Experimental Study On Mesoscopic Damage And Fragmentation Characteristics Of Hard Rock Under Repeated Particle Impacts,
2023
State Key Laboratory of Geomechanics and Geotechnical Engineering, Institute of Rock and Soil Mechanics, Chinese Academy of Sciences, Wuhan, Hubei 430071, China
Experimental Study On Mesoscopic Damage And Fragmentation Characteristics Of Hard Rock Under Repeated Particle Impacts, Ming-He Ju, Ze-Jun Tao, Xiao-Feng Li, Li-Yuan Yu, Li-Jie Jiang, Xiao-Zhao Li
Rock and Soil Mechanics
Particle impact, a new drilling technology, has been applied in drilling and gas and oil exploitation. Also, it is considerably promising as an assisting rock-breaking method for the excavation of tunnels in extremely hard rocks. In this paper, an experimental study was conducted to investigate the effects of particle impact number, particle strength, and particle impact velocity on the damage and fragmentation characteristics of surface impact crater in extremely hard granite. The three-dimensional morphology, rock fragments, and mineral fragmentation properties in the impact crater were quantitatively analyzed. The results indicate that the maximum depth of the impact crater increases in …
Grouting Test And Reinforcement Mechanism Analysis Of Rock With Single Penetrated Fracture Surface,
2023
School of Resource & Environment and Safety Engineering, Hunan University of Science and Technology, Xiangtan, Hunan 411201, China
Grouting Test And Reinforcement Mechanism Analysis Of Rock With Single Penetrated Fracture Surface, Yong-Jian Zhu, Heng Ren, Ping Wang, Peng Li, Xi-Zhi Wang, Ming-Xing Wei
Rock and Soil Mechanics
For the problem that how the grouting reinforcement of a single penetrated structural plane affects the bearing capacity of surrounding rock, an approach of rock samples preparation with single penetrated fracture surface is proposed firstly, and the rock samples are injected with ultrafine cement and epoxy resin, respectively. Then, the strength and deformation characteristics of the consolidated body under uniaxial (triaxial) compression are investigated with the RMT-150C experimental system. Finally, the micro consolidation mechanism of structural plane grouting is revealed using theoretical analysis and electron microscope scanning. It is found that the fracture surface generated under the triaxial loading-unloading condition …
Evaluation Of Cement Stabilized Recycled Asphalt Pavement/Lateritic Soil Blends For Soft Soil Improvement,
2023
School of Civil Engineering, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand
Evaluation Of Cement Stabilized Recycled Asphalt Pavement/Lateritic Soil Blends For Soft Soil Improvement, Suksan Aniroot, Horpibulsuk Suksun
Rock and Soil Mechanics
This research evaluates the potential of cement stabilized recycled asphalt pavement (RAP)/marginal lateritic soil blends as stone column aggregate instead of the traditional quarry aggregate. The undrained shear response of the blended materials at various RAP replacement ratios and effective confining pressures are investigated. The RAP replacement ratios were 10%, 30% and 50% by dry weight and ordinary Portland cement contents were 1% and 3%. It was evident that RAP replacement increased large particles and meanwhile reduced fines particles; hence the increased compactibility. Under applied effective stress lower than pre-consolidation pressure, RAP-soil blends exhibited strain-hardening behavior associated with decreased pore …
Experimental Study Of Micp-Treated Sand Enhanced By Pozzolan,
2023
Rock and Soil Mechanics
Experimental Study Of Micp-Treated Sand Enhanced By Pozzolan, Yu Xiong, Hua-Feng Deng, Jian-Lin Li, Lei Cheng, Wen-Xi Zhu
Rock and Soil Mechanics
In order to improve the reinforcement effect of microbially induced calcium carbonate precipitation (MICP) technology on sand, the test of MICP-treated sand reinforced by pozzolan was designed and carried out considering the porous structure and activity characteristics of pozzolan. The enhancement effect and enhancement mechanism of pozzolan on the MICP-treated sand were systematically analyzed by integrating macroscopic physical and mechanical tests and microscopic tests. The results showed that: 1) Pozzolan could significantly improve the bacteria fixation rate and cementation material production in the process of sand microbial reinforcement, and the optimal amount of pozzolan content was around 10%, which increased …
Mineralogical Evidence Of Alkaline Corrosion Of Montmorillonite In Gmz Bentonite,
2023
Rock and Soil Mechanics
Mineralogical Evidence Of Alkaline Corrosion Of Montmorillonite In Gmz Bentonite, Yan-Mei Tong, Hu-Yuan Zhang, Guang-Ping Zhou, Xiao-Ya Li
Rock and Soil Mechanics
During the operation of underground repository of high-level radioactive waste, the highly alkaline solution generated by groundwater corroding lining concrete will diffuse into the bentonite buffer barrier, resulting in the degradation of barrier property. The KOH solution with different pH values was used to simulate the alkaline solution, and a one-year contact diffusion test at room temperature was conducted. Then, X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), scanning electron microscope (SEM) and energy dispersive spectrometry (EDS) were performed to investigate the effect of slow diffusion on the mineralogy of bentonite. The XRF test results show that when the pH of …
Rock Cutting Characteristics With Single Pick And Prediction Of Cutting Force Based On Force Chain,
2023
National Engineering Laboratory of Coal Mining Machinery and Equipment, Taiyuan, Shanxi 030032, China
Rock Cutting Characteristics With Single Pick And Prediction Of Cutting Force Based On Force Chain, Lei Dong, Hua Zhang, Ji-Shuang L, Rui-Min Shi
Rock and Soil Mechanics
The pick is the main load-bearing object of the mining machinery for cutting coal. Prediction of the cutting force from the working condition is essential to reduce the wear of the pick. The rock was considered as a granular material for single pick cutting simulation using the particle flow code (PFC2D). The influence of the contact state on the cutting force of the single pick was discussed based on the characteristics of the force chain between particles during rock cutting. The cutting force test was carried out with a single pick cutting test equipment. The variation laws of the cutting …
Multivariate Experimental Study On Soybean Urease Induced Calcium Carbonate Precipitation,
2023
Jiangxi Province Key Laboratory of Hydraulic & Civil Engineering Infrastructure Security, Nanchang, Jiangxi 330099, China
Multivariate Experimental Study On Soybean Urease Induced Calcium Carbonate Precipitation, Meng Cui, Xiao Fu, Jun-Jie Zheng, Su-Ying L, Hui-Hui Xiong, Chen Zeng, Shang-Yu Han
Rock and Soil Mechanics
The plant-derived enzyme induced calcium carbonate precipitation (EICP) can significantly improve the engineering mechanical properties of sand. However, there is no specification for choosing the parameter value in the specific operation, and the solidification effect needs to be improved. Based on soybean urease, the effects of temperature, urease concentration, urea concentration, calcium concentration, pH value, calcium source type and other variables on urease activity and calcium carbonate precipitation were studied, and the SEM and XRD tests on precipitated calcium carbonate crystals were carried out. On this basis, the unconfined compressive strength and solidification effect of soybean urease-solidified sand were tested. …
Laboratory Investigation On The Effect Of Waste Plastic Bottles Filled With Soil As Transverse Members On Pullout Resistance Of Steel Strip For Reinforcement Fine Sand,
2023
Ph. D., Department of Civil Engineering, Technical and Vocational University (TVU), Tehran, Iran and Department of Civil Engineering, Arak Branch, Islamic Azad University, Arak, Iran
Laboratory Investigation On The Effect Of Waste Plastic Bottles Filled With Soil As Transverse Members On Pullout Resistance Of Steel Strip For Reinforcement Fine Sand, Beyranvand Alireza, Hamid Lajevardi Seyed, Ghazavi Mahmoud, Mohammad Mirhosseini Seyed
Rock and Soil Mechanics
The aim of this study is to investigate the feasibility of utilizing the waste plastic bottles filled with soil as the transverse element attached to the steel stripe in the Mechanically Stabilized Earth Walls (MSEWs). Transverse members of reinforcement have a major effect on increasing the pullout resistance. This system is comprised of a steel stripe as a longitudinal member and waste plastic bottles filled with soil as transverse members attached to it. To understand this, pullout tests were conducted on one steel strip and seven steel stripes with one to seven bottles. More than 18 laboratory large-scale pullout tests …
Strength And Damage Characteristics Of Tailings Filling Body With Different Particle Size Distributions,
2023
School of Civil and Resources Engineering, University of Science and Technology Beijing, Beijing 100083, China
Strength And Damage Characteristics Of Tailings Filling Body With Different Particle Size Distributions, Ai-Bing Jin, Jie Wang, Shuai-Jun Chen, Hai Li
Rock and Soil Mechanics
To explore the influence of tailings particle size distribution on strength and damage characteristics of filling body, uniaxial compression, scanning electron microscopy, and digital image correlation (DIC) tests were carried out on the filling body composed of ultrafine tailings (median particle size D50=10.1 m), fine tailings (D50=37.1 m), and coarse tailings (D50=121.31 m), and the strength and microstructure characteristics were analyzed. Based on the cusp mutation theory, the damage identification index of the filling body was established using wavelet packet technology, and the damage characteristics of the filling body were quantitatively analyzed. The results reveal that the strength and elastic …
A New Method For Evaluating Rock Joint Roughness Based On Power Spectral Density,
2023
Rock and Soil Mechanics
A New Method For Evaluating Rock Joint Roughness Based On Power Spectral Density, Chuan-Qing Zhang, Yu-Hang Guo, Jin-Shun Xu, Ning Liu, Qi-Ming Xie, Guo-Jian Cui, Hui Zhou
Rock and Soil Mechanics
To further improve accuracy and reliability of describing the roughness feature of the structural plane, and more comprehensively reflect influences of the morphological differences, the fluctuation of the profile was decomposed into three principal characteristics: amplitude, inclination, and curvature, which represent the change characteristics of height, angle, and bending of the profile. The data of the three characteristics were obtained by 10 standard profiles established by Barton. And the distribution curves of the three characteristics were analyzed. Then, the power spectral density (PSD), which can well describe the microscopic morphology, was used to analyze the spectral characteristics of amplitude, inclination …
Stability Analysis Of Shield Tunnel Face Considering Spatial Variability Of Hydraulic Parameters,
2023
Wuhu Surveying and Mapping Design Institute Co., Ltd., Wuhu, Anhui 241000, China
Stability Analysis Of Shield Tunnel Face Considering Spatial Variability Of Hydraulic Parameters, Shuai Yuan, De-Wang Feng, Sen-Hao Zhang, Yun-Peng Xing, Zun-Qi Ke
Rock and Soil Mechanics
The shield method is commonly employed in the construction of urban subways, and the stability of the excavation surface is extremely important for the safety of tunnel construction. When constructing tunnels in submerged or water-rich strata, the seepage force is a key factor affecting the ultimate support force of excavation faces. Uncertainty of natural geotechnical material hydraulic parameters significantly impacts the seepage force near the face. Based on the classic limit analysis and the random field theory, the principle of effective stress in saturated soil is introduced, and the stochastic numerical limit analysis method considering the influence of pore water …
A Rapid Determination Method Of Hydraulic Conductivity In Full Suction Range,
2023
Rock and Soil Mechanics
A Rapid Determination Method Of Hydraulic Conductivity In Full Suction Range, A-Qiang Liu, Xu Li, Yan Liu, Zhi-Yuan Zhang
Rock and Soil Mechanics
The hydraulic conductivity function of unsaturated soil spans several orders of magnitude. Traditional measurement methods often take several months, and it is difficult to measure the hydraulic conductivity in the full suction range. In order to realize the rapid measurement of hydraulic conductivity in the full suction range, the wetting front advancing method is combined with the instantaneous profile method (here referred to as the combined determination method) in this study. A self-developed soil column infiltration device was used to measure the hydraulic conductivity of Qinghai silty clay in the full suction range under different dry densities. The test results …
Soil Moisture And Geomorphologic Data For Use In Dynamic And Forecastable Landslide Hazard Analyses In Eastern Kentucky,
2023
University of Kentucky
Soil Moisture And Geomorphologic Data For Use In Dynamic And Forecastable Landslide Hazard Analyses In Eastern Kentucky, Daniel M. Francis, L. Sebastian Bryson
Civil Engineering Research Data
These data are the geomorphologic and land information system-based soil moisture estimates from assimilation of NASA SMAP satellite-based observations and NOAH 3.6 Land Surface Model estimates over known landslides in Eastern Kentucky. Additionally Long Short-Term Memory Recurrent Neural Network and logistic regression machine learning codes, as well as an Application programming interface code are included. Finally, in-situ data from Eastern Kentucky is included.
Development And Testing Of A Low Mass Vibratory Lunar Compactor,
2023
Michigan Technological University
Development And Testing Of A Low Mass Vibratory Lunar Compactor, Charles Carey
Dissertations, Master's Theses and Master's Reports
NASA and other agencies are working to return to the moon, with the Artemis Program [1]. As a part of this new effort, an emphasis is being placed on having a sustained presence, building lunar bases and other permanent structures. The development of such infrastructure will require the development of civil engineering structures, and site preparation becomes a necessity. The Planetary Surface Technology Development Laboratory is developing a low mass lunar compactor as part of an autonomous site preparation vehicle in partnership with Colorado School of Mines, funded by NASA’s 2021 Lunar Surface Technology Research grant. The low mass lunar …
Development Of Practical Assessment Techniques For Sinkhole Potential In Florida Based On Sinkhole Vulnerability Indices,
2023
University of North Florida
Development Of Practical Assessment Techniques For Sinkhole Potential In Florida Based On Sinkhole Vulnerability Indices, Sylvia Pesha
UNF Graduate Theses and Dissertations
Sinkholes are natural geohazards prevalent in Florida's distinctive karst geology, posing risks to public safety, infrastructure, and groundwater integrity. Considering the increasing frequency of sinkhole occurrences in Florida due to land development in vulnerable soils, understanding the potential for sinkhole occurrence can aid in the identification of high-risk locations and inform effective mitigation strategies. Researchers have developed three point-based indices to be used when assessing the vulnerability a project site has to sinkhole formation based on the encountered subsurface conditions. Engineers have historically used an index based on the subsurface layer thicknesses, called the Raveling Index (RI). In recent years, …
New Online Approach For Real-Time Precise Point Positioning Gnss Processing,
2023
Civil Engineering department, Mansoura University, The Higher Institute of Engineering and Technology, 33512, Kafr Elsheikh, Egypt
New Online Approach For Real-Time Precise Point Positioning Gnss Processing, Maha Fekry Elrewiny, Fawzi H. Zarzoura, Mahmoud El-Mewafi
Mansoura Engineering Journal
Real-time precise point positioning (PPP) is a promising technique for accurate position services. The merging of many systems is intended to increase real-time PPP performance. With a rising number of available satellites and progressively increased quality of real-time accurate products of satellite clocks and orbits, Platforms such as CSRS-PPP, AUSPOS, Magic-GNSS, Trimble, and PPP-MANS are reshaping the landscape of embedded solutions in a variety of sectors. the performance of real-time PPP must be tested on a regular basis. This article examines the benefits and drawbacks of real-time PPP, emphasizing its potential for high accuracy, fast decision-making, and easy interaction with …
Design Aspects Of Deep Water Distribution Shafts,
2023
CUNY New York City College of Technology
Design Aspects Of Deep Water Distribution Shafts, Navid Allahverdi, V. Nasr
Publications and Research
This paper covers aspects of planning and designing of deep shafts with reference to two water distribution shafts under construction in New York City. The new shafts will be sunk into soil and rock to a depth to connect to existing Queens-Brooklyn tunnel section of City Tunnel No. 3 (CT3). The inside diameter of the upper parts of both shafts is 14.9 meter. Artificial ground freezing is specified as preferred method of excavation support for the entire stretch in soil. Excavation in competent rock will be performed using drill and blast technique preceded by a pre-excavation grouting program. Membrane waterproofing …
Numerical Study Of Sediment Suspension Affected By Rigid Cylinders Under Unidirectional And Combined Wave-Current Flows,
2023
Old Dominion University
Numerical Study Of Sediment Suspension Affected By Rigid Cylinders Under Unidirectional And Combined Wave-Current Flows, Sha Lou, Xiaolan Chen, Shengyu Zhou, Gangfeng Ma, Shuguang Liu, Larisa Dorzhievna Radnaeva, Elena Nikitina, Irina Viktorovna Fedorova
Civil & Environmental Engineering Faculty Publications
Sediment transport modeling for flows with cylinders is very challenging owing to the complicated flow–cylinder–sediment interactions, especially under the combined wave-current flows. In this paper, an improved formulation for incipient sediment suspension considering the effect of cylinder density (i.e., solid volume fraction) is employed to simulate the bottom sediment flux in the flow with cylinders. The proposed model is calibrated and validated using laboratory measurements under unidirectional and combined wave-current flows in previous studies. It is proved that the effects of cylinders on sediment suspension can be accounted for through a modified critical Shields number, and the proposed model is …
Editorial: Rock Physics Modeling And Well-Log Practice For Unconventional Reservoirs,
2023
Edith Cowan University
Editorial: Rock Physics Modeling And Well-Log Practice For Unconventional Reservoirs, Qiaomu Qi, Lidong Dai, Maxim Lebedev, Tobias Müller, Junfang Zhang
Research outputs 2022 to 2026
Unconventional resources with commercial interest in the world mainly include heavy oils, shales, coalbed methane and tight gas sands. The production and development of these resources have changed the supply pattern of global energy. Quantitative interpretation of geophysical data in the exploration, well logging and engineering development of the unconventional resources requires a comprehensive understanding of the physical properties of rocks and their relationships. The research of rock physics provides an interdisciplinary treatment of physical properties, whether it is highly related to geological, geophysical and geomechanical methodologies. The development of new rock physics methods is essential when integrating core, well-log, …
A New Volumetric Strain-Based Method For Determining The Crack Initiation Threshold Of Rocks Under Compression,
2023
Edith Cowan University
A New Volumetric Strain-Based Method For Determining The Crack Initiation Threshold Of Rocks Under Compression, Hao Li, Ruizhi Zhong, Leo Pel, David Smeulders, Zhenjiang You
Research outputs 2022 to 2026
The crack initiation stress threshold ( ci) is an essential parameter in the brittle failure process of rocks. In this paper, a volumetric strain response method (VSRM) is proposed to determine the σci based on two new concepts, i.e., the dilatancy resistance state index ( ci) and the maximum value of the dilatancy resistance state index difference (| ci|), which represent the state of dilatancy resistance of the rock and the shear sliding resistance capacity of the crack-like pores during the compressive period, respectively. The deviatoric stress corresponding to the maximum | ci| is taken as the ci . We …
