This page has only limited features, please log in for full access.
Based on the excavation of Yuelongmen tunnel on ChengLan Railway in China, this paper will probe into the forced ventilation effect of harmful gas generated by drilling and blasting construction, simulate the diffusion process of harmful gas generated during blasting operation on the tunnel face by establishing the finite element model of gas turbulent flow and concentration diffusion in the tunnel, and study the spatial-temporal evolution law of CO concentration field under different air pipe layout locations and tunnel excavation methods. The results show that, compared with corner layout, haunch layout, and central layout, the ventilation effect is the best when the air pipes are arranged near the wall at the tunnel vault, and the CO concentration can be reduced to the concentration limit after 588 s of ventilation; compared with the full-face tunneling method and the lower pilot heading method, the benching tunneling method can effectively reduce the retention time of CO near the tunnel face, and the CO concentration on the tunnel face can be reduced to the standard limit after 326 s of ventilation near the wall of tunnel vault.
Qingsong Pu; Yi Luo; Junhong Huang; Yingwei Zhu; Shaohua Hu; Chenhao Pei; Guang Zhang; Xinping Li. Simulation Study on the Effect of Forced Ventilation in Tunnel under Single-Head Drilling and Blasting. Shock and Vibration 2020, 2020, 1 -12.
AMA StyleQingsong Pu, Yi Luo, Junhong Huang, Yingwei Zhu, Shaohua Hu, Chenhao Pei, Guang Zhang, Xinping Li. Simulation Study on the Effect of Forced Ventilation in Tunnel under Single-Head Drilling and Blasting. Shock and Vibration. 2020; 2020 ():1-12.
Chicago/Turabian StyleQingsong Pu; Yi Luo; Junhong Huang; Yingwei Zhu; Shaohua Hu; Chenhao Pei; Guang Zhang; Xinping Li. 2020. "Simulation Study on the Effect of Forced Ventilation in Tunnel under Single-Head Drilling and Blasting." Shock and Vibration 2020, no. : 1-12.
This study is based on the tunnel-face slope engineering of Dongfeng tunnel in Shanxi section of China’s Shuozhou-Huanghua Railway. The sandstone specimens in the perennial freeze-thaw zone of the slope were collected to carry out freeze-thaw cycle static physical mechanics test and split Hopkinson pressure bar (SHPB) dynamic mechanical test. Thus, the damage process of sandstone under freeze-thaw cycle and impact load is studied. Also, the dynamic compressive strength and dynamic elastic modulus of sandstone are analysed under different loading strain rates and freeze-thaw cycle based on LS-DYNA, a dynamic finite element program. The results showed that the dynamic compressive strength of sandstone subjected to multiple freeze-thaw cycles under 0.04 MPa air pressure has a greater damage ratio than that under 0.055 MPa and 0.07 MPa air pressure, which was more likely to cause damage to slope sandstone than in actual engineering; the dynamic compressive strength and elastic modulus of sandstone decrease greatly within a certain range of freeze-thaw cycles and loading strain rate, leading to significant deterioration. When the freeze-thaw cycle exceeded 200 times and the strain rate was greater than 200 s−1, the physical and mechanical properties of sandstone gradually tended to be stable.
Qingsong Pu; Junhong Huang; Fuling Zeng; Yi Luo; Xinping Li; Jixue Zhou; Shilong Zheng. Study on Long-Term Dynamic Mechanical Properties and Degradation Law of Sandstone under Freeze-Thaw Cycle. Shock and Vibration 2020, 2020, 1 -10.
AMA StyleQingsong Pu, Junhong Huang, Fuling Zeng, Yi Luo, Xinping Li, Jixue Zhou, Shilong Zheng. Study on Long-Term Dynamic Mechanical Properties and Degradation Law of Sandstone under Freeze-Thaw Cycle. Shock and Vibration. 2020; 2020 ():1-10.
Chicago/Turabian StyleQingsong Pu; Junhong Huang; Fuling Zeng; Yi Luo; Xinping Li; Jixue Zhou; Shilong Zheng. 2020. "Study on Long-Term Dynamic Mechanical Properties and Degradation Law of Sandstone under Freeze-Thaw Cycle." Shock and Vibration 2020, no. : 1-10.
The research on the stability of rock slopes under the multi-field coupling has important theoretical and practical significance for the analysis and prevention of freeze–thaw disasters of engineering in cold regions. In this paper, COMSOL Multiphysics numerical simulation software and numerical simulation methods are adopted. Based on the coupling theory of rock stress field, seepage field, temperature field, and chemical field, and field test data, the stability of rock slope under the multi-field coupling is studied under the research background of the highway slope of Jinghe to Yining County of G577 line. Based on the study of multi-field coupling theory, a numerical calculation model is established, the rationality of the numerical calculation model is verified, and the maximum frozen thickness of the slope is determined. On this basis, the change rules of the relevant parameters such as stress, temperature, deformation and damage of the highway slope in the engineering area are studied. The slope stability analysis is performed based on the YAI slope stability evaluation method. The stability of the slope is analyzed from the freezing, thawing and freeze–thaw process states of the shallow layer of the slope. It provides a theoretical basis for engineering construction in cold region.
Dengxing Qu; Yi Luo; Xinping Li; Gang Wang; Guang Zhang; Kun Xu. Study on the Stability of Rock Slope Under the Coupling of Stress Field, Seepage Field, Temperature Field and Chemical Field. Arabian Journal for Science and Engineering 2020, 45, 8315 -8329.
AMA StyleDengxing Qu, Yi Luo, Xinping Li, Gang Wang, Guang Zhang, Kun Xu. Study on the Stability of Rock Slope Under the Coupling of Stress Field, Seepage Field, Temperature Field and Chemical Field. Arabian Journal for Science and Engineering. 2020; 45 (10):8315-8329.
Chicago/Turabian StyleDengxing Qu; Yi Luo; Xinping Li; Gang Wang; Guang Zhang; Kun Xu. 2020. "Study on the Stability of Rock Slope Under the Coupling of Stress Field, Seepage Field, Temperature Field and Chemical Field." Arabian Journal for Science and Engineering 45, no. 10: 8315-8329.
Nepal is a sensitive earthquake zone. On April 25, 2015, there was an Earthquake of 7.8 Mw. After that, more than 30 aftershocks of above 5 Mw occurred. One of the aftershocks was of 7.3 Mw which occurred on May 12. In this paper, the damages in the tunnel of the Melamchi water supply project due to this earthquake were assessed. Cracks were observed on the inside surface, wall, and crown of the tunnel. Distribution and characteristics of these seismic damages were investigated and summarised to assess potential influencing factors. The damages are categorized into the following patterns: lining cracks and spalling. Lining cracks are further divided into longitudinal cracks, transverse cracks, ring cracks, and inclined cracks. Influencing factors are discussed with respect to Earthquake parameters mainly being magnitude, depth and distance to epicenter. This paper presents the pattern of seismic damages occurred for different overburden depths and different rock types. Here, the analysis is done by observation and categorization of damages for different aspects of considered factors and there are some unusual results in damages for varying overburden depths. There were few unusual results as in the damage distribution for overburden depth and also for different rock types. The reason may be the occurrence of many considerable aftershocks and epicenter being very near, so the damages may have been accumulated after each shock. Also the distribution of rock types have influenced the damages. So one influencing factors may have its effects on the results while considering the other factor.
Rajyaswori Shrestha; Xinping Li; Luo Yi; Abhay Kumar Mandal. Seismic Damage and Possible Influencing Factors of the Damages in the Melamchi Tunnel in Nepal Due to Gorkha Earthquake 2015. Geotechnical and Geological Engineering 2020, 38, 5295 -5308.
AMA StyleRajyaswori Shrestha, Xinping Li, Luo Yi, Abhay Kumar Mandal. Seismic Damage and Possible Influencing Factors of the Damages in the Melamchi Tunnel in Nepal Due to Gorkha Earthquake 2015. Geotechnical and Geological Engineering. 2020; 38 (5):5295-5308.
Chicago/Turabian StyleRajyaswori Shrestha; Xinping Li; Luo Yi; Abhay Kumar Mandal. 2020. "Seismic Damage and Possible Influencing Factors of the Damages in the Melamchi Tunnel in Nepal Due to Gorkha Earthquake 2015." Geotechnical and Geological Engineering 38, no. 5: 5295-5308.
The laboratory experiment of the spilt Hopkinson pressure bar is carried out, and the cyclic load simulation is realized by a new method based on two-dimensional particle flow code (PFC2D) program. The dynamic damage and failure process of sandstone under cyclic impact load are further observed and analyzed from the view of mesoscopic scale. The results are as follows: (1) The numerical calculation method based on particle flow discrete element can effectively reproduce the Hopkinson bar impact compression experiment. (2) Under the cyclic impact load, the number of cracks in the specimens increases continuously, showing the effect on mechanical properties such as strength deterioration, elastic modulus reduction and peak strain increase. The number of cracks increases sharply at the moment of failure, and the peak strain and elastic modulus change significantly. (3) Along with the increase in cycle numbers of impact load, the failure modes of sandstone specimens develop from the mode of local meso-cracks at the end of the specimen and a small amount of rock debris to axial splitting failure mode dominated by main meso-cracks and extended from the end to the middle of the specimen. Compared with impact test with high strain rate, the failure evolution trend of sandstone specimens with axial preferential development of main meso-cracks is more significant. (4) The dynamic deterioration characteristics and evolution laws of meso-cracks in rock under cyclic impact load, such as nucleation, propagation, connectivity and interaction, are studied using PFC2D program, making up the shortcomings of laboratory experiment.
Gang Wang; Yi Luo; Xinping Li; Tingting Liu; Mingnan Xu; Dengxing Qu. Study on Dynamic Mechanical Properties and Meso-Deterioration Mechanism of Sandstone Under Cyclic Impact Load. Arabian Journal for Science and Engineering 2019, 45, 3863 -3875.
AMA StyleGang Wang, Yi Luo, Xinping Li, Tingting Liu, Mingnan Xu, Dengxing Qu. Study on Dynamic Mechanical Properties and Meso-Deterioration Mechanism of Sandstone Under Cyclic Impact Load. Arabian Journal for Science and Engineering. 2019; 45 (5):3863-3875.
Chicago/Turabian StyleGang Wang; Yi Luo; Xinping Li; Tingting Liu; Mingnan Xu; Dengxing Qu. 2019. "Study on Dynamic Mechanical Properties and Meso-Deterioration Mechanism of Sandstone Under Cyclic Impact Load." Arabian Journal for Science and Engineering 45, no. 5: 3863-3875.
Based on the laboratory experiments of spilt Hopkinson pressure bar (SHPB), a numerical model of PFC2D (2 Dimensional Particle Flow Code) is established. The characteristics of crack number and propagation path closely related to material strain rate effect and failure mode are further analysed from a mesoscopic point of view. The dynamic damage and failure process of joint specimens under impact load are studied. The results show that: (1) Prefabricated joints weaken the integrity of rock and reduce the compressive strength of specimen, (2) According to the law of crack development, the failure stage of specimen can be divided into elastic deformation stage, crack initiation stage, rapid crack propagation stage and slow cracks propagation stage, (3) Prefabricated joints affect the failure characteristics of specimens. The crack propagation and failure modes of specimens have ‘rate effect’. At lower strain rates, the cracks of prefabricated joint specimens with the dip angle of 30° are wing cracks and coplanar cracks. With the increase of loading strain rate, the development of anti-wing cracks becomes more and more obvious. The crack initiation angle of wing cracks ranges from 55° to 80°, and the crack initiation angle of anti-wing cracks ranges from 115° to 130°.
Gang Wang; Yi Luo; Xinping Li; Tingting Liu; Ruiqiu Ma; Dengxing Qu. Study on dynamic mechanical properties and meso-damage mechanism of jointed rock under impact load. European Journal of Environmental and Civil Engineering 2019, 1 -17.
AMA StyleGang Wang, Yi Luo, Xinping Li, Tingting Liu, Ruiqiu Ma, Dengxing Qu. Study on dynamic mechanical properties and meso-damage mechanism of jointed rock under impact load. European Journal of Environmental and Civil Engineering. 2019; ():1-17.
Chicago/Turabian StyleGang Wang; Yi Luo; Xinping Li; Tingting Liu; Ruiqiu Ma; Dengxing Qu. 2019. "Study on dynamic mechanical properties and meso-damage mechanism of jointed rock under impact load." European Journal of Environmental and Civil Engineering , no. : 1-17.
To make sure the integrity and stability of surrounding rock structure during blasting excavation of important structural planes in deep underground caverns, two kinds of fine blasting methods, timing sequence control fracture blasting network and notch blast hole, are innovatively combined and the formation of cracks between smooth blasting holes with different delay initiation and different shapes of primary blast holes (PBHs) are compared and analyzed. The results show that when the delay initiation time between the successive explosion holes is greater than or equal to the transverse wave of the PBH propagates to the target blast hole (TBH), the concentrated stress along the connection direction of the hole on the wall of the TBH is larger than the other directions of the hole wall. After the TBH is detonated, cracks will preferentially expand along the connection direction of the blast holes. If the PBH is the notch blast hole, more explosive energy will be directed to the wall of the TBH so that the hole wall along the connection direction of the blast holes will be subjected to greater tension stress before the initiation of the TBH. In this way, the interval between successive holes can be increased and the efficiency of blasting excavation of rock mass can be improved accordingly.
Xinping Li; Junlin Lv; Junhong Huang; Yi Luo; Tingting Liu. Numerical Simulation Research of Smooth Wall Blasting Using the Timing Sequence Control Method under Different Primary Blast Hole Shapes. Shock and Vibration 2019, 2019, 1 -16.
AMA StyleXinping Li, Junlin Lv, Junhong Huang, Yi Luo, Tingting Liu. Numerical Simulation Research of Smooth Wall Blasting Using the Timing Sequence Control Method under Different Primary Blast Hole Shapes. Shock and Vibration. 2019; 2019 ():1-16.
Chicago/Turabian StyleXinping Li; Junlin Lv; Junhong Huang; Yi Luo; Tingting Liu. 2019. "Numerical Simulation Research of Smooth Wall Blasting Using the Timing Sequence Control Method under Different Primary Blast Hole Shapes." Shock and Vibration 2019, no. : 1-16.
In the rock engineering of cold region eroded by chemical solution such as groundwater and acid rain, the pore development law, damage degree and failure characteristics of rock are closely related to the coupling effect of chemical solution and freeze-thaw. The freeze-thaw cycles of sandstones in different chemical solutions are experimented. The pore variation law and damage evolution mechanism of sandstones immersed in different chemical solutions are studied by means of nuclear magnetic resonance (NMR). The sandstone samples are placed in acidic solution, alkaline solution, neutral salt solution and aqueous solution for freeze-thaw cycling test. The composition, porosity change and T2 curve change of the samples are analyzed. The results show that the porosity of sandstone samples increases with the increase of the number of freeze-thaw cycles under the coupling of chemical solutions and freeze-thaw cycle. After 40 freeze-thaw cycles, the change rate of porosity is from large to small: neutral NaCl solution, H2SO4 solution, NaOH solution, aqueous solution. The pore sizes of all the samples affected by the coupling of chemical solution and freeze-thaw are mainly concentrated in two sizes, and the larger pore size is dominant. In neutral NaCl solution, chemical corrosion and freeze-thaw effect promote each other and play a superposition effect. In H2SO4 and NaOH solution, the superposition effect of chemical corrosion and freeze-thaw effect is inhibited to a certain extent. At the same time, according to the variation law of sample porosity in different chemical solutions, the quantitative expression of damage variable of the sample is obtained, and the damage evolution model of sandstone is derived.
Xinping Li; Dengxing Qu; Yi Luo; Ruiqiu Ma; Kun Xu; Gang Wang. Damage evolution model of sandstone under coupled chemical solution and freeze-thaw process. Cold Regions Science and Technology 2019, 162, 88 -95.
AMA StyleXinping Li, Dengxing Qu, Yi Luo, Ruiqiu Ma, Kun Xu, Gang Wang. Damage evolution model of sandstone under coupled chemical solution and freeze-thaw process. Cold Regions Science and Technology. 2019; 162 ():88-95.
Chicago/Turabian StyleXinping Li; Dengxing Qu; Yi Luo; Ruiqiu Ma; Kun Xu; Gang Wang. 2019. "Damage evolution model of sandstone under coupled chemical solution and freeze-thaw process." Cold Regions Science and Technology 162, no. : 88-95.
The ground vibration wave induced by the viaduct section of the heavy freight wagons is transformed into the ground vibration problem under the condition of point source excitation after it is transmitted to soil through pier. When the speed and axle load of wagon become larger and larger, the impact on the surrounding buildings will also increase. In this paper, the ground vibration around Shenshan Village in section of Shuo-Huang railway line is monitored and numerical analyzed; the 3D numerical model of the Bridge-Pier-Field-House system is established. The relationship between peak vibration velocity (PPV) and the distance to the pier caused by heavy freight wagons at different speeds and different type of wagons is analyzed. The power function relationship between the two when measuring line perpendicular to the centerline of railway is verified. Based on the modified Sodev’s equation, the relationship between PPV of ground points and wagon speed, axle load, and soil properties is proposed, and the value of every parameter in the formula is discussed in detail. The concept of energy index is put forward for the first time in the formula, and the relationship between energy index and wagon speed and wagon weight is analyzed by regression analysis. The accuracy of the calculation model and prediction formula is verified by comparing field test results; an analytical method is proposed to predict the ground vibration induced by viaduct.
Jingjing Hu; Yi Luo; Jiayun Xu. Experimental and Numerical Analysis and Prediction of Ground Vibrations Due to Heavy Haul Railway Viaduct. Mathematical Problems in Engineering 2019, 2019, 1 -15.
AMA StyleJingjing Hu, Yi Luo, Jiayun Xu. Experimental and Numerical Analysis and Prediction of Ground Vibrations Due to Heavy Haul Railway Viaduct. Mathematical Problems in Engineering. 2019; 2019 ():1-15.
Chicago/Turabian StyleJingjing Hu; Yi Luo; Jiayun Xu. 2019. "Experimental and Numerical Analysis and Prediction of Ground Vibrations Due to Heavy Haul Railway Viaduct." Mathematical Problems in Engineering 2019, no. : 1-15.
Due to high water pressure in the concrete reinforced hydraulic tunnels, surrounding rocks are confronted with nonlinear seepage problem in the pumped storage power station. In this study, to conduct nonlinear seepage numerical simulation, a nonlinear seepage numerical model combining the Forchheimer nonlinear flow theory, the discrete variational inequality formulation of Signorini’s type and an adaptive penalized Heaviside function is established. This numerical seepage model is employed to the seepage analysis of the hydraulic tunnel surrounding rocks in the Yangjiang pumped-storage power station, which is the highest water pressure tunnel under construction in China. Moreover, the permeability of the surrounding rocks under high water pressure is determined by high pressure packer test and its approximate analytical model. It is shown that the flow in the surrounding rocks is particularly prone to become nonlinear as a result of the high flow velocities and hydraulic gradients in the nearby of the seepage-control measures and the high permeability fault. The nonlinear flow theory generates smaller flow rate than the Darcy flow theory. With the increase of nonlinear flow, this observation would become more remarkable.
Shaohua Hu; Xinlong Zhou; Yi Luo; Guang Zhang. Numerical Simulation Three-Dimensional Nonlinear Seepage in a Pumped-Storage Power Station: Case Study. Energies 2019, 12, 180 .
AMA StyleShaohua Hu, Xinlong Zhou, Yi Luo, Guang Zhang. Numerical Simulation Three-Dimensional Nonlinear Seepage in a Pumped-Storage Power Station: Case Study. Energies. 2019; 12 (1):180.
Chicago/Turabian StyleShaohua Hu; Xinlong Zhou; Yi Luo; Guang Zhang. 2019. "Numerical Simulation Three-Dimensional Nonlinear Seepage in a Pumped-Storage Power Station: Case Study." Energies 12, no. 1: 180.
In view of the influence of blasting excavation in the deep burial underground powerhouse on the dynamic disturbance and blasting vibration of side wall and surrounding rock, the blasting vibration test method is often used for on-site monitoring and control. Taking the blasting excavation of the high side wall of an underground powerhouse of a hydropower station as the engineering background, a long-term blasting vibration test is carried out on the site. The measuring points are arranged along the elevation direction and horizontal direction of the high side wall of the powerhouse. Through analyzing and comparing the blasting vibration velocity values extracted from a large number of on-site measured data in the elevation direction, an interesting phenomenon is found. The measured vibration velocity of the rock anchor beam in the area far away from the blasting is greater than that in the area near the blasting, and the vibration velocity after the casting of the rock anchor beam is greater than that before the casting. In order to avoid the randomness and contingency of the measured data, based on the blasting parameters, loading quantity, and rock mechanical characteristics used in the field, the elevation effect of the numerical model of the underground powerhouse is established by using the dynamic finite element software. By comparing the numerical simulation and the on-site monitoring of the elevation direction vibration velocity at the same location, it is found that the two have the same law, which verifies the reliability of the numerical calculation model. By changing the elevation and horizontal distances to select the measuring points in the numerical model, the propagation curve of the blasting vibration of the high side wall of the underground powerhouse in the elevation direction is obtained and the wave propagation phenomenon and the local elevation amplification effect of blasting vibration velocity in the side wall of the powerhouse are found. By means of changing the morphology characteristics of the rock anchor beam, a numerical calculation model of the rock anchor beam before casting is established, and the blasting vibration velocity in the elevation direction of the same measuring point as the original model is extracted. The analysis and comparison results show that the “whiplash effects” caused by the reflection superposition of the convex morphology characteristics of the rock anchor beam on the blast wave and the vibration response of the rock mass at the step part is the main factor for the elevation effect. The fluctuation phenomenon of the vibration velocity in the elevation direction is caused by the natural frequency and the main vibration mode of the high side walls, and the reflection superposition of the convex geomorphology characteristics of the rock anchor beam will aggravate this fluctuation phenomenon. Therefore, in the construction of deep underground powerhouses, attention should be paid to the blasting construction and support design of the rock anchor beam.
Xinping Li; Junlin Lv; Yi Luo; Tingting Liu. Mechanism Study on Elevation Effect of Blast Wave Propagation in High Side Wall of Deep Underground Powerhouse. Shock and Vibration 2018, 2018, 1 -15.
AMA StyleXinping Li, Junlin Lv, Yi Luo, Tingting Liu. Mechanism Study on Elevation Effect of Blast Wave Propagation in High Side Wall of Deep Underground Powerhouse. Shock and Vibration. 2018; 2018 ():1-15.
Chicago/Turabian StyleXinping Li; Junlin Lv; Yi Luo; Tingting Liu. 2018. "Mechanism Study on Elevation Effect of Blast Wave Propagation in High Side Wall of Deep Underground Powerhouse." Shock and Vibration 2018, no. : 1-15.
Studies on ground vibration induced by railway operation usually focused on wagons running on ground or abutments, while vibration from a railway viaduct is often assumed to be much lower. Based on field test in the vicinity of a heavy freight railway viaduct above Shenshan Village, China, the attenuation of ground vibration induced by heavy freight wagons for coal transportation is studied. And evaluation is conducted on an adjacent house to access vibration disturbance to residents near a viaduct. Propagation and attenuation of vibration induced from viaduct are studied by analyzing peak particle velocity and spectra of ground and house vibration in the vicinity of the viaduct. Vibration signals were collected for 34 trains with different train speed and wagon weight. In all monitored situations, vertical vibration is generally larger than horizontal vibration. The relationship between distance to pier and PPV is revealed by a power function modified from Sadovskii formula with high correlation factor. Analysis also indicates a much lower dominant frequency induced by low-speed trains with or without acceleration than normal speed trains. A dramatic amplitude reduction is shown within frequency between 25 Hz and 35 Hz when train speed is reduced. Empty wagons also show smaller amplitude in most frequency bands, with significant difference in 15–25 Hz. Analysis on the house also shows larger vibration in vertical than horizontal, and vibration amplitude in some frequency bands has exceeded relative criteria. Analysis result shows significant ground and house vibration effect form a viaduct, and piers should be considered as vibration sources for ground and houses in future studies.
Jingjing Hu; Yi Luo; Zaitian Ke; Penghui Liu; Jiayun Xu. Experimental study on ground vibration attenuation induced by heavy freight wagons on a railway viaduct. Journal of Low Frequency Noise, Vibration and Active Control 2018, 37, 881 -895.
AMA StyleJingjing Hu, Yi Luo, Zaitian Ke, Penghui Liu, Jiayun Xu. Experimental study on ground vibration attenuation induced by heavy freight wagons on a railway viaduct. Journal of Low Frequency Noise, Vibration and Active Control. 2018; 37 (4):881-895.
Chicago/Turabian StyleJingjing Hu; Yi Luo; Zaitian Ke; Penghui Liu; Jiayun Xu. 2018. "Experimental study on ground vibration attenuation induced by heavy freight wagons on a railway viaduct." Journal of Low Frequency Noise, Vibration and Active Control 37, no. 4: 881-895.
In Southwest China, most regions are mountainous, where traditional drill-and-blast method is adopted to excavate relatively harder rocks. However, blasting would cause vibration to adjacent structures and might result in damage or even failure. This paper considers a case where subway tunnel is overlying an existing railway tunnel, while the excavation requires blasting method. Vibration and stress distribution are calculated via Dynamic Finite Element Method (DFEM) for both full-face excavation and CD method. Result shows that vibration induced by CD method is only 28% of that caused by full-face blasting with same distance. Peak vibration is located on the lining facing the blasting source, while peak tensile stress is on the other side of the contour due to the reflection of stress wave on strata boundary. And peak value of tensile stress induced by full-face blasting is capable of causing lining failure; thus full-face blasting is not suggested within 40 m beyond the underlying tunnel axis. However, CD method has shown much advantage, since blasting within 25 m is also considered safe to the underlying tunnel. But when the blasting source is as near as 12 m within the underlying tunnel, the CD method is no longer safe.
Jixue Zhou; Yi Luo; Xinping Li; Yunhua Guo; Tingting Liu. Numerical Evaluation on Dynamic Response of Existing Underlying Tunnel Induced by Blasting Excavation of a Subway Tunnel. Shock and Vibration 2017, 2017, 1 -10.
AMA StyleJixue Zhou, Yi Luo, Xinping Li, Yunhua Guo, Tingting Liu. Numerical Evaluation on Dynamic Response of Existing Underlying Tunnel Induced by Blasting Excavation of a Subway Tunnel. Shock and Vibration. 2017; 2017 ():1-10.
Chicago/Turabian StyleJixue Zhou; Yi Luo; Xinping Li; Yunhua Guo; Tingting Liu. 2017. "Numerical Evaluation on Dynamic Response of Existing Underlying Tunnel Induced by Blasting Excavation of a Subway Tunnel." Shock and Vibration 2017, no. : 1-10.
Aiming at surrounding rock damage induced by dynamic disturbance from blasting excavation of rock-anchored beam in rock mass at moderate or far distance in underground cavern, numerical model of different linear charging density and crustal stress in underground cavern is established by adopting dynamic finite element software based on borehole layout, charging, and rock parameter of the actual situation of a certain hydropower station. Through comparison in vibration velocity, contour surface of rock mass excavation, and the crushing extent of excavated rock mass between calculation result and field monitoring, optimum linear charging density of blast hole is determined. Studies are also conducted on rock mass vibration in moderate or far distance to blasting source, the damage of surrounding rock in near-field to blasting source, and crushing degree of excavated rock mass under various in situ stress conditions. Results indicate that, within certain range of in situ stress, the blasting vibration is independent of in situ stress, while when in situ stress is increasing above certain value, the blasting vibration velocity will be increasing and the damage of surrounding rock and the crushing degree of excavated rock mass will be decreasing.
Xinping Li; Junhong Huang; Yi Luo; Qian Dong; Youhua Li; Yong Wan; Tingting Liu. Numerical Simulation of Blast Vibration and Crack Forming Effect of Rock-Anchored Beam Excavation in Deep Underground Caverns. Shock and Vibration 2017, 2017, 1 -13.
AMA StyleXinping Li, Junhong Huang, Yi Luo, Qian Dong, Youhua Li, Yong Wan, Tingting Liu. Numerical Simulation of Blast Vibration and Crack Forming Effect of Rock-Anchored Beam Excavation in Deep Underground Caverns. Shock and Vibration. 2017; 2017 ():1-13.
Chicago/Turabian StyleXinping Li; Junhong Huang; Yi Luo; Qian Dong; Youhua Li; Yong Wan; Tingting Liu. 2017. "Numerical Simulation of Blast Vibration and Crack Forming Effect of Rock-Anchored Beam Excavation in Deep Underground Caverns." Shock and Vibration 2017, no. : 1-13.