Analysis of debris flow control effect and hazard assessment in Xinqiao Gully,Wenchuan M_(s)8.0 earthquake area based on numerical simulation

Xinqiao Gully is located in the area of the 2008 Wenchuan M_(s)8.0 earthquake in Sichuan province,China.Based on the investigation of the 2023"6-26"Xinqiao Gully debris flow event,this study assessed the effectiveness of the debris flow control project and evaluated the debris flow hazards.Through field investigation and numerical simulation methods,the indicators of flow intensity reduction rate and storage capacity fullness were proposed to quantify the effectiveness of the engineering measures in the debris flow event.The simulation results show that the debris flow control project reduced the flow intensity by41.05%to 64.61%.The storage capacity of the dam decreases gradually from upstream to the mouth of the gully,thus effectively intercepting and controlling the debris flow.By evaluating the debris flow of different recurrence intervals,further measures are recommended for managing debris flow events.

Unraveling the hydraulic properties of loess for landslide prediction:A study on variations in loess landslides in Lanzhou,Dingxi,and Tianshui,China

Loess has distinctive characteristics,leading to frequent landslide disasters and posing serious threats to the lives and properties of local re sidents.The involvement of water repre sents a critical factor in inducing loess landslides.This study focuses on three neighboring cities sequentially situated on the Loess Plateau along the direction of aeolian deposition of loess,namely Lanzhou,Dingxi,and Tianshui,which are densely populated and prone to landslide disasters.The variations in hydraulic properties,including water retention capacity and permeability,are investigated through Soil Water Characteristic Curve(SWCC)test and hydraulic conductivity test.The experimental findings revealed that Tianshui loess exhibited the highest water retention capacity,followed by Dingxi loess,while Lanzhou loess demonstrated the lowest water retention capacity.Contrastingly,the results for the saturated permeability coefficient were found to be the opposite:Tianshui loess showed the lowest permeability,whereas Lanzhou loess displayed the highest permeability.These results are supported and analyzed by scanning electron microscopy(SEM)observation.In addition,the water retention capacity is mathematically expressed using the van Genuchten model and extended to predict unsaturated hydraulic properties of loess.The experimental results exhibit a strong accordance with one another and align with the regional distribution patterns of disasters.

Principles and technology for stepwise utilization of resources for mitigating deep mine heat hazards

As is well known, deep mines are hot. As mining depth increases, the temperature of the surrounding rock also increases. This seriously affects mine safety and production and has restricted the exploitation of deep coal resources. Therefore, reducing the working face temperature to improve working conditions by controlling these heat hazards is an urgent problem. Considering problems in cooling deep mines both domestically and abroad along with the actual conditions of the Zhangshuanglou coal mine, we propose a HEMS technology that uses heat resources from deep mines in a stepwise manner. HEMS means a high temperature ex-change machinery system. Mine inrush-water is used as a source of cooling. Twice the energy is extracted from the mine inrush water. Heat is used for building heating in the winter and cold water is used for cooling buildings in the summer. This opens a new technology for stepwise utilization of heat energy in deep mines. Energy conservation and reduced pollution, an improved environment and sustainable economic development are realized by this technique. The economic and social effects are obvious and illustrate a good prospect for the application and extension of the method.

The Occurrence and Prevention of Filamentous Algae in Ecological Purification System of Micro-polluted Water

[ Objective ] The aim was to study the influence of filamentous algae on the process of water ecological purification. [ Method ] The occurrence mechanism of filamentous algae and its ecological system were summarized and analyzed. Considering the ecological purification in north- ern Jiangsu, the occurrence and prevention of filamentous algae in water, the method to prevent filamentous algae in polluted water was discussed. [ Result] The results showed that by measures of improving planting density, regular harvesting, and water flow state control before the filamentous algae blooming period, together with improving local pH value, light interference and ecological control during the blooming period, can effectively control the filamentous algae blooming. [ Condusion] The study of the happening mechanism of filamentous algae provided theoretical references and the technical basis in the work of filamentous algae prevention and control.

Integrated Prevention and Control System for Soil Erosion in Typical Black Soil Region of Northeast China

The black soil region of Northeast China is one of the most important food production bases and commodity grain bases in China. However, the continual loss and degradation of precious black soil resources has led to direct threats to national food security and regional sustainable development. Therefore, it is necessary to summarize integrated prevention and control experience of small watersheds in black soil region of Northeast China. Tongshuang small watershed, a typical watershed in rolling hills of typical black soil areas in Northeast China, is selected as the study area. Based on nearly 50 years' experience in prevention and control of soil and water loss, the structures and overall benefits of an integrated prevention and control system for soil and water loss are investigated. Then, the 'three defense lines' tri-dimensional protection system with reasonable allocation of different types of soil and water control measures from the hill top to gully is systematically analyzed. The first line on the top hill can weaken and block uphill runoff and sediment, hold water resources and improve soil property. The second line on the hill can truncate slope length, slow down the runoff velocity and reduce erosion energy. The third line in the gully is mainly composed of waterfall engineering, which can inhibit soil erosion and restore land resources. The 'three defense lines' system is feasible for soil and water loss control of small watersheds in the typical black soil region of Northeast China. Through the application of the in Tongshuang small watershed, There are effective improvements in ecological conditions in Tongshuang small watershed after the application of 'three defense lines' soil and water control system. Moreover, the integrated treatment paradigm for soil and water loss in typical black soil region is compared with that in loess region. The results of this study could offer references and experiences for other small watersheds in typical black soil region of Northeast China.

Occurrence and Damage Characteristics of Sugarcane Catastrophic Diseases and Pests in Menglian Sugarcane Area and Their Prevention and Control Strategies

In recent years,the conditions of continuous warm winter,more rain and high humidity are very beneficial to the breeding and survival of sugarcane diseases and pests.Coupled with the degradation of single varieties,more attention on new plants and less on ratoon cane and the unscientific and unreasonable use of chemical pesticides,the types of sugarcane diseases and pests in the Menglian sugarcane area are increasing day by day,and the damage is increasing year by year,resulting in a substantial reduction in production and sugar,and a serious disaster threat to sugarcane production.Based on the field survey and the current sugarcane production practice in Menglian,this paper systematically reviewed the occurrence and damage dynamics and outbreak reasons of catastrophic diseases and pests that seriously influence sugarcane production,and proposed corresponding prevention and control strategies and integrated prevention and control technology according to the occurrence and damage characteristics of catastrophic diseases and pests.

Research progress and application prospect of functional adhesive materials in the field of oil and gas drilling and production

By summarizing the composition,classification,and performance characterization of functional adhesive materials,the adhesion mechanisms of functional adhesive materials,such as adsorption/surface reaction,diffusion,mechanical interlocking,and electrostatic adsorption,are expounded.The research status of these materials in oil and gas drilling and production engineering field such as lost circulation prevention/control,wellbore stabilization,hydraulic fracturing,and profile control and water plugging,and their application challenges and prospects in oil and gas drilling and production are introduced comprehensively.According to the applications of functional adhesive materials in the field of oil and gas drilling and production at this stage,the key research directions of functional adhesive materials in the area of oil and gas drilling and production are proposed:(1)blending and modifying thermoplastic resins or designing curable thermoplastic resins to improve the bonding performance and pressure bearing capacity of adhesive lost circulation materials;(2)introducing low-cost adhesive groups and positive charge structures into polymers to reduce the cost of wellbore strengthening agents and improve their adhesion performance on the wellbore;(3)introducing thermally reversible covalent bond into thermosetting resin to prevent backflow of proppant and improve the compressive strength of adhesive proppant;(4)introducing thermally reversible covalent bonds into thermoplastic polymers to improve the temperature resistance,salt-resistance and water shutoff performance of adhesive water shutoff agents.

Application of HEMS cooling technology in deep mine heat hazard control

This paper mainly deals with the present situation, characteristics, and countermeasures of cooling in deep mines.Given existing problems in coal mines, a HEMS cooling technology is proposed and has been successfully applied in some mines.Because of long-term exploitation, shallow buried coal seams have become exhausted and most coal mines have had to exploit deep buried coal seams.With the increase in mining depth, the temperature of the surrounding rock also increases, resulting in ever increasing risks of heat hazard during mining operations.At present, coal mines in China can be divided into three groups, i.e., normal temperature mines, middle-to-high temperature mines and high temperature mines, based on our investigation into high temperature coal mines in four provinces and on in-situ studies of several typical mines.The principle of HEMS is to extract cold energy from mine water inrush.Based on the characteristics of strata temperature field and on differences in the amounts of mine water inrush in the Xuzhou mining area, we proposed three models for controlling heat hazard in deep mines:1) the Jiahe model with a moderate source of cold energy;2) the Sanhejian model with a shortage of source of cold energy and a geothermal anomaly and 3) the Zhangshuanglou model with plenty of source of cold energy.The cooling process of HEMS applied in deep coal mine are as follows:1) extract cold energy from mine water inrush to cool working faces;2) use the heat extracted by HEMS to supply heat to buildings and bath water to replace the use of a boiler, a useful energy saving and environmental protection measure.HEMS has been applied in the Jiahe and Sanhejian coal mines in Xuzhou, which enabled the temperature and humidity at the working faces to be well controlled.

Influence of droughts on remote villages in the karst region of Guizhou Province, China: Causes and control

Even though the precipitation is abundant in the Karst region of Guizhou Province, remote villages in this area frequently suffer severe droughts. This paper studied the causes of droughts in this region through field investigation and references collection. Based on the cause analysis, some suggestions were provided for hazard prevention and control from an engineering perspective. Besides occasional extreme weathers, the drought in this area is primarily caused by its unique geological structures of Karst plateau and underdeveloped agricultural techniques. Meanwhile, the vicious cycle between drought and poverty, which causes the deficiency of water conservancy facilities and hazard prevention awareness, is an important reason for the frequent occurrence of agricultural and socioeconomic drought. Considering the social and economic conditions of remote villages, the long-term control of drought can only be realized if current measures are capable of bring immediate effects and benefits. Therefore, the construction of well-planned and designed water conservancy system based on each village's natural and social conditions are the priority for current hazard prevention. Generally, the exploitation of subterranean river should be considered as the first choice to stabilize the water supply for remote villages. Meanwhile, the construction and improvement of micro water conservancy facilities, such as small water tank, small pond and so on, can effectively support the water providence during droughts as well.

Legislative Countermeasures for Preventing and Controlling Water Pollution in Water-deficient Regions

The shortage of water resources is severe in Beijing. The shortage of eco-environmental water and the sewage discharge over the environmental capacity are main bottlenecks that restrict the improvement of water environment. The reuse of wastewater could not only reduce the discharge of pollutants,but it could also increase the consumption of eco-environmental water. Therefore the reuse of wastewater is an important approach to improve the water environmental quality. Combined with the formulation process of Regulations of Beijing on Prevention and Control of Water Pollution,the current situations of prevention and control of water pollution in Beijing,the discharge of pollutant,water environmental quality,the population and economic development and water resources and so on were analyzed. And the bottlenecks that restricted the improvement of water environmental quality were found. And the necessity of solving the control of water pollution by reusing the wastewater and ensuring the consumption of eco-environmental water was analyzed from the perspective of the control of water pollution. And some legislative countermeasures were put forward,which provided new ideas for solving the problem of the prevention and control of water pollution and improving the water environmental quality. It was of important reference values for local governments（ especially water-deficient regions） to make relative polices or plans of water pollution control and water environmental protection.

Hydrogeological Hazards and Control Measures in Engineering Geological Exploration

For engineering geological investigation, hydrographic surveys are particularly important. By operating the equipment, relevant technicians analyze hydrogeological data around the project. A series of corresponding measures were taken to ensure the smooth completion of the project. However, due to the inadequate completion of hydrogeological survey work, it has great harm to the later stage of engineering work, and even will lead to the final failure of the project. Based on this, this paper explores the hazards and prevention measures of hydrogeology in engineering surveys.

Site Selection of Waste Slag Yard and Design of Protective Measures in Water Supply Project of Drawing from the Songhua River in Central Cities of Jilin

Water supply project of drawing from the Songhua River in central cities of Jilin is taken as research object.On the basis of analyzing project characteristics and natural conditions of the project area,site selection of waste slag yard of water diversion project and design of water and soil conservation measures are discussed.Rationality of site selection of waste slag yard and pertinence of prevention and control measures of water and soil loss in waste slag yard are analyzed,and comprehensive utilization of waste slag in large-scale production and construction projects is explored.

GEOLOGICAL HAZARDS AND THEIRS CONTROL

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Design of a water curtain to reduce accumulations of float coal dust in longwall returns

Accumulation of float coal dust(FCD)in underground mines is an explosion hazard that affects all underground coal mine workers.While this hazard is addressed by the application of rock dust,inadequate rock dusting practices can leave miners exposed to an explosion risk.Researchers at the National Institute for Occupational Safety and Health(NIOSH)have focused on developing a water curtain that removes FCD from the airstream,thereby reducing the buildup of FCD in mine airways.In this study,the number and spacing of the active sprays in the water curtain were varied to determine the optimal configuration to obtain peak knockdown efficiency(KE)while minimizing water consumption.

WATER POLLUTION IN CHINA:CURRENT STATUS, FUTURE TRENDS AND COUNTERMEASURES

Based on the statistical data related to water pollution in recent years, this paper firstly describes in detail the current status of water pollution and water quality in rivers, lakes, reservoirs, groundwater and coastal waters in China, then makes a comprehensive analysis on future trends of water pollution in China. The authors hold that the economic power, technology level and management level have determinative influences on the current status and future trends of water pollution. At last, this paper discusses briefly the policies and measures for preventing and controlling water pollution in the light of the national conditions.

The Occurrence Mechanism of Geological Disasters and Countermeasures in a Certain Area

In recent years, natural disasters in China have occurred frequently, especially large disasters such as earthquakes, floods and droughts, which have posed a serious threat to local public safety. In addition, the geological environment of local mountainous areas in China is complex and diverse, and climate change is large. Considering the dynamic coupling effect of rainfall conditions to stimulate geological disasters, this paper takes dynamic risk assessment technology as the guide, constructs a dynamic risk early warning model of geological disasters, establishes a prototype system, realizes dynamic risk assessment and emergency early warning of geological disasters at the regional level, and provides feasible technical support for targeted emergency disaster prevention. At the same time, the investigation and evaluation, mechanism research and monitoring and early warning related to the comprehensive prevention and control of geological disasters are important tasks that cannot be ignored, an important link in the emergency response system for geological disasters, and a key stage process to guide scientific disaster prevention. On the basis of exploring the mechanism and catastrophic effect of rainfall to stimulate landslides and mudslides, we will carry out in-depth research on disaster prevention countermeasures such as systematic engineering disposal, monitoring and early warning.

基于主量元素地球化学的岩屑层位源解析

近年来,岩屑录井在“华北型”煤田底板灰岩层注浆加固工程中发挥了重要作用。然而,现有的岩屑录井仅停留在颜色、颗粒大小及形貌特征等物理指标的识别上,难以精准判层,钻孔设计“顺层率”难以保障,制约着底板灰岩水害区域治理效果。基于石炭纪太原组薄层灰岩及其碎屑岩夹层的元素地球化学差异特点,选取淮北煤田桃园煤矿为研究区,对太原组上段薄层灰岩L_(1)灰~L_(4)灰地层(注浆治理目的层为L_(3)灰)垂直钻孔岩心进行取样,利用X射线荧光光谱仪(XRF)定量测定了薄层灰岩及其夹层的主量元素背景值,通过聚类分析、因子分析等数理统计手段建立薄层灰岩主量元素地球化学识别模式;同时对地面定向钻水平分支孔岩屑同样开展主量元素测试,并基于已建立的地球化学识别模式进行岩屑层位源解析以及识别模式验证。结果显示:高CaO丰度、烧失量(LOI)可以作为注浆加固改造目的层L_(3)灰的特征指标,MgO(0.5%±)、MnO(0.03%±)、P_(2)O_(5)(0.08%±)丰度可作为注浆目的层上覆标志层J3的识别指标;聚类分析识别模式可有效区分太原组一灰~三灰(L_(1)灰~L_(3)灰);以元素因子得分建立的识别模式可以将太原组碎屑岩夹层与薄层灰岩进行有效区分;以岩样地球化学背景值运行判别模型得到的Fisher判别方程对注浆目的层L_(3)灰岩屑来源解析的准确率为100%。基于上述认识,论证了以确保设计“顺层率”为目标的水平分支孔岩屑地球化学源解析方法应用之可行性,进而提出了一种地面定向钻“顺层率”控制技术方案。本研究基于元素地球化学理论,对地面定向钻岩屑携带的特征地球化学信息进行了目的层层位辨识,在现场快速定量测试技术手段的支持下,可为解决华北型煤田底板灰岩水害区域注浆改造顺层难题提供了新的思路。

采场全生命周期的矿压危害事件知识图谱表示方法研究

知识图谱是认知智能研究不可或缺的组成部分。针对采场矿压危害事件传统分析方法对煤矿开采过程中应力时空演化过程及隐患演化与风险防控关系等表达存在不足的问题,本文基于采场全生命周期提出一种采场矿压危害事件知识图谱表示方法:首先,从地质灾害的角度,分析采场应力及分布的动态特性,对矿压地质灾害中的各节点进行动态关联,提出顾及时空过程的采场矿压地质灾害知识图谱表示方法。其次,从事故的角度,分析采场矿压事故隐患演化与风险防控过程,将隐患耦合演化与防治措施融入知识图谱表示模型中。最后,运用Neo4j构建矿压危害事件知识图谱。结果表明:依据该表示方法构建的知识图谱,不仅刻画了灾害事件中不同对象的时空演化过程,还描述了隐患耦合演化过程以及对应的风险防控措施,为采场矿压危害的防治提供了智能研究途径。

侏罗系宝塔山砂岩突水风险预测及限制边界疏降技术

内蒙古上海庙矿区新上海一号煤矿发生国内首次也是目前唯一的侏罗系煤层开采底板宝塔山砂岩突水淹井事故;开展了侏罗系煤层开采底板强富水宝塔山砂岩突水危险性评价方法和防控技术的研究工作。首先,明确了“11·25”事故的突水水源为侏罗系延安组下部的宝塔山砂岩含水层,且煤层与底板宝塔山砂岩之间隔水层具有强度低、软化系数小、胶结性差的特点,属地质软岩。其次,以“含水层厚度、含水层富水性、含水层渗透性、含水层水压力及18煤底板隔水层有效厚度”为主要指标建立突水评价体系,将宝塔山砂岩含水层突水危险性分区被划分为安全区(32.21%)、威胁区(37.53%)及危险区(30.26%)三种类型,并通过实例验证了评价模型的准确性。最后,结合底板隔水层工程地质特性,分析采用“断层注浆形成局部限制边界+群孔疏降”的方法防控宝塔山砂岩突水。设定“疏放水开始至1号钻场退出疏放水工作、2号、3号和4号钻场持续进行疏放水工作至3号钻场退出、2号和4号钻场持续进行疏放水工作至模型补排平衡”的疏降方案。依据规范得出注浆后最大帷幕渗透系数为2×10^(-2) m/d,当断层注浆后帷幕渗透系数为2×10^(-2)~2×10^(-8) m/d时,疏放水量为402万~347.8万m^(3),安全区占矿区的比例为43.34%~67.37%。结合注浆成本、疏放水量和安全性,帷幕渗透系数为2×10^(-4) m/d时即可有效保证矿井安全生产和技术经济效益。断层注浆局部限制边界+疏放水联合技可有效防控宝塔山砂岩水害,研究工作对我国西部侏罗纪煤田开发底板水防治具有重要意义和工程实践价值。

考虑采动效应的闭坑矿井水硫酸盐污染规律

高硫煤矿闭坑后成为埋藏在地表以下深部的产酸污染场,对相邻含水层和周边环境造成了潜在危害,且因采动效应影响和矿井空间分布复杂导致相邻含水层的污染过程与污染程度评价困难。以某闭坑矿区为研究对象,选取SO_(4)^(2-)作为特征污染物,考虑多煤层采动裂隙对含水层结构的破坏影响,运用数值模拟技术对闭坑矿区酸性矿井水中SO_(4)^(2-)污染迁移特征进行研究,并分析流体扩散系数对含水层污染物运移的影响。结果表明:SO_(4)^(2-)在二叠系童子岩组砂岩含水层中水平迁移面积随时间增大而增大,增大速率逐渐减小,垂向渗透系数扩大10倍,空间变异性增强;闭坑5、10、15a后,最大水平迁移距离分别为215、414、612m,最大垂向迁移距离分别达到50、65、70m;而扩散系数越大,产酸时间越长,SO_(4)^(2-)迁移距离和污染范围将随之增大,相较于水平方向,垂向上SO_(4)^(2-)浓度变化对扩散系数的敏感度更高。基于模拟结果,结合闭坑矿区实际条件,针对性提出了“源头减量-过程阻断-末端治理”的综合防控与治理方案。研究结果将为该闭坑煤矿酸性矿井水污染治理与防控提供理论基础,也为其他同类矿井提供科学借鉴。