摘要
生物成因的珊瑚礁灰岩明显有别于传统意义的地质岩体,通过对礁灰岩进行霍普金森压杆(SHPB)冲击试验,研究南海珊瑚礁灰岩的动力破碎形态和动态力学性能。研究表明:垂向沉积演化发育的强度高且致密的礁灰岩,具有较高的弹性波速和单轴抗压强度;单轴冲击荷载下礁灰岩主要发生沿轴向的张拉破坏,且主要发生在生物组分、珊瑚砾块与珊瑚藻的胶结面等薄弱部位;生物成因的礁灰岩的动态应力-应变模型与一般岩石不同,存在较明显的压密阶段,礁灰岩的动态抗压强度对应变率表现出更强的敏感性;礁灰岩的能耗密度、入射能和动态抗压强度呈线性关系,与应变率呈乘幂函数关系。珊瑚礁灰岩的动态力学性能对岛礁工程实践中的爆破开挖、冲击破碎和防震抗爆设计有重要的指导意义。
Biogenic coral-reef limestone is distinct from the traditional geological rock. In this study, Hopkinson pressure bar tests on coral-reef limestone are conducted to investigate the dynamic fracture morphology and dynamic properties of coral-reef limestones of the South China Sea. Research results show that the high-strength and dense coral-reef limestone with vertical sedimentary evolution has high elastic wave velocity and uniaxial compressive strength; the tensile failure of coral-reef limestone mainly occurs along axis under uniaxial impact loading, and mainly in the weak parts such as the cementation surfaces between the bio-component, coral gravel and coral algae; the dynamic stress-strain model of reef limestone has obvious compaction stage, which is different from normal rock; the dynamic compressive strength of coral-reef limestone is more sensitive to the strain rate than that of normal rock;the energy density of the coral-reef limestone is linearly related to the incident energy and the dynamic compressive strength, and it shows a power function relationship with the strain rate. The dynamic mechanical properties of coral-reef limestone has an important guiding significance for the reef engineering practices such as blasting excavation, impact crushing, earthquake proof and antiknock design.
引文
[1]王新志,汪稔,孟庆山,等.南沙群岛珊瑚礁礁灰岩力学特性研究[J].岩石力学与工程学报,2008,27(11):2221-2226.WANG Xin-zhi,WANG Ren,MENG Qing-shan,et al.Research on characteristics of coral reef calcareous rock in Nansha Islands[J].Chinese Journal of Rock Mechanics and Engineering,2008,27(11):2221-2226.
[2]唐国艺,郑建国.东南亚礁灰岩的工程特性[J].工程勘察,2015(6):6-10.TANG Guo-yi,ZHENG Jian-guo.Engineering properties of reef calcareous rock in Southeast Asia[J].Geotechnical Investigation&Surveying,2015(6):6-10.
[3]刘志伟,李灿,胡昕.珊瑚礁礁灰岩工程特性测试研究[J].工程勘察,2012(9):17-21.LIU Zhi-wei,LI Can,HU Xi.Experimental study on engineering properties of coral reef calcareous rock[J].Geotechnical Investigation&Surveying,2012(9):17-21.
[4]杨永康,丁学武,冯春燕,等.西沙群岛珊瑚礁灰岩物理力学特性试验研究[J].广州大学学报(自然科学版),2016,15(5):78-83.YANG Yong-kang,DING Xue-wu,FENG Chun-yan,et al.Experimental research on physics mechanics characteristics of coral reefs calcareous rock in Xisha Islands[J].Journal of Guangzhou University(Natural Science Edition),2016,15(5):78-83.
[5]梁文成.苏丹珊瑚礁灰岩地区地质勘察总结[J].水运工程,2009(7):151-153.LIANG Wen-cheng.Geotechnical investigation of coral-reef limestone area in Sudan[J].Port&Waterway Engineering,2009(7):151-153.
[6]卢博,宋朝景,黄韶健.南沙群岛珊瑚礁和礁灰岩弹性波分类的初步研究[J].南海研究与开发,1996(3):12-15.LU Bo,SONG Chao-jing,HUANG Shao-jian,et al.Preliminary study on elastic wave classification of coral reef and reef limestone in Spratly Islands[J].Research&Development of South China Sea,1996(3):12-15.
[7]孙宗勋,卢博.南沙群岛珊瑚礁灰岩弹性波性质的研究[J].工程地质学报,1999,7(2):175-180.SUN Zong-xun,LU Bo.Elastlc wave properties of coral reef rock in Nansha Islands[J].Journal of Engineering Geology,1999,7(2):175-180.
[8]长江水利委员会长江科学院.SL264-2001水利水电工程岩石试验规程[S].北京:中国水利水电出版社,2001.Changjiang River Scientific Research Institute of Changjiang Water Resources Commission.SL264-2001Specification for rock tests in water conservancy and hydroelectric engineering[S].Beijing:China Waterpower Press,2001.
[9]ZHOU Y X,XIA K,LI X B,et al.Suggested methods for determining the dynamic strength parameters and mode-Ifracture toughness of rock materials[J].International Journal of Rock Mechanics and Mining Sciences,2012,49:105-112.
[10]丰平,张庆明,陈利,等.SHPB测试中斜坡加载对应力均匀性和恒应变率的影响分析[J].北京理工大学学报,2010,30(5):513-516.FENG Ping,ZHANG Qing-ming,CHEN Li,et al.Influence of incident pulse of slope on stress uniformity and constant strain rate in SHPB test[J].Transactions of Beijing Institute of Technology,2010,30(5):513-516.
[11]宋力,胡时胜.SHPB数据处理中的二波法和三波法[J].爆炸与冲击,2005,25(4):368-373.SONG Li,HU Shi-sheng.Two-wave and three-wave method in SHPB data processing[J].Explosion and Shock Waves,2005,25(4):368-373.
[12]LANKFORD J.The role of tensile microfracture in the strain rate dependence of compressive strength of fine-grained limestone-analogy with strong ceramics[J].International Journal of Rock Mechanics&Mining Sciences&Geomechanics Abstracts,1981,18(2):173-175.
[13]李夕兵,陈寿如,古德生.岩石在不同加载波下的动载强度[J].中南大学学报(自然科学版),1994,25(3):301-304.LI Xi-bing,CHEN Shou-ru,GU De-sheng.Dynamic strength of rock under impulse loads with different stress waveforms and durations[J].Journal of Central South University(Science and Technology),1994,25(3):301-304.
[14]朱晶晶,李夕兵,宫凤强,等.冲击载荷作用下砂岩的动力学特性及损伤规律[J].中南大学学报(自然科学版),2012,43(7):2701-2707.ZHU Jing-jing,LI Xi-bing,GONG Feng-qiang,et al.Experimental test and damage characteristics of sandstone under uniaxial impact compressive loads[J].Journal of Central South University(Science and Technology),2012,43(7):2701-2707.
[15]LIU S,XU J.Study on dynamic characteristics of marble under impact loading and high temperature[J].International Journal of Rock Mechanics&Mining Sciences,2013,62(5):51-58.
[16]ZHANG Z X,KOU S Q,JIANG L G,et al.Effects of loading rate on rock fracture:fracture characteristics and energy partitioning[J].International Journal of Rock Mechanics&Mining Sciences,2000,37(5):745-762.
[17]平琦,骆轩,马芹永,等.冲击载荷作用下砂岩试件破碎能耗特征[J].岩石力学与工程学报,2015,34(增刊2):4197-4203.PING Qi,LUO Xuan,MA Xian-yong,et al.Broken energy dissipation characteristics of sandstone specimens under impact loads[J].Chinese Journal of Rock Mechanics and Engineering,2015,34(Supp.2):4197-4203.
[18]洪亮.冲击荷载下岩石强度及破碎能耗特征的尺寸效应研究[D].长沙:中南大学,2008.HONG Liang.Size effect on strength and energy dissipation in fracture of rock under impact loads[D].Changsha:Central South University,2008.