岩芯卸荷扰动的声学反应与卸荷敏感岩体
|
摘要
声波测试是工程岩体质量评价的最主要手段之一。将岩体与岩块的纵波波速比的平方定义为岩体的完整性系数,不仅为国内外学者广泛认同,而且是现行规范的定义。这是源于如下认识:原位岩体的纵波波速小于其中岩块的波速;岩体越破碎,小得越多。然而,通过润扬大桥声波测试发现,用通常手段得到的大部分岩体的测井波速反而大于岩样波速。对该桥基岩40余个钻孔数百个岩样进行了多种手段的对比研究和综合分析,探讨了测试结果的可靠性及产生原因,进而提出了岩芯卸荷扰动和卸荷敏感岩体的概念和相应的工程对策。
Ultrasonic testing is one of the most frequently used measurements in geotechnical rock mass evaluation. The square of the ratio of longitudinal wave (P-wave) velocity of rock mass to that of rock block is defined as intactness index of rock mass. As we know,the P-wave velocity of in-situ rock mass is believed to be lower than that of relevant rock block. The more broken the rock mass is,the lower its P-wave velocity is than that of rock block. However,according to the result of ultrasonic testing carried out at Runyang Highway Bridge,it is surprised to find that most P-wave velocities of rock mass are higher than that of rock block. Many different measurements are applied in the comparative research,which is based on hundreds of rock cores collected from over 40 boreholes in the bed rock of the Bridge site,and the reliability and causes of the results are analyzed. The concepts of rock core unloading disturbance and unloading-sensitive rock mass are then put forward,with relevant engineering countermeasures.
Ultrasonic testing is one of the most frequently used measurements in geotechnical rock mass evaluation. The square of the ratio of longitudinal wave (P-wave) velocity of rock mass to that of rock block is defined as intactness index of rock mass. As we know,the P-wave velocity of in-situ rock mass is believed to be lower than that of relevant rock block. The more broken the rock mass is,the lower its P-wave velocity is than that of rock block. However,according to the result of ultrasonic testing carried out at Runyang Highway Bridge,it is surprised to find that most P-wave velocities of rock mass are higher than that of rock block. Many different measurements are applied in the comparative research,which is based on hundreds of rock cores collected from over 40 boreholes in the bed rock of the Bridge site,and the reliability and causes of the results are analyzed. The concepts of rock core unloading disturbance and unloading-sensitive rock mass are then put forward,with relevant engineering countermeasures.
引文
1王让甲.声波岩石分级和岩石动弹性力学参数的分析研究[M].北京:地质出版社,1997
2林韵梅等.数值分类方法及其在岩石力学中的应用[M].沈阳:东北大学出版社,1989
3林韵梅.岩体基本质量定量分级标准BQ公式的研究[J].岩土工程学报,1999,21(4):481～485
4边智华,李维树.南京长江二桥基岩的工程力学性质试验研究[J].长江科学院院报.1999,16(4):42～45
5水利电力部昆明勘测设计院.水电站大型地下洞室围岩稳定性和支护的研究和实践成果汇编(“六五”国家科技攻关项目)[R].昆明:水利电力部昆明勘测设计院,1986
6王兴泰.工程与环境物探新方法新技术[M].北京:地质出版社,1996
7BathM.地球物理学中的谱分析[M].郑治真,叶正仁,安镇文等译.北京:地质出版社,1 978
8Seu fertPK,Gel lerJT,Jo hnsonLR. EffectofP- wa vescatte rin gonvelocity an dattenuationin unco nsolidate dsan dsaturated withimmiscibleliquids[J].Geophysics,1998,63(1):161～170
9南京大学地球科学系,江苏省交通规划设计院.润扬大桥区域稳定性与岩体质量专题研究报告[R].2000
10刘彤,徐鸣洁,胡德昭等.风化花岗岩声波频谱特征[J].高校地质学报,2000,6(4):588～594
11郭令智,施央申,马瑞士.西太平洋中新生代活动大陆边缘和岛弧构造的形成与演化[J].地质学报,1983,57(1):11～21
12张庆龙.南京地区新构造特征及其与地震关系[J].南京大学学报(地球科学),1990,(4):76～84
13张绍治.江苏地区现代构造应力场[J].江苏地质,1989,(2):3～9
14朱履熹.上海及邻区新构造应力场初步探讨[J].上海地质,1990,(1):45～55
2林韵梅等.数值分类方法及其在岩石力学中的应用[M].沈阳:东北大学出版社,1989
3林韵梅.岩体基本质量定量分级标准BQ公式的研究[J].岩土工程学报,1999,21(4):481～485
4边智华,李维树.南京长江二桥基岩的工程力学性质试验研究[J].长江科学院院报.1999,16(4):42～45
5水利电力部昆明勘测设计院.水电站大型地下洞室围岩稳定性和支护的研究和实践成果汇编(“六五”国家科技攻关项目)[R].昆明:水利电力部昆明勘测设计院,1986
6王兴泰.工程与环境物探新方法新技术[M].北京:地质出版社,1996
7BathM.地球物理学中的谱分析[M].郑治真,叶正仁,安镇文等译.北京:地质出版社,1 978
8Seu fertPK,Gel lerJT,Jo hnsonLR. EffectofP- wa vescatte rin gonvelocity an dattenuationin unco nsolidate dsan dsaturated withimmiscibleliquids[J].Geophysics,1998,63(1):161～170
9南京大学地球科学系,江苏省交通规划设计院.润扬大桥区域稳定性与岩体质量专题研究报告[R].2000
10刘彤,徐鸣洁,胡德昭等.风化花岗岩声波频谱特征[J].高校地质学报,2000,6(4):588～594
11郭令智,施央申,马瑞士.西太平洋中新生代活动大陆边缘和岛弧构造的形成与演化[J].地质学报,1983,57(1):11～21
12张庆龙.南京地区新构造特征及其与地震关系[J].南京大学学报(地球科学),1990,(4):76～84
13张绍治.江苏地区现代构造应力场[J].江苏地质,1989,(2):3～9
14朱履熹.上海及邻区新构造应力场初步探讨[J].上海地质,1990,(1):45～55
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心