Engineering Commons^™

Effect Of Clay Content On Shear Strength Of Loess, Wang Li, Li Xi'an, Hong Bo, Du Shaoshao, Zhang Hangbo, Zhao Ning

Coal Geology & Exploration

The experimental research about effect of different clay content on shear strength of loess was carried out to reveal the influence of clay content on shear strength and its microscopic mechanism, and then a scientific basis for engineering practice of loess was provided. Self-made wet sieve device under negative pressure was applied to screen loess samples with different clay content. Different clay content of the loess samples were made to the same dry density, but with different moisture content using static pressure method, and then were taken direct shear test. The results show that with the increase of moisture content, …

Feasibility Test Of Roof Resistivity Monitoring For Super-High Mining Face, Lu Jingjin, Li Deshan, Wang Bingchun

Coal Geology & Exploration

The failure of roof overburden is one of the main reasons for water inrush in mining working face. Roof resistivity monitoring by mine electrical method can be used to detect overburden failure dynamically. However, roof resistivity monitoring for super-high mining face has many problems, such as audio electromagnetic signal by conventional methods is difficult to penetrate through wide working face, burying of roof monitoring electrodes is difficult, monitoring electrode in the roof of air return lane is hard to protect, and so on. In order to solving these problems, feasibility study of roof resistivity monitoring for super-high mining face is …

Experimental Study On The Influence Of Well Inclination Angle Of Coalbed Methane Well On The Cementation Strength Of Cement-Formation Interface, Gu Jun, Li Linwei, Sun Dexing

Coal Geology & Exploration

In order to control the problem of water channeling in the process of coalbed methane(CBM) production, based on the self-designed test device and method, the test data of the shear strength at cement-aquiclude interface (CAI) is obtained under the conditions of well inclination of 0°, 30°, 60° and 90°. The mechanism of the influence of inclination angle on the shear strength at CAI is analyzed. The results show that the shear strength at CAI decreases with the increase of the inclination angle. The reason is that as the inclination angle increases, the upper part of the mud cake ring becomes …

Reasonable Length Of Working Face 11-101 During Mining Above Confined Aquifer In Tuanbai Mine, Li Gang, Zhang Kai, Su Junhui, Wang Jinbo

Coal Geology & Exploration

The working face 11-101 of Tuanbai coal mine in Huozhou, Shanxi Province is exploited above aquifer. In order to prevent floor water inrush accidents during mining, research combination of elasto-plastic theory, on-site measurement and numerical simulation was carried out to analyze the development rule of failure depth of the floor, then the reasonable length of the mining face under this condition was determined. The result shows that with the advancement of working face, the bottom plate of lagging working face is stretched and destroyed at about 6 m behind the lagging working face, and the bottom plate has a wedge …

Development Of Data Acquisition And Control Software For Seismic Monitoring With Mining, Duan Jianhua, Wang Yunhong, Wang Baoli

Coal Geology & Exploration

Seismic monitoring with mining can continuously detect and real-time predict geological anomalies in front of work, it has become a research hotspot in recent years, but at present, there is no equipment that can carry out seismic monitoring with mining in coal mine.Therefore, the development of seismic monitoring equipment with mining has become a top priority. In order to solve this problem, based on the MFC development framework, a set of seismic monitoring data acquisition software is developed. A three-month joint survey was carried out indoors and outdoors, and a three-month comprehensive trial operation was carried out in Yanjiao Coal …

Experiment On Methane Displacement In Coalbed By Supercritical Carbon Dioxide, Wu Di, Liu Xueying, Sun Keming, Xin Liwei, Miao Feng

Coal Geology & Exploration

Using self-made experimental system, experiments were performed on coal samples to study supercritical CO₂ seepage, adsorption and CH₄ displacement by supercritical CO₂. Experimental results show that permeability and adsorption of supercritical CO₂ in coal increase with CO₂ pressures. Pressures and temperatures of CO₂ influence the values of displaced CH₄. Values of displaced CH₄ increase by average 0.076 cm³/g and sweep efficiency rises by 17%-23% with the CO₂ pressure increasing from 8 MPa to 12 MPa, while displacement volume decreases linearly. With the temperature rising by 10℃, sweep …

The Matching Of Gas Production Curve Characteristic And Reservoir Conditions In Vertical Coalbed Methane Wells, Han Wenlong, Wang Yanbin, Liu Du, Chang Hong, Ding Tao

Coal Geology & Exploration

The matching of coalbed methane(CBM) production curve type and geological conditions directly affects the gas production. Based on dividing gas production curves types of vertical CBM wells in the southern block of Shizhuang in Qinshui basin over 4 years, the characteristics of gas production curve were analyzed. The matching of gas production curve with reservoir parameters was further analyzed. The paper discovered and divided the gas production curve into four types:type of fast rising of single peak, type of stable rising of single peak, bimodal type of being low later and bimodal type of being high later. The original permeability, …

The Seepage Characteristics Of A Single Well Dewatering From An Unconfined Aquifer Bottom, Li Yang, Wang Wenxue, Xiao Hang, Sun Yi, Wang Yun, Di Mengna

Coal Geology & Exploration

Dewatering from an aquifer bottom for drain and depressurization is one common method to ensure safety mining. This method is significantly different from pumping from the ground. In order to study the seepage characteristics of the dewatering hole(well), the seepage characteristics of a single well dewatering from an unconfined aquifer bottom was taken as an example and studied using numerical simulation method. The results show that when l_w<l_c, the pore water pressure above the dewatering well is greater than zero, which presents the rule of increasing first then decreasing from bottom to top, and the seepage …

Quantitative Quality Evaluation Of Seismic-While-Mining Data, Qin Si, Cui Weixiong, Wang Wei

Coal Geology & Exploration

A seismic-while-mining(SWM) monitoring system laid in a working face of an underground coalmine will continuously generate tremendous amount of SWM data. When a coalmine cutting machine cuts coal seam actively, the SWM data will be of high correlation, and when it is not, the SWM data will be of low correlation or even no correlation at all. Based on this characteristic, a method for automatically and quantitatively evaluating the quality of SWM data was proposed. Using this method to process SWM data from a coal mine in Inner Mongolia, the result showed that this method can recognize the correlation peak …

Study On Noise Attenuation Of Seismic While Mining, Liu Qiang

Coal Geology & Exploration

In view of the closure of the environments and the high requirements of safe production of underground coal mine, the explosive source has many limitations in the operation of seismic exploration of coal mine, and the coal shearer as the source can avoid many inherent shortcomings of the source of explosives, has the advantage of real-time detection of the internal structure and the stress of the working face without affecting the normal operation of the mining face. However, as the energy generated by the shearer is much smaller than that of the explosive source, the quality of the collected signal …

Development And Application Of Software In Seismic While Mining Data Processing, Wang Baoli

Coal Geology & Exploration

The seismic while mining detection technology with coal cutter as seismic source in coal face is the key to accurately know the geological conditions of mining, improve the detection accuracy of geological anomaly structure in coal face, and realize unmanned intelligent mining or with few people. It has broad application prospects.The conventional seismic data processing software can not meet the requirements of real-time, continuous and large data volume for seismic while mining data. By analyzing the requirement of seismic while mining detection technology for data processing software(SWM), a framework of hierarchical and multi-task data processing software is proposed. The components …

Auxiliary Outburst Prevention Techniques By Surface Pre-Drainage For Coalbed Exposed In Tunnel And Mine Shaft, Zhang Dongliang

Coal Geology & Exploration

How to expose an outburst-prone coal seam safely and efficiently in tunnel and mine shaft is always a subject to study continuously in outburst prevention, surface coalbed gas pre-drainage is an effective approaches for outburst prevention. Based on the analysis of outburst mechanism in tunnel and mine shaft and the core task of outburst prevention, the characteristics and adaptability of the outburst prevention techniques by surface pre-drainage are studied. Practical engineering application shows that the gas content and pressure in coal exposure area can be effectively reduced using surface pre-drainage well by cavern completion or hydraulic fracturing, the stress or …

Study On Sediment Environment And Rock Mechanics Characteristics Of The Delta Plain Of Jurassic Coalfield In Northern Shaanxi, Wang Haijun, Ma Liang

Coal Geology & Exploration

Delta plain sedimentary environment is one of the coal-forming environments of the coal resources of Jurassic coalfield in northern Shaanxi. In order to get the rock mechanics parameters and characteristics of coal seam roof in different environments and to further investigate the relationship between the sedimentary environments and the rock mechanics characteristics, firstly from the analysis of the regional sedimentary environments, then by using techniques such as accurate core description, sedimentary structural analysis, facies analysis of geophysical logging, the microfacies were recognized, the sedimentary microfacies types of roof and their combination characteristics were classified. Later, rock samples of different lithology …

Application Of Sec Dynamic Reserves Evaluation Method In Coalbed Methane Field: A Case From Hancheng Block In Ordos Basin, Yi Wei, Xiong Xianyue, Cao Yimin, Ding Rong

Coal Geology & Exploration

At present, all the SEC reserves evaluation of coalbed methane fields uses dynamic assessment methods. In the process of evaluation, the parameters and calculation results are various. In order to solve this problem, this paper takes the Hancheng block in Ordos basin as an example, a series of evaluation methods adapted to the production characteristics of coalbed methane have been comprehensively applied, optimizing various parameters, and summarizing the law of decline. The results show that geological units are divided according to tectonic conditions, and on this basis, evaluation units are divided according to development effect, which can objectively and reasonably …

Diffusion Ability Of Contaminants Of Coal Gangue Leachate In Geosynthetic Clay Liners, Dong Xingling, Dong Shuning, Zhou Zhenfang, Wang Qiangmin, Liu Ji

Coal Geology & Exploration

To verify the feasibility of geosynthetic clay liners(GCL) as liners material for coal gangue impoundment, diffusion tests were conducted with vertical double reservoir method to determine the diffusion ability of heavy metals(Zn²⁺、Mn²⁺) and sulfate from coal gangue leachate in GCL-S(Sodium-activated bentonite), and POLLUTE V7 based on finite layer method was used to draw the fitting curve of pollutant changing with time in the diffusion device, which calculated the diffusion coefficient of contaminants in GCL. The data show that the diffusion coefficient in GCL was lower than that in compacted clay liners, so GCL could control the …

Occurrence Regularity Of Uppermost Minable Coal Seams And Their Harmful Level Of Mining In Yushen Mining Area, Li Zhixue, Shen Xiaolong, Li Mingpei, Wang Hongsheng

Coal Geology & Exploration

In order to study the occurrence regularity of uppermost mining coal seams and the damage degree of Salawusu Formation aquifer caused by mining in Yushen mining area, occurrence characteristics of the uppermost mining coal seams was analyzed, and spatial distribution law and combination of the uppermost mining coal seams overlying strata, the development law of the water flowing fractured zone based on the ratio of rock and loading thickness and mining height, and the damage degree of the Salawusu Formation aquifer caused by coal seam mining. The damage degree of the Salawusu Formation aquifer was divided into four kinds of …

Detection Electric Field Control Strategy For Advanced Scanning Detection Of Focusing Multipoint Current Sources In Coal Mine Roadway, Liu Zhimin, Meng Cairu, Li Bing, Han Lei, Pan Yue

Coal Geology & Exploration

In order to realize the effective detection of electric field focusing depth and deflection angle scanning of focusing multipoint current sources in coal mine roadway, and accurately grasp its variation, according to the advanced scanning detection mechanism, Gauss theorem and two different methods were used to solve the integration process and derive the electric field line equation of a uniformly charged linear electrode with finite length. The electric field line equation of coplanar multi-electrode layout is induced and deduced through using its spatial distribution symmetry. By changing focusing shielding current ratio coefficient, this paper calculates the boundary line equation of …

Development Of High Temperature Borehole Inclinometer, Qu Zhaogui, Gong Mingmao, Zhou Ce, Wang Guangzhai

Coal Geology & Exploration

In the detection of high-temperature and high-pressure dry heat rock drilling location trajectory, the instrument has some problems, such as poor performance, poor stability, low measurement accuracy and large energy consumption. A set of high temperature borehole inclining device is designed to solve the problem of high temperature and high pressure measurement deviation and temperature measurement. Adopt high temperature resistant components, design control and measurement circuit. Automatic intermittent power supply is adopted to reduce heat dissipation and power consumption. The design of heat preservation pipe and pressure detection pipe is carried out by using ANSYS finite element software to conduct …

Application Of Wire Line Coring Technique In Overburden Drilling, Li Baijun, Zou Run, Guo Chao

Coal Geology & Exploration

In order to improve the drilling efficiency of two oil and gas geological survey wells "Jitaodi 1" and "Ji Bai Di 1" in Baicheng area of Jilin Province, wireline coring technique was applied in overburden drilling. Based on the lithological characteristics of the drilled strata, combined with the technological characteristics of core extraction by lifting the drill pipe and wireline core extraction, by designing the bit, drilling flushing fluid and by improving drilling procedure parameters, drilling tool nozzle flow channel, the wireline coring drilling method has been successfully applied in drilling overburden strata(about 1 100 m thick). Compare with the …

Water In South Dakota Stakeholder Guided Strategies For Moving Forward, Rachel Mcdaniel, John Mcmaine, David Kringen

SDWRI Publications and Reports

The 2017 Eastern South Dakota Water Conference included a stakeholder working session that resulted in over 350 comments. This paper reflects the challenges, goals and action items pertaining to South Dakota’s water resources as identified by the state’s diverse stakeholders.

Prioritizing Rehabilitation Of Sanitary Sewers In Pinellas County, Fl, Jesse T. Hillman

USF Tampa Graduate Theses and Dissertations

Following large rain events, extraneous freshwater contributions known as inflow and infiltration (I/I) bypass the storm sewer and enter the sanitary sewer system. In areas with a high water table, like Pinellas County and the surrounding Tampa Bay area, a majority of the wastewater infrastructure is submerged year round exacerbating the rate of groundwater infiltration. This excess flow overloads the existing wastewater infrastructure leading to sanitary sewer overflows (SSOs). These SSOs result in serious problems for municipalities and utilities across the country.

This study was performed in order to assist Pinellas County Utilities in rehabilitating their southern sewer system. To …

Analyzing The Efficiency Of Horizontal Photovoltaic Cells In Various Climate Regions, Parker A. Hines, Torrey J. Wagner, Clay M. Koschnick, Steven J. Schuldt

Faculty Publications

This research presents the development of linear regression models to predict horizontal photovoltaic power output. We collected a dataset from 14 global Department of Defense (DoD) installations over a timeframe of one year using an experimental apparatus, resulting in 24,179 usable data points. We developed a linear model to predict power output, which incorporated site-specific weather and geographical characteristics, along with Köppen-Geiger climate classifications in order to determine the effect of adding climate to the model. After performing a Wald test between the full model and a reduced model without Köppen-Geiger climate variables, it was determined that including Köppen-Geiger climate …

Fouling And Aging In Membrane Filtration : Hybrid Afm-Based Characterization, Modelling And Reactive Membrane Design, Wanyi Fu

Dissertations

Membrane filtration has been extensively used in water and wastewater treatment, desalination, dairy making, and biomass/water separation. However, membrane fouling, aging and insufficient removal efficiency for dissolved organic matters remain major challenges for wider industrial applications. In order to tackle these challenges, this doctoral dissertation investigates mechanisms of membrane fouling and development of antifouling membrane filtration technologies. Specifically, four major research areas are explored: (i) nanoscale physicochemical characterization of the chemically modified polymeric membranes; (ii) quantitative modelling between membrane properties and membrane fouling and defouling kinetics; (iii) development of quantitative structure-activity relationships for membranes that undergo thermal and chemical aging …

Meeting 2030 Primary Energy And Economic Growth Goals: Mission Impossible?, Matthew Kuperus Heun, Paul E. Brockway

University Faculty Publications and Creative Works

To meet climate change mitigation objectives, international institutions have adopted targets aimed at reducing or ending growth of primary energy consumption. Simultaneously, continued economic growth is forecasted to meet human development goals. Together, declining energy consumption and rising gross domestic product (GDP) is called “absolute decoupling.” However, absolute decoupling is unprecedented for the world economy as a whole (since at least 1971). Is absolute decoupling “Mission impossible?” Given the high stakes, we need a clearer understanding of the extent of future energy–GDP decoupling. To gain that understanding, we perform societal exergy analyses using a novel Physical Supply Use Table framework …

Statistical Viability Analysis Of United States Air Force Estimating Cost Factor For Sustainable Construction, Philip A. Ramsey, Diedrich Prigge, Torrey J. Wagner, Alfred E. Thal Jr.

Faculty Publications

Varying legislation and executive orders coupled with needs for energy resiliency have led the United States Air Force (USAF) to pursue sustainable construction. However, the limited understanding of initial costs to implement these changes have contributed to poor project cost estimating, resulting in 62 percent of USAF projects experiencing more than 5 percent cost growth. After reviewing 1628 USAF Military Construction (MILCON) construction projects in 922 category codes (CATCODEs), a twotailed t-test for populations with unequal variance was accomplished on the final normalized contract cost for 340 projects in 16 CATCODEs executed between 2002 and 2017. This analysis provides a …

An In-Situ Study Of The Aqueous Speciation Of Uranium (Vi) Under Hydrothermal Conditions, Diwash Dhakal

Graduate Theses/Dissertations

Rigorous study of the speciation distribution of uranyl-chloride bearing solutions under hydrothermal conditions is important to understand the transport mechanism of uranium underground, which is of uttermost interest to parties studying the geological uranium deposits and those studying the possibilities of geological repositories for spent nuclear waste. I report an in-situ Raman spectroscopic study of the speciation distribution of aqueous uranyl-chloride complexes upto 500°C conducted using a HDAC as the high PT spectroscopic cell. The samples studied contained the species UO₂²⁺, UO₂Cl⁺, UO₂Cl₂⁰ and UO₂Cl₃^{- …}

Using Numerical Models Of Dewatering At Coal Ash Impoundments To Understand Cost And Schedule, Peter Bell, Joel Thompson, Don Fuller

World of Coal Ash Proceedings

No abstract provided.

Investigating Ccr Units And Evaluating The Physical Properties Of Ponded Ccr, David Skeggs, Zahra Aghazadeh, Rachel Combs

World of Coal Ash Proceedings

No abstract provided.

Demonstration Of “No Migration” Alternative Performance Standard For Ccr Facilities In Arid To Semi- Arid Regions Using Unsaturated Zone Modeling, James Aiken, Katy Lindstom

World of Coal Ash Proceedings

No abstract provided.

Coal Combustion Residuals Management Using Geotextile Containers- Considerations For Various Options, Randall Wilcox, Gregg Lebster, Bryan Hamilton, Thomas Stephens

World of Coal Ash Proceedings

No abstract provided.