Construction of CPT-based Liquefaction Database from 2003 Bachu Earthquake
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摘要: 2003年2月24日新疆巴楚—伽师地区发生MS6.8地震,出现了唐山地震、海城地震后近30年我国大陆最具规模的砂土液化现象。大量研究显示,巴楚地震液化砂土标贯击数与锥尖阻力指标偏大,采用国内外液化判别方法往往会判为非液化。利用Robertson土质分类图对巴楚地区孔压静力触探试验(CPTU)数据进行土类分层检验,基于以下原则,选定了液化点液化层与非液化点临界液化层。(1)应选取非液化点土层剖面中最易液化层,不能因液化点力学指标偏大而将非液化点临界液化层力学指标选得更大;(2)应结合qc-h与Rf-h图,避免选取黏土为液化层;(3)巴楚地区液化层往往上覆非饱和细砂,形成透水边界,选取液化层时应舍弃存在透水边界的土层。最后,利用我国规范方法构建了巴楚地震静力触探(CPT)液化数据库,并进行了初步的判别分析。Abstract: There occurred a MS6.8 earthquake on Feb. 24, 2003 in Bachu-Jiashi area, Xinjiang, which caused the most widespread and severe liquefaction after 1975 Haicheng and 1976 Tangshan earthquake nearly 30 years in mainland of China. A large number of studies show that SPT blow count and CPT cone tip resistance of liquefied soil in Bachu earthquake are too large to liquefy. In this paper, soil behavior-type chart proposed by Robertson was used to test soil type from CPTU data in Bachu area, critical liquefaction soil layer were selected by following principle. (1) CPT index of non-liquefaction critical layer cannot be selected larger only because that of liquefaction layer are large, (2) combining qc-h and Rf-h map to avoid selecting clay as liquefaction layer, (3) liquefied layer in Bachu area are often covered by unsaturated fine sand, which would form a permeable boundary and critical layer should be moved down by one layer. Finally, using Chinese code methods, CPT-based liquefaction database of Bachu earthquake was constructed and liquefaction is judged preliminarily.
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Key words:
- Bachu earthquake /
- Liquefaction /
- CPT /
- Soil behavior-type chart /
- Database
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表 1 E-06测点CPTU分层结果
Table 1. CPTU soil layer classification result of site E-06
序号 分层深度/m qc/MPa fs/kPa Rf/% σv0/kPa σ′v0/kPa n Q F/% Ic ① 3.0~4.1 8.38 53.25 0.64 66.10 66.10 0.50 102.23 0.64 1.79 ② 4.1~5.1 14.35 71.54 0.50 85.70 77.86 0.50 161.69 0.50 1.56 ③ 5.1~6.3(临界) 7.81 35.35 0.46 106.29 87.67 0.50 82.25 0.46 1.79 ④ 6.3~9.0(临界) 10.83 51.92 0.48 142.92 105.19 0.50 104.23 0.49 1.71 ⑤ 9.0~9.7 3.79 16.83 0.61 174.91 120.52 0.50 32.90 0.47 2.15 ⑥ 9.7~12.0 10.73 45.56 0.45 203.13 134.04 0.50 90.95 0.43 1.74 ⑦ 12.0~14.5 15.66 87.52 0.60 248.29 155.68 0.50 123.53 0.57 1.69 表 2 E-06测点土层土类检验结果
Table 2. Soil layer inspection results of site E-06
序号 钻孔柱状图土类 Robertson土质分类图土类 ① 细砂(埋深3.4~5.7 m) 6纯净砂-粉砂(埋深3.0~4.1 m) ② 6纯净砂-粉砂(埋深4.1~5.1 m) ③ 细砂(埋深5.7~12.95 m) 6纯净砂-粉砂(埋深5.1~6.3 m) ④ 6纯净砂-粉砂(埋深6.3~9.0 m) ⑤ 5粉砂-砂质粉土(埋深9.0~9.7 m) ⑥ 6纯净砂-粉砂(埋深9.7~12.0 m) ⑦ 6纯净砂-粉砂(埋深12.0~14.5 m) 表 3 SY-05测点CPTU分层结果
Table 3. CPTU soil layer classification result of site SY-05
序号 分层深度/m qc/MPa fs/kPa Rf/% σv0/kPa σ′v0/kPa n Q F/% Ic ① 0.6~2.8 3.03 93.73 3.68 31.60 31.60 0.50 53.42 3.12 2.44 ② 2.8~4.18 12.49 103.22 0.83 64.93 64.93 0.50 154.20 0.83 1.72 ③ 4.18~6.86(液) 12.60 76.42 0.62 102.72 84.89 0.50 135.64 0.61 1.67 ④ 6.86~8.4 16.15 105.36 0.89 142.01 103.50 0.50 157.37 0.66 1.64 ⑤ 8.4~10.0 2.39 89.18 4.00 171.32 117.42 1.00 18.88 4.02 2.85 ⑥ 10.0~12.0 3.09 105.97 3.93 205.02 133.48 1.00 21.62 3.67 2.78 表 4 SY-05测点土层土类检验结果
Table 4. Soil layer inspection results of site SY-05
序号 钻孔柱状图土类 Robertson土质分类图土类 ① 粉质黏土(埋深0.6~2.8 m) 4黏质粉土-粉质黏土(埋深0.6~2.8 m) ② 细砂(埋深2.8~8.4 m) 6纯净砂-粉砂(埋深2.8~4.18 m) ③ 6纯净砂-粉砂(埋深4.18~6.86 m) ④ 6纯净砂-粉砂(埋深6.86~8.4 m) ⑤ 黏土(埋深8.4~10.0 m) 3粉质黏土-黏土(埋深8.4~10.0 m) ⑥ 4黏质粉土-粉质黏土(埋深10.0~12.0 m) 表 5 SY-17测点CPTU分层结果
Table 5. CPTU soil layer classification result of site SY-17
序号 分层深度/m qc/MPa fs/kPa Rf/% σv0/kPa σ′v0/kPa n Q F/% Ic ① 0.5~2.5 1.86 9.24 0.49 27.93 17.15 0.50 44.12 0.51 2.05 ② 2.5~4.5(液) 2.53 14.52 0.57 65.17 34.79 0.50 41.87 0.59 2.10 ③ 4.5~5.5 9.49 57.58 0.61 93.20 48.12 0.50 135.42 0.61 1.68 ④ 5.5~7.9 20.19 114.18 0.56 125.19 63.45 0.50 251.93 0.57 1.45 ⑤ 7.9~9.22 19.57 135.20 0.79 160.18 80.21 0.50 216.76 0.70 1.55 表 6 SY-17测点土层土类检验结果
Table 6. Soil layer inspection results of site SY-17
序号 钻孔柱状图土类 Robertson土质分类图土类 ① 细砂(埋深0~4.7 m) 6纯净砂-粉砂(埋深0.5~2.5 m) ② 5粉砂-砂质粉土(埋深2.5~4.5 m) ③ 细砂(埋深4.7~9.5 m) 6纯净砂-粉砂(埋深4.5~5.5 m) ④ 6纯净砂-粉砂(埋深5.5~7.9 m) ⑤ 6纯净砂-粉砂(埋深7.9~9.22 m) 表 7 ZK30测点CPTU分层结果
Table 7. CPTU soil layer classification result of site ZK30
序号 分层深度/m qc/MPa fs/kPa Rf/% σv0/kPa σ′v0/kPa n Q F/% Ic ① 1.6~2.6 1.42 29.78 2.31 38.95 38.95 0.70 26.77 2.15 2.57 ② 2.6~4.1(液) 4.09 44.61 1.14 62.22 54.87 0.50 54.38 1.11 2.15 ③ 4.1~6.8(液) 8.38 65.34 0.83 101.32 73.39 0.50 96.64 0.79 1.86 ④ 6.8~8.56 22.00 145.80 0.66 142.93 93.15 0.50 226.45 0.67 1.53 表 8 ZK30测点土层土类检验结果
Table 8. Soil layer inspection results of site ZK30
序号 钻孔柱状图土类 Robertson土质分类图土类 ① 粉质黏土(埋深1.2~3.0 m) 4黏质粉土-粉质黏土(埋深1.6~2.6 m) ② 细砂(埋深3.0~7.8 m) 5粉砂-砂质粉土(埋深2.6~4.1 m) ③ 6纯净砂-粉砂(埋深4.1~6.8 m) ④ 中砂(埋深7.8~14.3 m) 6纯净砂-粉砂(埋深6.8~8.56 m) 表 9 锥尖阻力基准值qc0
Table 9. Liquefied reference value of cone tip resistance
抗震设防烈度 Ⅶ度 Ⅷ度 Ⅸ度 qc0/MPa 4.6~5.5 10.5~11.8 16.4~18.2 表 10 土性修正系数αp
Table 10. Values of soil property correction factor αp
土类 砂土 粉土 摩阻比Rf/ % Rf≤0.4 0.4<Rf≤0.9 Rf>0.9 αp 1. 00 0.60 0.45 表 11 基于CPT测试的我国方法巴楚地震液化数据库(液化点)
Table 11. CPT-based liquefaction database from Bachu earthquake according to Chinese code methods (liquefaction spot)
测试点 地震烈度 土层范围/m σv0 /kPa σ′v0/kPa qc/MPa Rf/% qc0/MPa dw/m du/m αw αu αp qccr/MPa 是否液化 SY06 Ⅸ 3.2~5.6 82.79 68.09 6.63 0.76 16.85 2.9 3.2 0.94 0.94 0.60 8.95 是 SY07 Ⅸ 4.0~5.4 87.51 68.89 7.08 0.87 16.85 2.8 4.0 0.95 0.90 0.60 8.63 是 SY09 Ⅸ 3.8~5.46 86.57 58.84 8.96 0.64 16.85 1.8 3.8 1.01 0.91 0.60 9.32 是 SY12 Ⅸ 7.0~9.2 151.07 105.01 11.95 1.05 16.85 3.4 7.0 0.91 0.75 0.45 5.17 否 SY14-1 Ⅸ 4.4~5.6 93.35 62.97 3.16 0.66 16.85 1.9 4.4 1.01 0.88 0.60 8.95 是 SY14-2 Ⅸ 7.6~9.3 158.14 93.95 10.14 0.68 16.85 1.9 7.6 1.01 0.72 0.60 7.33 否 ZK30-1 Ⅸ 2.6~4.1 62.22 54.87 4.09 1.14 16.85 2.6 2.6 0.96 0.97 0.45 7.07 是 ZK30-2 Ⅸ 4.1~6.8 101.32 73.39 8.38 0.83 16.85 2.6 4.1 0.96 0.90 0.60 8.70 是 SY01 Ⅷ 2.9~4.0 62.24 58.85 1.55 0.96 10.83 2.9 2.9 0.94 0.96 0.45 4.38 是 SY08-1 Ⅷ 3.14~4.7 72.99 43.88 5.39 0.65 10.83 0.95 3.14 1.07 0.94 0.60 6.55 是 SY08-2 Ⅷ 4.7~8.7 124.75 68.4 6.96 0.8 10.83 0.95 4.7 1.07 0.87 0.60 6.00 否 SY11 Ⅷ 4.0~6.6 97.37 73.85 6.76 0.77 10.83 2.9 4.0 0.94 0.90 0.60 5.51 否 SY16 Ⅷ 3.0~4.8 72.32 57.62 8.82 0.87 10.83 2.4 3.0 0.97 0.95 0.60 6.01 否 SY17 Ⅷ 2.5~4.5 65.17 34.79 2.53 0.57 10.83 0.4 2.5 1.10 0.98 0.60 6.99 是 SY18-1 Ⅷ 5.5~6.8 114.51 87.56 6.30 0.48 10.83 3.4 5.5 0.91 0.83 0.60 4.87 否 SY18-2 Ⅷ 6.8~8.3 140.58 99.91 8.48 0.53 10.83 3.4 6.8 0.91 0.76 0.60 4.49 否 SY21 Ⅷ 3.8~5.0 81.93 67.23 5.18 0.90 10.83 2.9 3.8 0.94 0.91 0.60 5.57 是 SY25 Ⅷ 2.7~5.3 72.26 49.72 7.54 0.65 10.83 1.7 2.7 1.02 0.97 0.60 6.39 否 SY05 Ⅶ 4.18~6.86 102.72 84.89 12.60 0.62 4.83 3.7 4.18 0.89 0.89 0.60 2.29 否 SY19 Ⅶ 2.1~2.9 46.31 42.39 5.08 1.71 4.83 2.1 2.1 0.99 1.00 0.45 2.15 否 SY23 Ⅶ 4.0~5.8 91.33 65.85 5.80 0.55 4.83 2.3 4.0 0.98 0.90 0.60 2.55 否 SY24 Ⅶ 4.0~7.4 106.72 78.30 4.53 0.67 4.83 2.8 4.0 0.95 0.90 0.60 2.47 否 SY26-1 Ⅶ 3.0~4.7 71.10 57.87 8.00 0.7 4.83 2.5 3.0 0.97 0.95 0.60 2.66 否 SY26-2 Ⅶ 4.7~6.26 101.45 72.25 5.02 1.21 4.83 2.5 4.7 0.97 0.87 0.45 1.82 否 SY27-1 Ⅶ 1.66~2.8 41.09 23.64 3.29 0.54 4.83 0.45 1.66 1.10 1.02 0.60 3.24 否 SY27-2 Ⅶ 3.8~7.0 100.31 51.80 5.80 0.66 4.83 0.45 3.8 1.10 0.91 0.60 2.90 否 SY29 Ⅶ 5.8~6.9 118.48 94.47 10.44 0.88 4.83 3.9 5.8 0.88 0.81 0.60 2.06 否 表 12 基于CPT测试的我国方法巴楚地震液化数据库(非液化点)
Table 12. CPT-based liquefaction database from Bachu earthquake according to Chinese code methods (non-liquefaction spot)
测试点 地震烈度 土层
范围/mσv0
/kPaσ′v0/kPa qc/MPa Rf/% qc0/MPa dw/m du/m αw αu αp qccr/MPa 是否液化 E02 Ⅸ 6.8~8.2 140.8 104.54 12.81 1.21 16.85 3.8 6.8 0.88 0.76 0.45 5.09 否 E04-1 Ⅸ 3.3~4.2 69.88 63.51 9.59 0.81 16.85 3.1 3.3 0.93 0.94 0.6 8.78 否 E04-2 Ⅸ 5.0~6.24 105.07 80.37 9.84 1 16.85 3.1 5 0.93 0.85 0.45 5.98 否 E05 Ⅸ 6.5~9.2 146.43 101.84 13.87 0.65 16.85 3.3 6.5 0.92 0.78 0.6 7.17 否 ZK33 Ⅸ 4.5~5.5 93.59 68.11 9.23 0.83 16.85 2.4 4.5 0.97 0.88 0.6 8.62 否 ZK38 Ⅸ 3.1~4.2 67.56 56.29 10.9 0.74 16.85 2.5 3.1 0.97 0.95 0.6 9.24 否 ZK39 Ⅸ 4.4~6.0 96.49 71.5 13.21 0.56 16.85 2.65 4.4 0.96 0.88 0.6 8.52 否 E03-1 Ⅷ 5.2~6.0 104.27 71.93 13.33 0.66 10.83 2.3 5.2 0.98 0.84 0.6 5.35 否 E03-2 Ⅷ 6.0~8.0 130.34 84.28 15.78 0.58 10.83 2.3 6.0 0.98 0.80 0.6 5.10 否 E06-1 Ⅷ 5.1~6.3 106.29 87.67 7.81 0.46 10.83 3.8 5.1 0.88 0.85 0.6 4.85 否 E06-2 Ⅷ 6.3~9.0 142.92 105.19 10.83 0.48 10.83 3.8 6.3 0.88 0.79 0.6 4.50 否 E09-1 Ⅷ 4.0~5.1 84.92 68.75 3.95 1.17 10.83 2.9 4.0 0.94 0.90 0.45 4.13 是 E09-2 Ⅷ 5.1~6.8 111.21 81.32 7.08 1.02 10.83 2.9 5.1 0.94 0.85 0.45 3.88 否 E10-1 Ⅷ 3.84~5.8 89.28 63.60 1.62 2.11 10.83 2.2 3.84 0.99 0.91 0.45 4.37 是 E10-2 Ⅷ 7.8~9.5 160.49 97.28 11.8 0.54 10.83 2.2 7.8 0.99 0.71 0.6 4.55 否 E11 Ⅷ 2.3~5.7 74.09 46.65 6.84 0.59 10.83 1.2 2.3 1.05 0.99 0.6 6.73 否 ZK24 Ⅷ 4.5~6.0 97.76 74.73 9.13 0.49 10.83 2.9 4.5 0.94 0.88 0.6 5.35 否 ZK25 Ⅷ 5.5~7.5 120.93 73.89 9.08 0.57 10.83 1.7 5.5 1.02 0.83 0.6 5.47 否 E07 Ⅶ 3.86~7.3 100.94 73.69 8.03 0.51 4.83 2.8 3.86 0.95 0.91 0.6 2.49 否 E08 Ⅶ 4.2~5.3 88.55 83.16 16.27 0.43 4.83 4.2 4.2 0.86 0.89 0.6 2.21 否 E12 Ⅶ 5.9~7.5 123.16 82.98 10.88 0.67 4.83 2.6 5.9 0.96 0.81 0.6 2.24 否 E13 Ⅶ 4.4~5.5 92.26 70.21 11.54 0.58 4.83 2.7 4.4 0.95 0.88 0.6 2.43 否 -
艾买提•乃买提, 2004.2003年2月24日新疆巴楚—伽师MS6.8级地震加速度记录简介. 内陆地震, 18(3): 254—259Naimaiti A. , 2004. Brief introduction on acceleration record of Bachu-Jiashi MS6.8 earthquake in Xinjiang on Feb. 24, 2003. Inland Earthquake, 18(3): 254—259. (in Chinese) 董林, 2010. 新疆巴楚-伽师地震液化初步研究. 哈尔滨: 中国地震局工程力学研究所.Dong L. , 2010. Primary study on liquefaction in Bachu-Jiashi Earthquake. Harbin: Institute of Engineering Mechanics, China Earthquake Administration. (in Chinese) 国家铁路局, 2018. TB 10018—2018 铁路工程地质原位测试规程. 北京: 中国铁道出版社.National Railway Administration of the People's Republic of China, 2018. TB 10018—2018 Code for in-site testing of railway engineering geology. Beijing: China Railway Publishing House. (in Chinese) 李兆焱, 2012. 基于巴楚地震调查的液化判别方法研究. 哈尔滨: 中国地震局工程力学研究所.Li Z. Y. , 2012. A study into liquefaction discrimination methods based on surveys of the Bachu earthquake. Harbin: Institute of Engineering Mechanics, China Earthquake Administration. (in Chinese) 李兆焱, 袁晓铭, 曹振中等, 2012. 基于新疆巴楚地震调查的砂土液化判别新公式. 岩土工程学报, 34(3): 483—489Li Z. Y. , Yuan X. M. , Cao Z. Z. , et al. , 2012. New evaluation formula for sand liquefaction based on survey of Bachu Earthquake in Xinjiang. Chinese Journal of Geotechnical Engineering, 34(3): 483—489. (in Chinese) 李兆焱, 王永志, 袁晓铭, 2013 a. 适用于新疆巴楚地区的CPT液化判别新方法. 岩土工程学报, 35(S1): 140—145Li Z. Y. , Wang Y. Z. , Yuan X. M. , 2013 a. New CPT-based prediction method for soil liquefaction applicable to Bachu region of Xinjiang. Chinese Journal of Geotechnical Engineering, 35(S1): 140—145. (in Chinese) 李兆焱, 汪云龙, 曹振中等, 2013 b. 我国规范液化判别方法在新疆地区适用性检验. 岩土工程学报, 35(S2): 396—400Li Z. Y. , Wang Y. L. , Cao Z. Z. , et al. , 2013 b. Feasibility of liquefaction prediction method in China's seismic code to Xinjiang region. Chinese Journal of Geotechnical Engineering, 35(S2): 396—400. (in Chinese) 罗福忠, 胡伟华, 赵纯青等, 2006. 巴楚—伽师6.8级地震地质灾害及未来地震地质灾害. 内陆地震, 20(1): 33—39Luo F. Z. , Hu W. H. , Zhao C. Q. , et al. , 2006. Geological disaster of Bachu-Jiashi MS6.8 earthquake and geological disaster of future earthquake. Inland Earthquake, 20(1): 33—39. (in Chinese) 孟高头, 张德波, 刘事莲等, 2000. 推广孔压静力触探技术的意义. 岩土工程学报, 22(3): 314—318Meng G. T. , Zhang D. B. , Liu S. L. , et al. , 2000. The significance of piezocone penetration test. Chinese Journal of Geotechnical Engineering, 22(3): 314—318. (in Chinese) 王蕾, 董林, 夏坤等, 2021.1976年唐山大地震CPT液化数据库检验. 震灾防御技术, 16(4): 737—749Wang L. , Dong L. , Xia K. , et al. , 2021. Inspection on CPT-based liquefaction database from 1976 Tangshan Earthquake. Technology for Earthquake Disaster Prevention, 16(4): 737—749. (in Chinese) 袁晓铭, 秦志光, 刘荟达等, 2018. 砾性土层液化的触发条件. 岩土工程学报, 40(5): 777—785Yuan X. M. , Qin Z. G. , Liu H. D. , et al. , 2018. Necessary trigger conditions of liquefaction for gravelly soil layers. Chinese Journal of Geotechnical Engineering, 40(5): 777—785. (in Chinese) 中华人民共和国建设部, 中华人民共和国国家质量监督检验检疫总局, 2009. GB 50021—2001 岩土工程勘察规范(2009年版). 北京: 中国建筑工业出版社.Ministry of Construction of the People's Republic of China, General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China, 2009. GB 50021—2001 Code for investigation of geotechnical engineering. Beijing: China Architecture & Building Press. (in Chinese) 周神根, 1980. 静力触探判别砂土液化. 岩土工程学报, 2(3): 38—45Zhou S. G. , 1980. Evaluation of the liquefaction of sand by static cone penetration test. Chinese Journal of Geotechnical Engineering, 2(3): 38—45. (in Chinese) Robertson P. K. , Wride C. E. , 1998. Evaluating cyclic liquefaction potential using the cone penetration test. Canadian Geotechnical Journal, 35(3): 442—459. doi: 10.1139/t98-017 Seed H. B. , Idriss I. M. , Arango I. , 1983. Evaluation of liquefaction potential using field performance data. Journal of Geotechnical Engineering, 109(3): 458—482. doi: 10.1061/(ASCE)0733-9410(1983)109:3(458)