信心

说到“信心”,我们大多数人立刻就会联想到:瞎子看见、瘸子行走、聋子听见、死人复活、长大麻风的得洁净、大山移到海里、大敌溃不成军、风止浪静、日月停转……是的,这一切是真实信心所产生的结果。一位牧师说:“神赐下信心,不是要我们用它来行神迹,而是要我们因此讨神的喜悦——这才是一切神迹中最大的。”

Research on the sudden changes and the controlling factors of deep coal mining conditions

It was illustrated that the mining conditions inducing disasters changed with depth both in regularity of gradual and sudden change.The sudden change depth for different disaster conditions are different and controlled by different factors.The high temperature and its change with depth are mainly controlled by strata structures and rock heat conductiv- ity property,the high rock stress and dynamical engineering disasters and their change with depth are mainly controlled by tectonic conditions,roof strata rock property and deep rock mechanical property,coal mine water disasters and their change with depth are mainly con- trolled by rock mechanical property of coal seam floor and regional groundwater circulation conditions,gas disaster conditions and their change with depth are mainly controlled by buried conditions of coal seam and opening conditions of geological structures.It is men- tioned that the key point for the control of deep coal mining disaster is to clearly understand the sudden change depth of different factors causing disasters.

Formation of methane hazard in longwall coal mines with increasingly higher production capacity

Increasingly higher hard coal production capacity in Upper Silesian Coal Basin(Poland) in the last two decades led to significant increase of methane hazard occurrence in the workings of exploitation areas.An increase of methane content in the exploited seams and in the surrounding strata, associated with increasing depth of mining, results in higher methane emission into the longwall areas from exploited seams and degassing seams in the mining-induced de-stressed zone. Operational experience gained by the collieries confirms that reducing methane release during longwall operations often requires decreasing operating speed of a shearer in a shift. The paper presents an analysis of the parameters and factors,which have critical influence on the formation of methane hazard in longwall areas with high production capacity.

Mechanism of water-inrush from fault induced by mining near the working face

Adopted the fractal tree-like failure model, and established the renormalization group transform function of fractured fault, and investigated the mechanism of water-inrush from fault, and found out the critical probability of water-inrush from fault caused by fault fracture. The results indicate： when the failure rate P is less than the critical failure rate Pc=0.206 3, the failure of the system is just partial. When P is more than the critical failure rate Pc=0.206 3, the random distributed crannies concentrate to certain domain of attraction （such as the maximum shear stress face in the fault） gradually. The process will continue until the crannies run-through, forming conductivity channel, and cause water-inrush from fault.

Research on prevention and cure against heat-harm in constructing mines

With the mine exploitation depth getting deeper and deeper, the mine heat-harm turns into another natural disaster after the five disasters, which are the roof, the gas, the fire, the dust and the flood disaster. Compared with other researches on prevention and cure against the heat-harm, the research on prevention and cure against the heat-harm in constructing mine are less. Referring to the experience of prevention and cure against the heat-harm home and ＇abroad, analyzing the characteristic of cooling in the constructing mine, and based on the ground former freezing equipments and the modified mine temporary cooling equipments, the paper proposed four technical projects. By comparing with the four technical projects, the second project is preponderant both in technology and economy and can solve the heat-harm of the constructing mine, which is proved by the forecast and calculation. The project can be widely applied in de-temperature tasks of high temperature and heat-harm mines during the mine constructing period and in the exploiting preparing phase.

Developing a risk assessment system for gas tunnel disasters in China

Gas disasters always restrict the tunnel constructions in mountain area, which becomes a major geological barrier against the development of underground engineering. China is rich in coal resources and has a large amount of gas with a wide range of distribution. However, China experienced not only adverse effects on coal mining but also gas disasters in underground engineering construction, such as tunnels and chambers. With the increased number of tunnels passing through coal-bearing strata, the incidence of gas accidents is also rising. Therefore, the significance of preventing and mitigating gas disasters should be emphasized, and an effective risk assessment method for gas disasters should be established. On the basis of research on over 100 gas tunnels in China, a relatively ideal gas disaster risk assessment method and system for tunnels are established through the following measures. Firstly, geo-environmental conditions and gas situations were analyzed during construction. Secondly, qualitative analysis was combined with quantitative analysis. Finally, the influencing factors of gas disasters, including geological conditions, gas,and human factors, were investigated. The gas tunnel risk assessment system includes three levels:(1) the grading assessment of a gas tunnel during the planning stage,(2) the risk assessment of gas tunnel construction during the design and construction stages,(3) the gas tunnel outburst risk assessment during the coal uncovering stage. This system was applied to the dynamic assessment of gas disaster during the construction of the Zipingpu tunnel of Dujiangyan–Wenchuan Highway(in Sichuan, Southwest China). The assessment results were consistent with the actual excavation, which verified the rationality and feasibility of the system. The developed system was believed to be back-up and applied for risk assessment of gas disaster in the underground engineering construction.

The principle analysis of methane explosion suppressed by water column curtain in coal mining

The principles of fine water mist explosion-extinguishing system was introduced. The defects of current systems were analyzed. The concept of a new water column cur-tain and the explosion-extinguishing mechanism were given. Using water column curtain to suppress methane explosion in experiment pipes was conducted. The photos were written with schlieren photograph system. The results of experiment show that the effect is perfect.

DISASTER ANALYSIS AND COUNTERMEASURES OF LAND SUBSIDENCE CAUSED BY COAL CUTTING IN CHINA

In recent years, many coal-producing countries have paid great atte ntion to the land subsidence caused by coal cutting. In China, because of the de nse population in coalfield areas, the land subsidence hazard is more serious. A fter a brief analysis on the mechanism of land subsidence, this paper gives a co mprehensive and systematical account on all kinds of hazards caused by the land subsidence in China. The study shows that land subsidence has endangered land, b uildings, traffic and communication lines, dykes and dams. It also causes damage to ecological and social environment. In order to lessen the hazard of land sub sidence, preventive measures should be taken to reduce the collapse amount, such as extraction with stowing, banded mining system, succession and coordination m ining system, or high-pressure mudflow between rock strata. Measures of reinfor cing or moving certain buildings should also be taken to reduce the destructive degree. In order to harness the subsidence land and bring them under control for farming, measures should be taken such as filling with spoil or fine breeze, ex cavating the deeper and covering the shallower land.

Research on inversion high mining pressure distribution and technology of preventing dynamic disasters by MS monitoring in longwall face

Under two rock strata combination conditions, over 10,000 microseismic events were received with microseismic location monitoring technology which possessed by the author＇s studying team, used in fully mechanized coal face of Huafeng Mine of Xinwen Coal Mining Group Co., Shandong Province. On the basis of the achievement of the location results, the conclusions were drawn as follows： On the basis of the achievement of 3D strata fracturing situation and the section plane of microseimic events in different areas, the relationship between spatial structure of overlying strata and mining pressure field was found, and we might describe distribution range of dynamic pressure of advance pressure and lateral stress around long face, and range of structure ad-tivation. Quantitative guidance to prevent dynamic disasters was provided. The practice in coal mine got a effective results. According to the FLAG3D soft numerical simulation of diameter drilling hole （the diameter is 300 mm） to relieve pressure in specified geological condition in Huafeng Mine, the right distance of two dirlls is 2.5 m and the right depth is 12 m. The research pro-vided basic guiding and practical experiences for the underground microseismic monitoring and disaster prevention in side slopes or tunnels engineering.

Sedimentation effects of the Dongting Lake Area

According to a long series of measured sediment data, the sedimentation effects of the Dongting Lake Area （DIP,） were studied in light of the relationship between sedimentation characteristics and resources and environment. The result shows that the long-term deposition and the impact of human activities have led to a cycle of the evolution of sedimentation pattern, resulting in sediment disaster effects and resources effects in the DLA. The main features are as follows： 1） The water beach, silt beach, lake marsh beach, reed beach and other types of beach shaped by sedimentation effects constitute the main body of the giant lake system. 2） The disaster chains are induced, i.e., sedimentation → marshland expansion and reclamation → flood function decline, fish resource depletion, biodiversity reduction dis- aster chain, sedimentation → marshland expansion → floods, water pollution disaster chain, sedimentation → marshland floating vegetation rising → schistosomiasis, rodents virulence disaster chain, sedimentation → flood embankment bursting → land desertification disaster chain. 3） Sedimentation has created about 98.13×10^4 hm^2 of land in the past 55 years. Rational development and utilization of marshland resources have produced tremendous economic benefits.

A public Cloud-based China's Landslide Inventory Database(Cs LID): development, zone, and spatiotemporal analysis for significant historical events, 1949-2011

Landslide inventory plays an important role in recording landslide events and showing their temporal-spatial distribution. This paper describes the development, visualization, and analysis of a China's Landslide Inventory Database(Cs LID) by utilizing Google's public cloud computing platform. Firstly, Cs LID(Landslide Inventory Database) compiles a total of 1221 historical landslide events spanning the years 1949-2011 from relevant data sources. Secondly, the Cs LID is further broken down into six zones for characterizing landslide cause-effect, spatiotemporal distribution, fatalities, and socioeconomic impacts based on the geological environment and terrain. The results show that among all the six zones, zone V, located in Qinba and Southwest Mountainous Area is the most active landslide hotspot with the highest landslide hazard in China. Additionally, the Google public cloud computing platform enables the Cs LID to be easily accessible, visually interactive, and with the capability of allowing new data input to dynamically augment the database. This work developed a cyber-landslide inventory and used it to analyze the landslide temporal-spatial distribution in China.

Post-fire Behavior of Ordinary Concrete Reinforced with Short Steel Fibers

Concrete is a widely used material in civil construction and may be submitted to high working temperatures under various circumstances. Many factors influence the behavior of this material at high temperatures, which usually leads to the evaporation of the hydrated cement. The dehydrated cement undergoes a contraction, simultaneously with the thermal expansion of the inert fraction of the material. As a consequence of these conflicting expansions and contractions, the material cracks and its strength and modulus of elasticity decrease significantly. On the other hand, the addition of short metallic fibers to the material increases its toughness, probably due to its action on the cracking behavior of the composite. It is thus expected that a concrete containing metallic fibers should maintain its original properties even after exposure to elevated temperatures. This paper presents an evaluation of the influence of steel fibers on the microstructure and toughness of concretes submitted to high tenaperatures. The bending behavior, under strain rate control, of concretes with a strength of 30 MPa and containing short steel fibers, submitted to a previous treatment at 500 ℃, was analyzed. It was observed that, after both heat treatments, the addition of metallic fibers to concrete was able to maintain the pseudo-ductility and load-carrying capacity of this composite material.

Moment-Rotation Characteristics for Flexible Beam-to-Column Steel Joint Exposed to Fire

Analytical models used to describe behaviour of steel frame loadbearing structures in fully developed fire usually do not allow for reduced joint stiffness due to increased member temperature. Joints previously designed as nominally rigid tend to become flexible in fire situation, with degree of flexibility increasing during fire development. Reliable analysis of this phenomenon and its influence on the redistribution of internal forces result in the need for developing appropriate characteristics, describing relationship between bending moment applied to the joint and joint rotation. Characteristics of such type, specified for fire conditions, depend on steel temperature, in the current work, the authors propose a practical approach to develop such characteristics, based on the knowledge of analogous characteristic prepared for persistent design situation. The developed technique does not require to generalize the classical component method to the case of fire, which may be difficult in practical situations. The proposed computational algorithm has been tested on an example of a typical beam-to-column joint.

灾年巧种田 增收百万元

于洪区是沈阳市的老水田区,渠网纵横、池埂交错。这个区的领导算了一笔帐:全区水田23万亩,按2.5％造埂率计算,池埂占地达8200亩,如果将这部分池埂地利用60％,就等于再造耕地5000多亩。这笔帐一算使全区的干部都受到震动。去年全区动员。

Induced earthquakes in the development of unconventional energy resources

It has long been known that human activities such as waste fluid disposal and reservoir impoundment may cause earthquakes. Recently, anthropogenic activities to tackle the increasing energy demand and to address climate change issues are also reported to induce earthquakes. These activities have a common attribute in that fluids are injected and extracted underground and induce spatiotemporal changes of pore pressure and stress, which may cause slip on faults. Induced earthquakes not only pose significant impacts on seismic hazard assessment and preparation, but also raise the question to the society as how to balance the economic needs of resources development and the public's concerns about potential environmental impacts. Here we review the observations of fluid-injection/extraction induced earthquakes, ground deformation associated with these activities, and their physical mechanisms. Furthermore, we discuss the influences of induced earthquakes on seismic hazard models, regulatory policies on these anthropogenic activities, and current development of academic, industrial and government initiatives and collaborations in order to understand this intriguing phenomenon and address associated challenges.

Hydropower Projects on Se San River Impact on Social Economical Development and Environmental Protection

Se San river is one of main branches of Me Kong river, it has rather rich water resource, and the topographical condition of the catchment and river are very good for hydropower development. The aquatic life in Se San River is rich, both with respect to species diversity and biomass. There are about 120 fish species are recorded, but the number of species is most likely higher, in the range from 200-300 species, fish is a very important food source for the local people. Up to now, in the Vietnam part of the Se San catchment there are 6 hydropower projects along Se San river from upstream to Vietnam – Cambodia boundary, and Se San 4A re-regulation reservoir. In the part catchment in Cambodia, in development plan there will be 3 hydropower projects, they are Se San 5/lower Se San 1, lower Se San 3, and lower Se San 2. The hydropower projects on Se San river have impacts on socio-economical development of the region （Vietnam and Cambodia） such as create new energy sources and product condition for remote and difficult areas of the catchmnet, improve the transportation system and living conditions for the rural areas. These hydropower projects also have impacts on natural environment such as flow regime changes at downstream, sediment in downstream river reaches, and some impacts on the ecosystems along river.

Towards a Local-Level Resilience Composite Index: Introducing Different Degrees of Indicator Quantification

Within disaster resilience research there is a trend of developing quantitative metrics for resilience analysis. Quantitative indicators can be useful for decision makers in the field of resilience building to prioritize preventive actions to target the least resilient. This study explores possibilities and constraints in quantifying disaster resilience at the local level. While national or regionallevel indicators mostly employ existing secondary source data, at the local level it is necessary to collect new data in most cases. The main aim of this study is to investigate how resilience indicators with different stages of operationalization can be developed at the local level. Using the example of the Swiss canton of Grisons, three local-level partial indicators for community resilience against natural hazard are developed. In this process qualitative research is the necessary basis to construct quantitative indicators. For each partial indicator different stages of quantification are offered to illustrate how quantitatively operationalized indicators can be developed and to examine their strengths and weaknesses. For this purpose a classification of different indicator operationalization stages is proposed,ranging from vague qualitative criteria to fully quantified criteria.