Geotechnical Engineering Commons^™

Experimental Study On Rock Joint Permeability Evolution During Plugging Process By Microbially Induced Calcite Precipitation, Wei-Min Xiao, Xin Lin, Jian-Min Zhong, Shuang Li, Zhan-Yuan Zhu

Rock and Soil Mechanics

Microbially induced calcite precipitation (MICP) has been widely applied for soil reinforcement, but its applications in rock mass permeability reduction have been rarely reported. To explore the plugging mechanism of rock joints using MICP, artificial rock joint specimens made of transparent resin were prepared, and laboratory MICP plugging experiments under six various conditions considering MICP reaction influence factors were performed. Through the plugging experiments, evolution laws of rock joint transmissivity and hydraulic aperture, accompanied with corresponding CaCO3 distribution images, during plugging processes were obtained. The experimental results showed that the hydraulic aperture of rock joint approximately decreases linearly with grouting …

Mechanical Properties Of Sand 3d Printed Rock-Like Samples Based On Different Post-Processing Methods, Wei Tian, Xiao-Hui Wang, Wei Yun, Xu Cheng

Rock and Soil Mechanics

3D printing, a rapid prototyping technology, has great potential for applications in laboratory rock tests, but the low strength and stiffness of 3D printed samples have been one of the key problems that need to be addressed. In order to find a way to enhance the strength and stiffness of 3D printed rock-like samples, GS19 sand and furan resin were selected as printing materials, and sand 3D printed rock-like samples were used as research objects. Based on this, the samples were post-processed using three different methods: vacuum infiltration, low-temperature treatment, and combination of infiltration and low-temperature. Uniaxial compression tests were …

Shear Fracture Mechanical Properties And Acoustic Emission Characteristics Of Discontinuous Jointed Granite, Gang Wang, Lei-Bo Song, Xi-Qi Liu, Chun-Yan Bao, Man-Qing Lin, Guang-Jian Liu

Rock and Soil Mechanics

No abstract provided.

Establishment Of Constitutive Relation Of Shear Deformation For Irregular Joints In Sandstone, Tan Cheng, Bao-Hua Guo, Jie-Hao Sun, Shi-Xuan Tian, Chong-Xuan Sun, Yan Chen

Rock and Soil Mechanics

The shear deformation of rock joints is significant for the safety and stability of rock engineering. In order to study the constitutive relation of shear deformation in jointed rock mass under a normal stress, the direct shear tests under different normal stresses were carried out on the sandstone specimens with irregular joints using the RDS-200 rock direct shear test system. Based on the shear stress-deformation curve of the jointed rock, it can be divided into four stages including pre-peak compaction stage, linear stage, yield stage and post-peak softening stage. The post-peak softening stage can be further divided into three types …

Quantitative Identification Of Failure Behaviors Of 3d Printed Rock-Like Specimen Containing A Single Hole And Double Cracks, Xiang-Hua Liu, Ke Zhang, Na Li, Fei-Fei Qi, Jin-Ming Ye

Rock and Soil Mechanics

In order to investigate the mechanical properties and failure mechanisms of the rock containing a single hole and double cracks, we used the 3D sand printing technique to prepare the rock-like specimens. Digital image correlation (DIC) method was employed to non-contactly monitor the deformation field of the specimens during the compression process. By calculating the convariance matrix of the horizontal, vertical and shear strains, we introduced the effective variance of the strain field to quantify and identify the failure behaviors of the specimens. The test results indicate that the mechanical properties of the standard 3D sand printed specimens are similar …

Fracturing Mechanism Of Rock-Like Specimens With Different Joint Densities Based On Dic Technology, Fei-Fei Qi, Ke Zhang, Jian-Bin Xie

Rock and Soil Mechanics

In order to study the influence of joint density on the strength characteristics and failure modes of rock mass, the rock-like specimens with different joint densities were prepared by using 3D sand printing, with the quartz sand and furan resin being employed as the printing materials. The uniaxial compression test was performed on the 3D sand printed specimens, and the digital image correlation (DIC) method was used as a non-contact technique to monitor the full-field deformation. The crack initiation, propagation and coalescence behaviors were quantitatively analyzed from the micromechanics point of view. The results show that the shape of stress-strain …

Deformation And Fracturing Characteristics Of Fracture Network Model And Influence Of Filling Based On 3d Printing And Dic Technologies, Ke Zhang, Fei-Fei Qi, Yu-Long Chen

Rock and Soil Mechanics

Due to the complexity of fracture distribution in engineering rock mass, the physical modeling of fracture network is one of the key problems in rock mechanics experiments. In this study, a 3D printing method of fracture network model based on water-soluble materials with polyactic acid materials as supporting base is proposed. Based on the water solubility of printing material, a method for preparing rock-like model specimens containing fracture network is established. Through digital image correlation (DIC) method, the deformation and fracturing characteristics of rock-like model specimens during loading process are quantitatively studied, and the influence law of filling material is …

Development And Application Of Contact Algorithms For Rock Shear Fracture Surface, Qiu-Feng Ma, Yue-Ping Qin, Tian-Bai Zhou, Xiao-Bin Yang

Rock and Soil Mechanics

To overcome the inefficiency of existing numerical algorithms in calculating the contact slip law of complex fracture surfaces, a new numerical calculation algorithm was proposed by adoption of the idea of boundary element method. In this algorithm, all nodes were located at the boundary of rock blocks, and the interaction force between rock blocks and the displacement of rock blocks were calculated by using the explicit differential method. The algorithm was validated by two simulation experiments, i.e. “ball sliding on paraboloid” and “dumbbell on the inclined plane”. The results show the algorithm can accurately describe the contact between objects and …

Slides: Impacts Of Oil Shale On Carbon Emissions, Jeremy Boak

The Promise and Peril of Oil Shale Development (February 5)

Presenter: Dr. Jeremy Boak, Center for Oil Shale Technology & Research, Colorado School of Mines

43 slides

Tensile Strength And Failure Criterion Of Analog Lithophysal Rock, James A. Nott

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project determines the tensile strength of lithophysal analog rock and presents failure criteria that can be used by geotechnical engineers to evaluate underground structures in rock. The physical and mechanical properties that are related to the failure criterion, such as porosity, compressive strength and modulus of elasticity, are also discussed. Experimental tensile tests were made using direct uniaxial and indirect Brazilian tests. Three 4-inch specimens were fabricated and tested in direct uniaxial tensile tests using Hydro-Stone TB. The results showed that the elastic tensile modulus of elasticity was within two percent of existing data for the compressive modulus of …

Sub-Surface Corrosion Research On Rock Bolt System, Perforated Ss Sheets And Steel Sets For The Yucca Mountain Repository, Dhanesh Chandra, Jaak J.K. Daemen, Jaime Gonzalez, Raymond Keeler, Amy J. Smiecinski

Publications (YM)

The objective of the proposed investigation is to conduct corrosion research and predict the durability of rock-bolts and other underground metallic roof supports. In critical areas, it is possible to use highly corrosion resistant steels for rock bolts at Yucca Mountain (YM) repository, as the steel rock bolts, as well as other materials such as Bernold type shields for tunnels at YM site [1-4]. In addition, there is propensity for stress corrosion cracking as well as hydrogen induced cracking in rock bolts likely to occur in YM repository emplacement under drift conditions. As corrosion of these materials for underground support …