GREY CLASSIFICATION FOR EVALUATING THE STABILITY OF DANGEROUS ROCK-BLOCK MASSES

This paper introduces a grey classifica- tion method forevaluating the stability of dangerous rock- block masses according tothe Grey System Theory. This method is applied to the stability ofthe V~# dangerous rock- block masses of Qingjiang water conservancyproject, and better results are abtained. The method which isadvanced in the article is very single and practical, and it can meetall kinds of project's demands.

Study on engineering geological stability of rock mass at Shanmen silver deposit

The natural balance conditions will be disturbed and produce a series of problems when mineral deposit has mined.This paper has researched the engineering rock masses have been researched in this study,structural planes,the distribution characteristics of tectonic geological factors and the stability of engineering structures according to the theory and research methods of rock mechanics,it will provide the engineering geological evidence for mining area exploited,meanwhile pledge the safety production.Shanmen silver deposit is a large epithermal deposit,it is controlled by NE to NNE strike faults.The stability of rock mass is acted on the tectonic movement and hot metalliferous brine in long-term.Especially,strength of rock mass becomes softened,muddy and loosed under the action of water,so the lower stability of rock mass is,the easier it can take place for harm of disaster threatening production safe of mining.For this reason,it is very important that drawing up a plan to lower harm for mine and protect.

Confining Potential and Mass of Elementary Particles

In this paper we consider a model in which the masses of elementary particles are formed and stabilized thanks to confining potential, which is caused by recoil momentum at emission of specific virtual bosons by particle itself. The calculation of this confining potential Ф(R) is carried out. It is shown that Ф(R) may be in the form const or const depending on continuous or discrete nature of the spectrum of emitted bosons.

Developments and prospects of microseismic monitoring technology in underground metal mines in China

Microseismic monitoring technology has become an important technique to assess stability of rock mass in metal mines.Due to the special characteristics of underground metal mines in China,including the high tectonic stress,irregular shape and existence of ore body,and complex mining methods,the application of microseismic technology is more diverse in China compared to other countries,and is more challenging than in other underground structures such as tunnels,hydropower stations and coal mines.Apart from assessing rock mass stability and ground pressure hazards induced by mining process,blasting,water inrush and large scale goaf,microseismic technology is also used to monitor illegal mining,and track personnel location during rescue work.Moreover,microseismic data have been used to optimize mining parameters in some metal mines.The technology is increasingly used to investigate cracking mechanism in the design of rock mass supports.In this paper,the application,research development and related achievements of microseismic technology in underground metal mines in China are summarized.By considering underground mines from the perspective of informatization,automation and intelligentization,future studies should focus on intelligent microseismic data processing method,e.g.,signal identification of microseismic and precise location algorithm,and on the research and development of microseismic equipment.In addition,integrated monitoring and collaborative analysis for rock mass response caused by mining disturbance will have good prospects for future development.

Engineering rock mechanics practices in the underground powerhouse at JinpingⅠhydropower station

Based on the analyses of data obtained from the underground powerhouse at Jinping I hydropower station, a comprehensive review of engineering rock mechanics practice in the underground powerhouse is first conducted. The distribution of strata, lithology, and initial geo-stress, the excavation process and corresponding rock mass support measures, the deformation and failure characteristics of the surrounding rock mass, the stress characteristics of anchorage structures in the cavern complex, and numerical simulations of surrounding rock mass stability and anchor support performance are presented. The results indicate that the underground powerhouse of Jinping I hydropower station is characterized by high to extremely high geo-stresses during rock excavation. Excessive surrounding rock mass deformation and high stress of anchorage structures, surrounding rock mass unloading damage, and local cracking failure of surrounding rock masses, etc., are mainly caused by rock mass excavation. Deformations of surrounding rock masses and stresses in anchorage structures here are larger than those found elsewhere： 20% of extensometers in the main powerhouse record more than 50 mm with the maximum at around 250 mm observed in the downstream sidewall of the transformer hall. There are about 25% of the anchor bolts having recorded stresses of more than 200 MPa. Jinping I hydropower plant is the first to have an underground powerhouse construction conducted in host rocks under extremely high geo-stress conditions, with the ratio of rock mass strength to geo-stress of less than 2.0. The results can provide a reference to underground powerhouse construction in similar geological conditions.

Preliminary studies on the stability of arsenolipids:Implications for sample handling and analysis

Human health risk assessments concerning arsenic are now estimating exposure through food in addition to exposure through drinking water. Intrinsic to this assessment is sample handling and preparation that maintains the arsenic species in the form that they occur in foods. We investigated the stability of three arsenolipids（two arsenic fatty acids, As FA-362 and As FA-388, and one arsenic hydrocarbon As HC-332）, common constituents of fish and algae, relevant to sample storage and transport, and to their preparation for quantitative measurements. The fate of the arsenolipids was followed by high performance liquid chromatography/electrospray triple quadruple mass spectrometry（HPLC/ESIMS） analyses.Storage of the compounds dry as pure compounds or mixed in fish oil at up to 60？C did not result in significant changes to the compounds, although losses were observed by apparent adsorption onto the plastic walls of the polypropylene tubes. No losses occurred when the experiment was repeated with glass tubes. When the compounds were stored in ethanol for up to 15 days under acidic, neutral, or alkaline conditions（each at room temperature）, no significant decomposition was observed, although esterification of the fatty acids occurred at low p H. The compounds were also stable during a sample preparation step involving passage through a small silica column. The results indicate that these typical arsenolipids are stable when stored in glass at temperatures up to 60？C for at least 2 days, and that,consequently, samples of food or extracts thereof can be transported dry at ambient temperatures, i.e. without the need for cool conditions.

Assessment of thermal stratification, stability and characteristics of deep water zone of the southern Caspian Sea

Variations of seawater properties and stratification of water column in the southern deep water zone(470 m depth)of the Caspian Sea were evaluated based on field measured data.Variations of physical characteristics(temperature,salinity,density and sound speed)of seawater mainly were limited to the upper 100 m layers.Below this layer,seasonal changes of seawater parameters were minor.Vertical structure of temperature in the southern Caspian Sea waters was characterized by a significant seasonal thermocline approximately between 20 and 50 m depths in summer with a vertical gradient of around 16℃.Destruction of the thermocline occurred with the general cooling of the sea surface water and deepening of the mixed layer during late of autumn and winter.Frequency of stability in water column often across the upper layers(surface mixed and thermocline)was more than deeper levels.Variations of salinity were around 12.4 PSU in the time of measurements.Structures of thermocline and pycnocline were characterized by a significant homogeneity especially in offshore stations during the year.According to high agreement between density and temperature in the Caspian Seawater,a strong seasonal pycnocline was observed in the position of the thermocline.Furthermore,structure of sound speed variations followed vertical variations of seawater temperature.Variations of chemical characteristics(dissolved oxygen and pH)of seawater mainly were continued from sea surface to near the sea bed in deep water zone.