table tests [J]. Journal of Building Engineering, 2021, 43: 102886. doi: 10.1016/j.jobe.2021.102886 [10] 周颖, 吕西林. 建筑结构振动台模型试验方法与技术[M]. 北京: 科学出版社, 2016.ZHOU Ying, LYU Xilin. Method and technology for shaking table model test of building structures [M]. Beijing: Science Press, 2016. (in Chinese) [11] 薛建阳, 张风亮, 赵鸿铁, 等. 碳纤维布加固古建筑木结构模型振动台试验研究[J]. 土木工程学报, 2012, 45(11): 95 − 104.XUE Jianyang, ZHANG Fengliang, ZHAO Hongtie, et al. Shaking table test of ancient timber structure strengthened with CFRP [J]. China Civil Engineering Journal, 2012, 45(11): 95 − 104. (in Chinese) [12] DOWDEN D M, BRUNEAU M. Shake table testing of perforated steel plate shear wall having light gauge bolted infill panels [J]. Journal of Constructional Steel Research, 2022, 188: 107030. doi: 10.1016/j.jcsr.2021.107030 [13] 迟世春, 林少书. 结构动力模型试验相似理论及其验证[J]. 世界地震工程, 2004, 20(4): 11 − 12. doi: 10.3969/j.issn.1007-6069.2004.04.002CHI Shichun, LIN Shaoshu. Validation of similitude laws for dynamic structural model test [J]. World Earthquake Engineering, 2004, 20(4): 11 − 12. (in Chinese) doi: 10.3969/j.issn.1007-6069.2004.04.002 [14] 熊仲明, 陈轩, 王赟, 等. 跨地裂缝带支撑RC框架结构振动台试验研究[J]. 工程力学, 2019, 36(10): 86 − 95. doi: 10.6052/j.issn.1000-4750.2018.09.0483XIONG Zhongming, CHEN Xuan, WANG Yun, et al. Research on shaking table test of frame structure crossing the ground fissure with braces [J]. Engineering Mechanics, 2019, 36(10): 86 − 95. (in Chinese) doi: 10.6052/j.issn.1000-4750.2018.09.0483 [15] 王爱国, 杨晓鹏, 李明永, 等. 汶川Ms8.0地震对甘肃陇东地区的破坏影响与特征分析[J]. 西北地震学报, 2009, 31(1): 80 − 85.WANG Aiguo, YANG Xiaopeng, LI Mingyong, et al. The influence and characteristics of seismic damage in Longdong area of Gansu province in Wenchuan Ms 8.0 earthquake [J]. Northwestern seismological Journal, 2009, 31(1): 80 − 85. (in Chinese) [16] 王源, 王天琦, 孙利民, 等. 带消能连梁的矩形空心双柱式高墩抗震性能试验研究[J]. 工程力学, 2020, 37(7): 159 − 167. doi: 10.6052/j.issn.1000-4750.2019.08.0496WANG Yuan, WANG Tianqi, SUN Limin, et al. Experimental investigation on seismic performance of rectangular- hollow double-column tall piers with energy dissipation beams [J]. Engineering Mechanics, 2020, 37(7): 159 − 167. (in Chinese) doi: 10.6052/j.issn.1000-4750.2019.08.0496 [17] 张晋. 采用MATLAB进行振动台试验数据的处理[J]. 工业建筑, 2002, 32(2): 28 − 30, 65. doi: 10.3321/j.issn:1000-8993.2002.02.009ZHANG Jin. Using matlab to deal with data of the shaking table test [J]. Industrial Construction, 2002, 32(2): 28 − 30, 65. (in Chinese) doi: 10.3321/j.issn:1000-8993.2002.02.009 [18] 孙魁, 程绍革, 朱毅秀. 既有混凝土框架结构振动台试验动力特性及加速度响应[J]. 工程力学, 2020, 37(6): 229 − 236. doi: 10.6052/j.issn.1000-4750.2019.04.S043SUN Kui, CHENG Shaoge, ZHU Yixiu. Dynamic property and acceleration response of shaking table test about existing RC frame structures [J]. Engineering Mechanics, 2020, 37(6): 229 − 236. (in Chinese) doi: 10.6052/j.issn.1000-4750.2019.04.S043 -