In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rock...In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rocks engineering in Liuhai mine,according to the methods of geological survey,theoretical analysis,numerical calculation and in-situ test,the composite failure mechanism of molecular expansion,tectonic stress,gravity stress and engineering deviatoric stress,faults and random joint in this area is analyzed deeply,then an coupling support of double-layer-truss is proposed.The research results show that the first wave of deformation energy was released by bolt-mesh-cable fixed into the roof,floor and two sides of the roadway.While the second wave of deformation energy was released through the interface function between double-layer-truss and the surrounding rock.The double-layer-truss that characterized by high strength,good integrity can absorb high deformation energy of surrounding rocks,which led to the uniform distribution of the stress.Engineering practice shows this technology has been successfully applied to control the deformation failure of the tertiary extremely soft rock roadway.展开更多
In the Alborz Mountains of the eastern Roodbar (north of Iran), Tertiary volcanic rocks have a variety of composition between olivine basalt, basaltic andesite, pyroxene andesite and andesite. The presence of differen...In the Alborz Mountains of the eastern Roodbar (north of Iran), Tertiary volcanic rocks have a variety of composition between olivine basalt, basaltic andesite, pyroxene andesite and andesite. The presence of different xenoliths and xenocrysts is among the evidence of crustal contamination of these rocks. The positive correlations of CaO/Al<sub>2</sub>O<sub>3</sub> vs to MgO and Al<sub>2</sub>O<sub>3</sub> vs. SiO<sub>2</sub> are of signs of the olivine and clinopyroxene fractionation in the variation trend of the area rocks. Positive correlations K<sub>2</sub>O/P<sub>2</sub>O<sub>5</sub> vs with SiO<sub>2</sub> and La/Sm vs. K<sub>2</sub>O/P<sub>2</sub>O<sub>5</sub> demonstrate contamination of magma with the continental crust. The incompatible trace element patterns and their comparison with crustal contents indicate contamination of the rocks of the area with the lower and upper continental crust. Linear trends in the variation diagram of Nb/Y vs. Zr/Y, introduce two different source regions: a MORB source and the other continental crust for the rocks which are the genesis. The variations of Y/Nb vs. Zr/Nb and Rb/Y vs. Nb/Y reveal a crustal contamination of the magma originated from the MORB source. Geochemical studies represent that the area’s rocks were derived from the 15% melting of a mantle source of MORB type with spinel facies within a continental environment, which was contaminated by varying degrees of continental crustal rocks.展开更多
He and Ar isotopes of the Tertiary volcanic rocks from Jiyang basin and nearby Shanwang and Qixia areas in Shandong peninsula have been analyzed. The results show that all samples are characterized by an enrichment of...He and Ar isotopes of the Tertiary volcanic rocks from Jiyang basin and nearby Shanwang and Qixia areas in Shandong peninsula have been analyzed. The results show that all samples are characterized by an enrichment of radiogenic 4He leading to extremely low 3He/ 4He ratios (0.017 8- 3.225)×10 -6 . They also have atmospheric like 38 Ar/ 36 Ar ratios and slightly higher 40 Ar/ 36 Ar ratios (395.4-1 312.7) than air value. The enrichment of radioactive 4He is attributed to the long term radiogenic accumulation of U and Th in the mantle. The low concentration of 3He is considered to be due to 3He loss during magma eruption. The loss is more obvious in the Neogene than in the Paleogene. Low 40 Ar/ 36 Ar ratios of all volcanic rocks may imply that subducted materials with atmospheric components have been preserved in the mantle, thus indicating that crust mantle circulation occurred.展开更多
According to tectonic position and mineral inclusions, supply resource in western Qaidamu basin is di- vided into the front of Aerjinshan mountain and the front of Qimantageshan mountain. The former is mainly composed...According to tectonic position and mineral inclusions, supply resource in western Qaidamu basin is di- vided into the front of Aerjinshan mountain and the front of Qimantageshan mountain. The former is mainly composed of zircon, garnet inclusions, indicating that its mother rocks are mainly metamorphic rocks. Gas and zircon, iron ore, carbon grain inclusions is common in the front of Qimantage mountain, indicating that its mother rock are mainly magmatite and mixed metamorphic rocks. The supply resource is abundant and tectonic movement is active in the joint of the two mountains. The western Qaidamu basin is further divided into 6 heavy mineral sub-regions according to their features of association and stable coefficient of heavy mineral. They are approximately corresponding to their sedimentary environment. Of the 6 sub-regions, the unstable region is corresponding to fluvial fan, middle stable re- gion is corresponding to river-alluvial plain-delta, stable region is corresponding to river-alluvial plain -delta-offshore. The fragment transported distance is presumed based on stable coefficient. In vertical, stable coefficient of heavy min- eral becomes small from Xiaganchai formation to Xiayoushashan formation, indicating that the supply resource be- came nearer and nearer.展开更多
为探究隧道穿越第三系半成岩富水段时引发的涌水突泥、冒顶等地质灾害机制,依托云南临清高速公路王家寨隧道,通过室内力学试验和模糊层次分析法,对第三系半成岩力学特性、作用机制及涌水突泥灾害风险进行分析。研究表明:1)王家寨隧道第...为探究隧道穿越第三系半成岩富水段时引发的涌水突泥、冒顶等地质灾害机制,依托云南临清高速公路王家寨隧道,通过室内力学试验和模糊层次分析法,对第三系半成岩力学特性、作用机制及涌水突泥灾害风险进行分析。研究表明:1)王家寨隧道第三系半成岩遇水软化特性明显,随着含水率增加其黏聚力先增后减,内摩擦角不断减小,含水率为18%时黏聚力与内摩擦角分别为12.53 k Pa和7.35°,围岩逐渐失稳。2)软弱的第三系半成岩、高地下水量及隧道开挖扰动为王家寨隧道第三系半成岩富水段发生涌水突泥灾害的主要影响因素。3)王家寨隧道第三系半成岩段可按工程地质条件、水文地质条件划分为A、B、C、D 4段,各段涌水突泥灾害风险由大到小排序为B段=C段>A段>D段,其中评估的A段涌泥量与实际涌泥量较为吻合。展开更多
基金supported by program for the National Natural Science Foundation of China (No.51304210)the Specialized Research Foundation for the Doctoral Program of Higher Education by the Ministry of Education (No.20120023120014)
文摘In view of failure phenomena with nonlinear large deformation including extensive damage,whole section destruction in short time,high rate of repair,most destruction forms occurred in the tertiary roadway of soft rocks engineering in Liuhai mine,according to the methods of geological survey,theoretical analysis,numerical calculation and in-situ test,the composite failure mechanism of molecular expansion,tectonic stress,gravity stress and engineering deviatoric stress,faults and random joint in this area is analyzed deeply,then an coupling support of double-layer-truss is proposed.The research results show that the first wave of deformation energy was released by bolt-mesh-cable fixed into the roof,floor and two sides of the roadway.While the second wave of deformation energy was released through the interface function between double-layer-truss and the surrounding rock.The double-layer-truss that characterized by high strength,good integrity can absorb high deformation energy of surrounding rocks,which led to the uniform distribution of the stress.Engineering practice shows this technology has been successfully applied to control the deformation failure of the tertiary extremely soft rock roadway.
文摘In the Alborz Mountains of the eastern Roodbar (north of Iran), Tertiary volcanic rocks have a variety of composition between olivine basalt, basaltic andesite, pyroxene andesite and andesite. The presence of different xenoliths and xenocrysts is among the evidence of crustal contamination of these rocks. The positive correlations of CaO/Al<sub>2</sub>O<sub>3</sub> vs to MgO and Al<sub>2</sub>O<sub>3</sub> vs. SiO<sub>2</sub> are of signs of the olivine and clinopyroxene fractionation in the variation trend of the area rocks. Positive correlations K<sub>2</sub>O/P<sub>2</sub>O<sub>5</sub> vs with SiO<sub>2</sub> and La/Sm vs. K<sub>2</sub>O/P<sub>2</sub>O<sub>5</sub> demonstrate contamination of magma with the continental crust. The incompatible trace element patterns and their comparison with crustal contents indicate contamination of the rocks of the area with the lower and upper continental crust. Linear trends in the variation diagram of Nb/Y vs. Zr/Y, introduce two different source regions: a MORB source and the other continental crust for the rocks which are the genesis. The variations of Y/Nb vs. Zr/Nb and Rb/Y vs. Nb/Y reveal a crustal contamination of the magma originated from the MORB source. Geochemical studies represent that the area’s rocks were derived from the 15% melting of a mantle source of MORB type with spinel facies within a continental environment, which was contaminated by varying degrees of continental crustal rocks.
文摘He and Ar isotopes of the Tertiary volcanic rocks from Jiyang basin and nearby Shanwang and Qixia areas in Shandong peninsula have been analyzed. The results show that all samples are characterized by an enrichment of radiogenic 4He leading to extremely low 3He/ 4He ratios (0.017 8- 3.225)×10 -6 . They also have atmospheric like 38 Ar/ 36 Ar ratios and slightly higher 40 Ar/ 36 Ar ratios (395.4-1 312.7) than air value. The enrichment of radioactive 4He is attributed to the long term radiogenic accumulation of U and Th in the mantle. The low concentration of 3He is considered to be due to 3He loss during magma eruption. The loss is more obvious in the Neogene than in the Paleogene. Low 40 Ar/ 36 Ar ratios of all volcanic rocks may imply that subducted materials with atmospheric components have been preserved in the mantle, thus indicating that crust mantle circulation occurred.
基金System in research area Project/OF4534 supported by CUMT Science Foundation
文摘According to tectonic position and mineral inclusions, supply resource in western Qaidamu basin is di- vided into the front of Aerjinshan mountain and the front of Qimantageshan mountain. The former is mainly composed of zircon, garnet inclusions, indicating that its mother rocks are mainly metamorphic rocks. Gas and zircon, iron ore, carbon grain inclusions is common in the front of Qimantage mountain, indicating that its mother rock are mainly magmatite and mixed metamorphic rocks. The supply resource is abundant and tectonic movement is active in the joint of the two mountains. The western Qaidamu basin is further divided into 6 heavy mineral sub-regions according to their features of association and stable coefficient of heavy mineral. They are approximately corresponding to their sedimentary environment. Of the 6 sub-regions, the unstable region is corresponding to fluvial fan, middle stable re- gion is corresponding to river-alluvial plain-delta, stable region is corresponding to river-alluvial plain -delta-offshore. The fragment transported distance is presumed based on stable coefficient. In vertical, stable coefficient of heavy min- eral becomes small from Xiaganchai formation to Xiayoushashan formation, indicating that the supply resource be- came nearer and nearer.
文摘为探究隧道穿越第三系半成岩富水段时引发的涌水突泥、冒顶等地质灾害机制,依托云南临清高速公路王家寨隧道,通过室内力学试验和模糊层次分析法,对第三系半成岩力学特性、作用机制及涌水突泥灾害风险进行分析。研究表明:1)王家寨隧道第三系半成岩遇水软化特性明显,随着含水率增加其黏聚力先增后减,内摩擦角不断减小,含水率为18%时黏聚力与内摩擦角分别为12.53 k Pa和7.35°,围岩逐渐失稳。2)软弱的第三系半成岩、高地下水量及隧道开挖扰动为王家寨隧道第三系半成岩富水段发生涌水突泥灾害的主要影响因素。3)王家寨隧道第三系半成岩段可按工程地质条件、水文地质条件划分为A、B、C、D 4段,各段涌水突泥灾害风险由大到小排序为B段=C段>A段>D段,其中评估的A段涌泥量与实际涌泥量较为吻合。
