地震作用下含软弱层岩体边坡锚固界面剪切作用分析
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摘要
基于FLAC~(3D)软件,以含软弱层的锚固岩体边坡为研究对象,通过修正的cable单元建模和改进剪应力提取方法,分别模拟分析了地震作用下含软弱层岩体边坡两锚固界面剪切作用及其演化。研究发现:砂浆-岩体界面上的剪应力远比锚杆-砂浆界面上的小,并均以锚杆上的中性点为界方向相反,分布很不均匀,且均在中性点附近发生突变;随边坡地震响应增强危岩中的锚固界面率先脱黏,基岩中的锚固界面紧随脱黏,且脱黏分别向锚头和锚根发展,直至拉拔段或锚固段全部脱黏锚固破坏。获得了地震波作用下边坡两锚固界面上剪应力及其分布和脱黏破坏过程,揭示了锚固界面上的剪切相互作用和锚固破坏机制,并得到了试验印证,为边坡锚固设计和施工提供了参考。
In this study, the anchored rock slope with weak intercalated layers was investigated by using the FLAC~(3D) software. The modified cable element modeling and improved shear stress extraction method were used to analyze the shear between two anchorage interfaces of the anchored rock slope and its evolution law, respectively. The results showed that the shear stress at the mortar-rock interface was much smaller than that at the anchor-mortar interface, while these two shear stresses extended in opposite directions from the neutral point on the anchor rod. In addition, the shear stress distributed unevenly and mutated near the neutral point. With the increase of the seismic response of the slope, the anchorage interface in the unstable rock was first debonded, and then the anchorage interface in the bedrock was also debonded. Meanwhile, the debonding propagated toward the anchor head and the anchor root, respectively, until the pull-out section or the anchorage section was completely debonded and destroyed. We obtained the shear stress, the distribution of shear stress, and the debonding failure process at two anchorage interfaces of the slope under earthquake. The shearing interaction and anchorage failure mechanism at the anchorage interface were revealed and verified by experiments. The research results provide important references for the design and construction of the anchorage slope.
In this study, the anchored rock slope with weak intercalated layers was investigated by using the FLAC~(3D) software. The modified cable element modeling and improved shear stress extraction method were used to analyze the shear between two anchorage interfaces of the anchored rock slope and its evolution law, respectively. The results showed that the shear stress at the mortar-rock interface was much smaller than that at the anchor-mortar interface, while these two shear stresses extended in opposite directions from the neutral point on the anchor rod. In addition, the shear stress distributed unevenly and mutated near the neutral point. With the increase of the seismic response of the slope, the anchorage interface in the unstable rock was first debonded, and then the anchorage interface in the bedrock was also debonded. Meanwhile, the debonding propagated toward the anchor head and the anchor root, respectively, until the pull-out section or the anchorage section was completely debonded and destroyed. We obtained the shear stress, the distribution of shear stress, and the debonding failure process at two anchorage interfaces of the slope under earthquake. The shearing interaction and anchorage failure mechanism at the anchorage interface were revealed and verified by experiments. The research results provide important references for the design and construction of the anchorage slope.
引文
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[12]张玉芳,袁坤.双锚固段新型锚索锚固性能研究及工程应用[J].岩土力学,2018,39(增刊1):461-468.ZHANG Yu-fang,YUAN Kun.Experimental study and application of anchor performance of a new type anchor cable with double anchor[J].Rock and Soil Mechanics,2018,39(Suppl.1):461-468.
[13]韩军,陈强,刘元坤,等.锚杆灌浆体与岩(土)体间的黏结强度[J].岩石力学与工程学报,2005,24(19):84-88.HAN Jun,CHEN Qiang,LIU Yuan-kun,et al.Bond strength between anchor grout and rock or soil masses[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(19):84-88.
[14]重庆市城乡建设员会.GB50330-2013.建筑边坡工程技术规范[S].北京:中国建筑工业出版社,2013.Chongqing Urban and Rural Construction Commission.GB50330-2013.Technical code for building slope engineering[S].Beijing:China Architecture and Building Press,2013.
[15]谈一评,曾镇强.简谐动力波作用下锚杆拉拔试验研究[J].岩土工程学报,2013,35(3):409-414.TAN Yi-ping,ZENG Zhen-qiang.Pull-out tests on anchor bolts under simple harmonic waves[J].Chinese Journal of Geotechnical Engineering,2013,35(3):409-414.
[16]WU S X.Dynamic experimental study of bond-slip between bars and the concrete in Xiaowan arch dam[C]//New Developments in Dam Engineering Wieland.London:Taylor and Francis Group,2004:951-959.
[2]程良奎,范景伦,韩军,等.岩土锚固[M].北京:中国建筑工业出版社,2003:8-11.CHENG Liang-kui,FAN Jing-lun,HAN Jun,et al.Anchoring in soil and rock[M].Beijing:China Architecture and Building Press,2003.
[3]任非凡,徐超,谌文武.多界面复合锚杆荷载传递机制的数值模拟[J].同济大学学报(自然科学版),2011,39(12):1753-1759.REN Fei-fan,XU Chao,CHEN Wen-wu.Numerical simulation on load transfer mechanism of multi-interface composite rockbolt[J].Journal of Tongji University(Natural Science),2011,39(12):1753-1759.
[4]张桂花.全长锚固锚杆的剪应力分布规律研究[J].煤炭工程,2012,10:92-95.ZHANG Gui-hua.Study on shear stress distribution law of full length anchor bolt[J].Journal of Coal Engineering,2012,10:92-95.
[5]雒亿平,史盛,言志信.抗拔荷载作用下锚固体与岩土体界面剪切作用[J].煤炭学报,2015,40(1):58-64.LUO Yi-ping,SHI Sheng,YAN Zhi-xin.Shear interaction of anchorage body and rock and soil interface under the action of uplift load[J].Journal of China Coal Society,2015,40(1):58-64.
[6]李怀珍,李学华.基于界面滑移脱黏的锚杆合理锚固长度研究[J].岩土力学,2017,38(11):3106-3112+3172.LI Huai-zhen,LI Xue-hua.Determination of rational anchorage length of bolt based on slip-debonding failure mode of interface[J].Rock and Soil Mechanics,2017,38(11):3106-3112+3172.
[7]叶海林,郑颖人,黄润秋,等.锚杆支护岩质边坡地震动力响应分析[J].后勤工程学院学报,2010,26(4):1-7.YE Hai-lin,ZHENG Ying-ren HUANG Run-qiu,et al.Analysis of dynamic response of rockbolt in rock slope under earthquake[J].Journal of Logistical Engineering University,2010,26(4):1-7.
[8]MORTAZAVI A,ALAVI F T.A numerical study of the behavior of fully grouted rockbolts under dynamic loading[J].Soil Dynamics and Earthquake Engineering,2013,54:66-72.
[9]言志信,张刘平,江平,等.锚固上覆红黏土岩体边坡的地震动力响应[J].岩土力学,2014,35(3):753-758.YAN Zhi-xin,ZHANG Liu-ping,JIANG Ping,et al.Dynamic response of anchoring overlying red clay rock slope under earthquake action[J].Rock and Soil Mechanics,2014,35(3):753-758.
[10]董建华,朱彦鹏.框架锚杆支护边坡地震响应分析[J].兰州理工大学学报,2008,34(2):118-124.DONG Jian-hua,ZHU Yan-peng.Seismic behavior of a slope protected by a soil nailing retaining wall during an earthquake[J].Journal of Lanzhou University of Technology,2008,34(2):118-124.
[11]叶根飞.岩土锚固荷载传递规律与锚固特性试验研究[D].西安:西安科技大学,2012.YE Gen-fei.Law of anchorage load transfer and experimental study on anchoring characteristics[D].Xi’an:Xi’an University of Science and Technology,2012.
[12]张玉芳,袁坤.双锚固段新型锚索锚固性能研究及工程应用[J].岩土力学,2018,39(增刊1):461-468.ZHANG Yu-fang,YUAN Kun.Experimental study and application of anchor performance of a new type anchor cable with double anchor[J].Rock and Soil Mechanics,2018,39(Suppl.1):461-468.
[13]韩军,陈强,刘元坤,等.锚杆灌浆体与岩(土)体间的黏结强度[J].岩石力学与工程学报,2005,24(19):84-88.HAN Jun,CHEN Qiang,LIU Yuan-kun,et al.Bond strength between anchor grout and rock or soil masses[J].Chinese Journal of Rock Mechanics and Engineering,2005,24(19):84-88.
[14]重庆市城乡建设员会.GB50330-2013.建筑边坡工程技术规范[S].北京:中国建筑工业出版社,2013.Chongqing Urban and Rural Construction Commission.GB50330-2013.Technical code for building slope engineering[S].Beijing:China Architecture and Building Press,2013.
[15]谈一评,曾镇强.简谐动力波作用下锚杆拉拔试验研究[J].岩土工程学报,2013,35(3):409-414.TAN Yi-ping,ZENG Zhen-qiang.Pull-out tests on anchor bolts under simple harmonic waves[J].Chinese Journal of Geotechnical Engineering,2013,35(3):409-414.
[16]WU S X.Dynamic experimental study of bond-slip between bars and the concrete in Xiaowan arch dam[C]//New Developments in Dam Engineering Wieland.London:Taylor and Francis Group,2004:951-959.