Effect of Freeze-Thaw Cycles on Mechanical Properties and Permeability of Red Sandstone under Triaxial Compression   总被引：1，自引：1，他引：0  

YU Jin  CHEN Xu  LI Hong  ZHOU Jia-wen  CAI Yan-yan 《山地科学学报》2015,(1):218-231

Geological disasters will happen in cold regions because of the effects of freeze-thaw cycles on rocks or soils, so studying the effects of these cycles on the mechanical characteristics and permeability properties of rocks is very important. In this study,red sandstone samples were frozen and thawed with 0,4, 8 and 12 cycles, each cycle including 12 h of freezing and 12 h of thawing. The P-wave velocities of these samples were measured, and the mechanical properties and evolution of the steady-state permeabilities were investigated in a series of uniaxial and triaxial compression tests. Experimental results show that, with the increasing of cyclic freeze-thaw times, the P-wave velocity of the red sandstone decreases. The number of freeze-thaw cycles has a significant influence on the uniaxial compressive strength, elastic modulus, cohesion, and angle of internal friction. The evolution of permeability of the rock samples after cycles of freeze-thaw in a complete stress-strain process under triaxial compression is closely related to the variation of the microstructure in the rock. There is a highly corresponding relationship between volumetric strain and permeability with axial strain in all stages of the stress-strain behaviour.  相似文献   

峡口高地应力软岩隧道施工监测及支护对策研究     

李鸿博  戴永浩  宋继宏  付克俭 《岩土力学》2011,32(Z2):496-501

针对高应力软岩公路隧道的特点,对湖北宜巴高速公路峡口隧道开展了地应力测试、隧洞收敛下沉、接触应力、结构受力等项目的监测工作。地应力测试结果表明,虽然隧洞埋深不大,但由于构造应力的存在,仍属于高地应力区。施工监测结果表明,高应力软岩隧道变形与结构受力具有明显的时空效应,与开挖方式、工作面距离以及支护时机密切相关。由于隧洞围岩软弱破碎,加之处于高应力作用下,在工作面通过后,岩体产生持续性的流变变形,导致隧洞产生挤压大变形和结构受力的持续增加,达到支护结构强度极限,最终导致围岩失稳和支护体系的失效。基于上述研究成果,提出了相应的高应力软岩大变形支护设计对策。研究成果为高应力软岩隧道变形与结构受力的时空效应性提供了监测数据支持,为峡口隧道的施工和支护设计提供了依据,对我国西部其他高应力软岩公路隧道的建设具有借鉴意义。  相似文献   

2.5-D DC Resistivity Modeling Considering Flexibility and Accuracy     

汤井田  王飞燕  肖晓  张林成 《中国地质大学学报(英文版)》2011,(1)

We highlighted the flexibility of using unstructured mesh together with the local refinement by a resistivity model with complicated topography. The effect of topography is emphasized. Based on this, we calculated a specific class of layered models and found that the accuracy is not always satisfactory by utilizing the standard approach. As an improvement, we employed the layered earth as the reference model to calculate the wavenumbers. The comparison demonstrates that the accuracy is considerably improved...  相似文献   

Anthropogenic Sulfate and Nitrate Signals in Snow from Bogda Glacier, Eastern Tianshan     

张晓宇  Ross Edwards 《中国地质大学学报(英文版)》2011,(4)

A 1.2 m snow pit was recovered on July 29th, 2009 from the Bogda Glacier, eastern Tianshan (天山). The sample site temperature of -9.6 ℃ indicates that the unique glaciochemical re-cord was well preserved and suitable for the reconstruction of air pollution levels in this previously un-explored region. Samples were analyzed for major ions (Na+, K+, Ca2+, Mg2+, NH4+, Cl-, SO42-, NO3-, HCOO-, and CH3COO-). NO3- and SO42- were characterized by significant high levels of pollution con-centration. Most air masses ...  相似文献   

Monitoring Glacial Shrinkage Using Remote Sensing and Site-Observation Method on Southern Slope of Kalik Mountain, Eastern Tian Shan, China     

王文彬  李开明  高建芳 《中国地质大学学报(英文版)》2011,(4)

Currently, one of the effective means in monitoring glacier change in regional scale is remote sensing and site-observation method. In this article, we present a study of comparing glacier area in 2005 derived from SPOT5 satellite image with area in 1972 derived from topographic maps. Moreover, Miaoergou (庙儿沟) flat-summit glacier is site observed to verify glacial change in regional scale. During the study period, glaciers located in the southern slope of Kalik (喀尔里克) Mountain re-duced their area by 12.3%. ...  相似文献   

Deposition Process of Dust Microparticles from Aerosol to Snow-Firn Pack on Glacier No. 1 in Eastern Tianshan Mountains, China     

尤晓妮  董志文 《中国地质大学学报(英文版)》2011,(4)

Samples were continuously collected from aerosol, fresh snow, and snow pits on Glacier No. 1 at Urumqi River source in eastern Tianshan (天山) Mountains. The deposition processes and the characteristics of mineral dust microparticles from aerosol to fresh snow, and then evolution to the snow pit were determined. Total dust microparticle concentration in the surface snow and aerosol showed a similar temporal variation trend, which was strongly associated with regional and local at-mospheric circulation in the ...  相似文献   

Noble Gas Diffusion Mechanism in Lunar Soil Simulant Grains:Results from ~4He~+ Implantation and Extraction Experiments     

付晓辉  邹永廖  郑永春  贺怀宇  欧阳自远 《中国地质大学学报(英文版)》2011,(5)

Experiments on ion implantation were performed in order to better characterize diffusion of noble gases in lunar soil.4He+ at 50 keV with 5×1016 ions/cm2 was implanted into lunar simulants and crystal ilmenite.Helium in the samples was released by stepwise heating experiments.Based on the data,we calculated the helium diffusion coefficient and activation energy.Lunar simulants display similar 4He release patterns in curve shape as lunar soil,but release temperatures are a little lower.This is probably a con...  相似文献   

Hybrid Sedimentation in Late Permian-Early Triassic in Western Sichuan Basin,China     

龙胜祥  吴世祥  李宏涛  白振瑞  马金钰  张华 《中国地质大学学报(英文版)》2011,(3)

Mixed carbonate-siliciclastic sedimentation is common in the Upper Permian-Lower Tri-assic in the western Sichuan(四川) basin.The extensional movement was strong in the Late Permian,resulting in differential uplifting of fault blocks.During this period,there was an extensive retrogres-sion.The Kangdian(康滇) ancient land progressive uplifted and enlarged,forming the major prove-nance of terrigenous clastics.In Changxingian age,mixed terrigenous-carbonate sedimentation was dis-tributed in the area between Dafeis...  相似文献   

Distribution of Arsenic in Sewage Irrigation Area of Pearl River Delta,China     

黄冠星  孙继朝  张英  荆继红  张玉玺  刘景涛 《中国地质大学学报(英文版)》2011,(3)

The aim of the present work is to investigate the distribution of arsenic(As) in sewage ir-rigation area,to deduce the migration and transformation mechanism of As in soil and groundwater,and to infer the source of As in soil and groundwater.This study is carried out in a sewage irrigation area of the Pearl River Delta,China.Surface water samples,soil samples,and groundwater samples from sewage irrigation area were analyzed for As and other elements.As contents in water samples were analyzed by hydride gene...  相似文献   

Tectonics and Mechanisms of Uplift in the Central Uplift Belt of the Huimin Depression     

倪金龙  郭颖  王智敏  刘俊来  林玉祥  李月 《中国地质大学学报(英文版)》2011,(3)

The Huimin (惠民) depression is a third-level tectonic element of the Bohai (渤海) Bay basin in eastern China. The central uplift belt is the most important oil and gas accumulation zone in the depression, but the lack of adequate geological studies in the area has greatly hindered exploration and development. In this article, using seismic data, fracture mechanics, and a combination of data on fault growth indices and fault throws, we present an analysis of tectonic activity in the central uplift belt and adja...  相似文献