bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis on Bearing Wall with Opening Transfer Beams Subjected to Vertical Loads
Authors: Lv Meng Zhou , Liu De Quan , Sun Xiao Yu
Published: July 2014

In shear wall structure with supporting frames, the whole structure' s bearing mechanism is greatly influenced by the opening of shear wall on transfer beam under vertical loads. In this paper, finite element analyses of bearing wall with different type of opening transfer beams subjected to vertical loads were carried out, the influences of opening on transfer beam and shear wall were studied, the stress distribution law and the position of the neutral axises of the transfer beams were presented. The analysis results showed that horizontal stress and the neutral axises of transfer beam change with opening ratio of wall.The points offered in the paper can be referred in shear wall structure with supporting frames design.
The Research of Gantry Crane Girder Damage Problem by Modal Analysis Method
Authors: Nie Xiao Peng , Li Xin Gang , Fan Hong Wei , Ding Ke Qin , Xu Li Bin
Published: July 2014

most crane damage identification of the work has focused on the static analysis, that can't explain whether the crane has a damage or not by this way. So the paper explained the modal signal to analysis this problem , Used 300 tons gantry crane’s beam for background and ANSYS software as a tool was used for numerical simulation. The purpose is to find difference between the damage beam of the crane and health one,because if there was a damage on the beam , the formations and frequency will be changed. This theory of analysis is based on the vibration equation. In order to illustrate it better, the wavelet analysis method as a tool has been used ,in this case the signal was filtered, we can judge the damage location from the three dimensional curve. The basic aim of this paper is to arrive at a better way to judge the damage.Through the above analysis, the results proved the author's idea, identify structural’s damage basically, but it still need further research.
Research on Dynamic Characteristics and Response of Double-Tower Connected Structures
Authors: Liu Qiang
Published: July 2014

The dynamic analysis method and theory of double-tower connected structures is discussed in this paper .Then modal analysis、static and dynamic time-history analysis is researched with the FEM software ANSYS. Through the structure of monomer and comparative study of the structure in different locations, the basic rules of dynamic characteristics and the rules of layout corridor can be achieved. In addition, by symmetric and asymmetric conjoined comparative study, the basic choose rules of structure type can also be achieved.
Free Vibration of Shallow-Spherical Shell
Authors: Hou Xian Qin
Published: July 2014

Shallow spherical shell is one of the structure shapes and is adopted extensively in engineering. Based on the exact solution of free vibration of the shallow-spherical shell, the frequency equations of the shallow spherical shell with clamped edge are derived and calculated numerically. Then the first third-order frequency curve and modal curve and solved. Comparing these with the results of the exact-solution method, the range of of the shallow-spherical shell when calculated by use of practical-solution method can be derived.
An Improved Method of Bridge Finite Element Model Update by Stepwise Regression
Authors: Luo Yong Peng , Huang Fang Lin , Tang Zhong Ping , Xie Jun Li
Published: July 2014

With the increasing of variables and orders of polynomial expansion, the undetermined coefficients of the response surface model have increased dramatically. The insignificant expansion terms should be eliminated because not all of the expansion terms have significant effect on the response. The improved and practical updating method based on response surface model by stepwise regression, which can effectively reduce the undetermined coefficients on the premise of guaranteeing the correcting accuracy, is proposed in this paper. The method is also applied to update the finite element model of a bridge with prestressed reinforced concrete rigid frame-continuous girders based on the in-situ dynamic test results. The results show that the updated finite element model can match the mechanical properties of the bridge well.
Limit Analyisis of Frame Structure Based on the Elastic Modulus Reduction Method
Authors: Duan Qiu Hua , Guo Yan Qing , Zeng Dan Dan , Luo Yue Jing
Published: July 2014

An efficient linear elastic iterative finite element method, namely, the elastic modulus reduction method is introduced to calculate limit load of frame structure. The elastic modulus reduction method defines the element bearing ratio on the basis of the generalized yield criterion and the strain energy equilibrium principle. Because the bending moment is the main factor inducing the frame structure damage, the element bearing ratio only considering the bending moment yield is proposed. Numerical examples demonstrate the applicability and precision of the elastic modulus reduction method for limit analysis of frame structures.
Analysis and Experimental Study on Mechanical Performance of the Extruded Forming Channel Type Embedded Part
Authors: Tan Qian , Jia Chuan Guo , Li Ying Min , Liu Liu
Published: July 2014

A kind of channel type embedded part which has been disposed through extrusion forming new technology needed to extensive apply in engineering. Theoretical analysis and experimental research have been carried out on shear properties of bolt and one-way static pull-out performance of channel. Got the ultimate bearing capacity, deformation and failure mode, compared the results between test and finite element analysis, fit a formula for calculating the bearing capacity of channel. Experimental result shows that embedded parts working performance is good. It has higher strength than work load and the expected ultimate load according to the theoretical calculation. Meantime, specimens has relatively good ductility before failure. The test results have provided the experimental basis for the application of embedded parts in engineering.
Optimization of Steel Lattice Trusses Considering Members Stability
Authors: Zhu Jie Jiang , Zhao Guo Bao , Sun Yu Ming
Published: July 2014

This paper extends the optimization model of space truss finite element method to planar steel lattice truss structures under multiple constraints involved with the strength and the stability of members as well as the mid span deflection based on sequential linear programming (SLP) and affine-scale dual algorithm with the size of members as the optimization variables and the minimum weight as the optimization objective. Algorithm implemented with programming, an example of square pyramid space grid is meant for the verification of the optimization performance that the algorithm and program extends an active control to the stability and the mid span deflection as well simultaneously during optimization. Moreover, stress and deflection constraints were enlarged and reduced, the optimization results indicate that more districted constraints bring about greater ultimate steel consumption, which extends a certification to the effectiveness of the proposal optimization model to deal with all kinds of stress and displacement constraints.
Semi Empirical Equation for Peak Shears Strength of Rectangular Reinforced Concrete Walls with Aspect Ratio Less or Equal to One
Authors: Kezmane Ali , Boukais Said , Hamizi Mohand
Published: July 2014

This paper presents an analytical study on the behavior of reinforced concrete walls with rectangular cross section and aspect ratio less or equal to one. Several experiments on such walls have been selected to be studied. Database from various experiments were collected and nominal shear wall strengths have been calculated using formulas, such as those of the ACI (American), NZS (New Zealand), and Wood and Barda equations. Subsequently, nominal shear wall strengths from the formulas were compared withthe peak shear wall strengths from the database. These formulas vary substantially in functional form and do not account for all variables that affect the response of walls. There is substantial scatter in the predicted values of ultimate shear strength. A new semi empirical equation is developed using data from tests of 126 walls with the objective of improving the prediction of peak strength of walls with the most possible accurate.
Analysis on the Nondestructive Testing Method of Concrete Strength
Authors: Gu Jun Bin
Published: July 2014

Preliminary study the damage of concrete beam by the ultrasonic-rebound method.The contents of the ultrasonic-rebound method are shown below: the concrete rebound value was determined by Rebound method and the ultrasound propagation time in concrete beam was determined by ultrasonic meter to calculate the ultrasonic velocity value in concrete, finally based on the concrete rebound value and the ultrasonic velocity value to confirm the strength of concrete beam.Because of a single rebounding or ultrasonic method is limit in theory and application, and lead to the defect in the application. But the ultrasonic-rebound synthetic method is much better than the above two methods respectively, and it improves the testing precision to apply to the engineering practice.
Analysis to Causes of Concrete Transfer Crossbeam Cracks in the Basement
Authors: Li Lin , Jiang Zhi Jun , Zhang Qin , Peng Sheng Tao , Li Hui
Published: July 2014

In a high-rise building located in Nanchong of Sichuan Province, after the removal of template of the crossbeam of the concrete transfer storey in the basement, there are many vertical and diagonal cracks which can be detected directly by human eyes. According to the structure design data and structural working drawing of this project, multiple detection methods are adopted for the detection on and analysis to the factors caused the cracks. From that, the thesis proposes some feasible handling suggestion as the reference for the similar engineering in future.
Preliminary Ideas of the Metro Station Constructed by Shield Tunneling Method Combined with Prefabricated Method
Authors: Su Hui Feng , Liu Wei Ning , Liu Fu Chun
Published: July 2014

Confronting with the difficulties of the construction metro station in the Northeast of China, a new idea of shield method combined prefabricated method is put forward. In the paper the research status of the underground engineering precast assembly technology was analyzed and classified firstly. The method of single round interval shield combined with open-cut (or covered excavation) prefabricated sections and on the basis of shield tunnel to build single arch station is especially worth studying and promotion. Then the key prefabricate theory needing to deal with such as how to calculating the spring stiffness and so forth of the calculating model. The key technology such as joint formation, waterproof and the other of shield method combined with prefabricated method was discussed.
Research on Layout of Measurement Points in Tunnel Lighting Experiment
Authors: Yang Qiang , Liang Bo , Pan Guo Bing , He Shi Yong , Chen Wei , Dang Xiao Yu , Wu Zhi Wei
Published: July 2014

Based on the measured data of the tunnel lighting, this paper is focusing on the arrangement of measured points in the experiment of tunnel lighting. Through the way of changing the location of measured area and the arrangement of measured points, comparing the simulation from the software DIALUX and the actual measurement in a repetitive region, the best position of measured area and the corresponding layout mode can be found. Analysis shows that, the larger the lamp distance is, the more similar the experiment and simulation results are. Before the experiment, the analysis of the light distribution curve is required, then, the simulation of software can help to find out the best position of lamp interval, measured area and layout mode, in order to ensure the authenticity of the results and to avoid too large or too small lighting evaluation, layout mode must include the maximum measured points and the minimum measured point.
Study of Life Safety on the Fire Accidents in the Subway Station
Authors: Xie Hua , Xu Yan Ying , Zhang Xu , Chen Jian
Published: July 2014

Subway station fire can easily cause many calamities that lead to a large amount of social and public problems, because the smoke spread moves in the same direction as the personnel evacuation. Therefore, life safety issues caused by the subway station fire and relevant investigation should be comprehensively taken into account in the fire safety design in order to minimize the fire accident loss. Here previously reported fire accidents in the subway station are reviewed in detail and some research on the life safety of the subway station fire are presented, which could be helpful for the accident prevention and provide guidance to future study on the safety design in the subway station fire.
Study on Fire Smoke Movement of Urban Traffic Link Tunnel
Authors: Yao Xiao Lin , Zhang Zhi Gang
Published: July 2014

Fire simulation software (FDS) was employed to simulate the fire smoke movement of urban traffic link tunnel (UTLT) under the semi-transverse ventilation. Numerical simulation and theoretical analysis were used to analyze the fire smoke movement in three fire scenarios. The analytical results show that: semi-transverse ventilation can effectively control the spread of fire smoke. When the exhaust air rate is certain, the exhaust port interval of 20 m and 50 m has little effect on function of smoke control. The research results provide references for the design of smoke control measures in UTLT.
Mechanics Analysis of Semi-Rigid Subgrade Pavement Structure
Authors: Su Li Ya
Published: July 2014

The semi-rigid base asphalt pavement structure was choose often used to the highway in our country, but the semi-rigid base asphalt pavement early damage almost has become a common phenomenon.In this paper, the rule and trend of mechanics response about pavement structure (the vertical displacement and tensile stress) were analyzed under the semi-rigid base choose different elasticity modulus and thickness by ANSYS for muti-layer foundation of semi-rigid base pavement design to provide reference.
Study on the Blasting Excavation Method of Urban Shallow Tunnel
Authors: Li Zi Qiang , Li Zheng
Published: July 2014

The construction method requires careful consideration in order to reduce impact of tunnel on the surface of the building in the city. It can have great significance in choosing appropriate blasting excavation method for the poor surrounding rock conditions and complicated ground constructions of shallow buried tunnel. This paper combines the Guanhui urban railway transport projects which the shallow buried tunnel through the dense residential areas, research on the influence of CD method and bench method with reserved core soil when use blasting excavation method on the surface buildings by finite element method. The suitability of two kinds of blasting excavation method in the urban shallow tunnels is analyzed and compared, eventually determine the CD method with blasting excavation is more suitable for the urban shallow tunnel construction, it provides reference and suggestion for future similar construction methods that tunnel construction under the city.
Study on Simulation Analysis of Excavation Deep Foundation Pit in Qingnian Road Station of Tianjin Subway Line 2
Authors: Bai Yang , Cui Peng Bo , Wu Jing Bo , Wu Lei
Published: July 2014

On the basis of hydrogeology data,Mohr-Coulomb constitutive model in software MIDAS GTS was employed to simulate excavation deep foundation pit in Qingnian Road station of Tianjin subway line 2 after each excavation step of different construction procedures.It is positive scinentifcity for simulating excavation pit ahead of time and predicting its deformation and displacement characteristics in the foundation pit,and it is significant for the timely revision of the schemes in the next construction process.
The Dynamic Response of Shallow Buried Structure under the Action of Explosion Load
Authors: Zhang Qian , Wei Hai Bing , Zhao Jun Hai
Published: July 2014

Simulating and analyzing the dynamic response of the shallow underground structure under the ground explosions by LS-DYNA. The results show that the ground shock under ground explosions contains two different forms, one is direct impact ground shock and the other is indirect impact ground shock; with the increasing of depth, the ground shock decreases. The effective stress of the upper part of the roof is larger than other parts of the shallow underground structure; the effective strain of the corner of the roof is larger than other parts of the shallow underground structure.
Discussion on Highway Tunnel Monthitoring Measurement Control Standards
Authors: Tan Long Jin , Zhou Hong Qing , Chen Kai Sheng
Published: July 2014

Tunnel monthitoring reference value is an important indicator to determine the stability of surrounding rock. Existing tunnel specification vault settlement and surrounding convergence gives some guidance views, But in the actual project also found a number of problems, And no indication of surface displacement control reference value specification in. Based on the analysis of relevant norms, In practical engineering, for example, Monthitoring and Measurement standards for construction tunnel some meaningful discussion.
Study on Deformation Prediction of the Tunnel Surrounding Rocks Based on Non-Equal Time-Interval Grey Model
Authors: Geng Peng Fei , Yang Chang Min , Guo Wei Dong , Wang Peng
Published: July 2014

The thesis develops an non-equal time-interval GM (1, 1) model to forecast the deformation of the tunnel surrounding rock. A program is compiled via MATLAB 7.1 platform to implement the model. With the assistance of the program and the monitoring record of the convergence, the deformation is predicted and the error is analyzed. The numerical results indicate that the non-equal time-interval GM (1, 1) model does well in predicting the deformation of tunnel surrounding rock and is worthy to put into use in tunnel engineering.
Mechanical Calculation for Collapse Mechanism of Surrounding Rock on Shallow Tunnel
Authors: Peng Ying , Yang Jun Sheng , Shen Yan Hua , Liu Jian Hua
Published: July 2014

The upper bound method of limit analysis is used for surrounding pressure calculation of shallow tunnel. Two rigid-block translational collapse mechanisms are assumed for shallow tunnel and the corresponding formulas are deduced. The earth pressure of shallow tunnel has been transformed into a mathematic optimization problem, we can get optimization solutions for the surrounding rock pressure by corresponding calculating program. It is concluded that the upper bound method of limit analysis is a feasible approach for the determination of surrounding pressures on shallow tunnel.
Tunnel Collapse Treatment Technique Research in Xinjiang Tianshan High-Altitude, Low-Temperature Mountain
Authors: Zhu Chun Sheng , Yang Xiao Hua
Published: July 2014

Based on YuXiMoLeGai tunnel in G217 Cholma to the Nalati highway, aiming at the outlet section of K723+911~K723+919 collapse, through model experiment and numerical calculation combined with on-site measurement, the article studies tunnel collapse treatment technique and technical effect in xinjiang tianshan mountains in the geological conditions of high altitude, low temperature, crushing of rock mass and rock rich in water. The results show that after the CRD method, expanding the scope of the grouting construction, increasing the number of small duct grouting lock foot, strengthening methods of supporting parameters are adopted, vault subsidence deformation rate is 0.4-1.5 mm/d, peripheral convergence deformation rate is 0.5-2.2 mm/d, stress the most unfavorable right hance monthly increase in stress and strain amplitude is 3.97% and 2.35% respectively.The treatment controls the land slide body deformation and stress well.
Comfortable Quality Analysis of Subway Station Vibration Induced by Multiple Trains
Authors: Zhang Bing Qing
Published: July 2014

With more and more subway lines in cities, people have pay much attention to the comfortable quality of subway vibration, especially in transfer stations or stations that have more than one line which platform and floor have much violent vibration. The paper bases on a subway station with multiple trains, builds the finite model, puts measured wheel-rail force as the load and gets the dynamic responses. Then it accords conventional international standard of comfortable quality which uses weighted root mean square acceleration as index to evaluate the comfortable quality of platform and floor or other areas. The result shows: The station could meet the requirement of comfortable quality.
Optimization of Tunnel Support Type through Fault Zone
Authors: Li Ke , Guo Han
Published: July 2014

The mechanical properties of tunnel surrounding rock in fault zone is usually quite weak, and the support pressure and displacement are larger than other sections, so the support type in fault zone is a critical issue for tunnel safety. Three types of tunnel support through fault zone were analyzed by finite element method (FEM): ①Reinforced concrete support, ②bolting-shotcreting and reinforced concrete support,③grouting and reinforced concrete support. The result shows that support stress and surrounding rock displacement with grouting and reinforced concrete support is quite smaller than the other support types.
Key Construction Technology of Shield Machine Passing through the Airport Apron in Shallow Soft Soil
Authors: Li Run Jun , Shan Ren Liang , Li Run Sheng , Lv Jin Yang , Song Yong Wei
Published: July 2014

It is a hard engineering problem for the shield machine passing through the capital airport apron in shallow soft soil. Tunneling parameters were obtained from the 50m simulation test section ahead the apron. The shield machine kept tunneling steady and balanced by optimizing the control technology of soil pressure and grouting. According to the monitoring results, the secondary and repeated grouting technology was applied timely. The deep splitting grouting technology was used when the monitoring value exceeding control standards. The settlement value was effectively controlled.
Optimization of Construction Method for Shijiazhuang Xinbai Subway Station
Authors: Gao Chun Yan , Niu Jian Guang , Geng Dong Yang
Published: July 2014

To choose an appropriate construction scheme for subway, it,s feasible to use fuzzy optimization theory and comprehensively consider the security of four construction methods as well as such factors as environmental influence, construction period, construction difficulty and construction cost, etc. to set up a mathematical model for the construction method of subway station. An analysis is made on the impact of group-effect in the excavation construction of pilot tunnel presented in PBA construction method on arch crown settlement and ground surface settlement, and a study is made on the arch crown settlement and ground surface settlement caused by the four construction methods in construction process. In addition, a contrastive analysis is made to draw a conclusion that PBA construction method is the most suitable construction method for Xinbai Square Subway Station in Shijiazhuang.
Identification of Surrounding Rock Parameters Based on MSVR
Authors: Li Xiao Long , Zhang Jun Jing , Wang Fu Ming , Zhang Bei
Published: July 2014

An inversion method based on multi-output support vector regression (MSVR) is proposed for identifying the mechanical parameters of surrounding rock. This method considers the surrounding rock as a multi-output system during excavation, and the surveyed rock deformations of each monitoring section as its output. First, perform numerical experiments based on the principle of orthogonal test to obtain the calculated deformation values corresponding to different rock parameter combinations, and use them as the samples for training the model of MSVR as reflecting the nonlinear mapping relationship between rock and its deformations. Second, use the PSO to seek the optimal rock parameters based on measured deformations of rock mass. An example is employed to test the presented inversion method. The results showed that compared with the inversion method based on single-output support vector regression (SSVR), the proposed one is more inclined to reach the global optimization goals and achieve more reliable inversion results due to its consideration of the inherent correlativity among the measured deformations of each monitoring section.
Approach on Pollution Gases Diffusion Path of Small Spacing Tunnel Entrance Based on CFD
Authors: Xing Yan Ying
Published: July 2014

Small spacing tunnel due to the special structure form and two tubes are only separated by a thin wall. This structure form is likely to cause secondary pollution, pollution gas discharged into the adjacent tunnel. This phenomenon will lead to increased ventilation system energy consumption. This paper analysis gas diffusion path between two adjacent tunnels, using CFD (Ansys Fluent). To relieve the pollution gases secondary pollution of tunnel portal area, using CFD analyzed gas diffusion path under different circumstances, for opening hole on the top of sunshades, extended of the wall between two adjacent tunnels and other programs, and identify more comprehensive disposal program.
LS-SVM-Markov Model for Tunnel Deformation Prediction
Authors: Cai Gao Tang , Hu Su Juan
Published: July 2014

In order to effectively predict aspects of tunnel deformation, taking effective and timely measures against the problem to ensure the safety of tunnel ,LS-SVM-MC model is proposed . Namely, Markov chain based on LS-SVM corrects the error, and ultimately improves the accuracy of prediction. By the analysis and calculation of deformation prediction of a tunnel , you can find that the method is more in line with the actual situation, showing predictive superiority and a high prediction accuracy.so the method can serve as a new ways of tunnel deformation prediction,some promotional value can be gained in later work.
Optimization of Stope Structural Parameters in Phosphorite Mine and its Stability Analysis
Authors: Li Xiang Xing , Li Ke Gang
Published: July 2014

A mine plans to exploit the low dip thin phosphate deposit by room-and-pillar mining. But a township highway is just above the orebody, and its distance is only 80m, in order to better control the ground pressure in stopes and ensure the operation security, the size of room and pillar must be reasonably designed to maintain the stability of stopes and surrounding rock. The 3D-σ numerical simulation method was applied to analyze the surrounding rock stability in different stope structure parameters. The results show that when holding the size of pointed prop unchanged, the surrounding rock stability would decline with the increase of room width and pillar spacing, for security, the mining plan, the pointed prop is 3×3 m, the stope width and pillar spacing is not more than 9 m, were considered to be one of the optimal. In addition, it is important to emphasize that if the mining depth exceeds 300m, some methods, such as decreasing the spacing of stope and pointed props or increasing the pillar size, need to be taken to avoid the stope instability caused by greater ground pressure.
Research on Defects of Tunnel Portals during the Operation
Authors: Zhu Ku Zhu , Luo Jian Hang
Published: July 2014

Through the site investigation of defects on a secondary highway tunnel portal in Guizhou Province and survey data, this paper aims to analyze the detection mechanism of all defects. Controlled by bias effect of tunnel portals, the defects of portal lining cracking and leakage are pretty serious. A fully understanding of these mechanisms can help to improve and fine design and construction of tunnel portal, reducing the production of defect.
Auger Bored Piles Application Works in the Subway
Authors: Wu Yang
Published: July 2014

Pile Foundation Construction jobs are usually wet process has contaminated a large, long duration, the pile of inconsistent quality, cost out. And long bored piles to adapt to a variety of complex geological conditions, but not the impact of water table, is widely used in various projects of the foundation engineering, this according to subway construction in Kunming, the application of experience, a brief description length screw pile construction anti-interpolation technology.
A Numerical Investigation on Time-Dependent Failure of Tunnels Based on the Long-Term Strength Characteristics of Rocks
Authors: Li Lian Chong , Xing Meng
Published: July 2014

How to establish the proper rheological model to describe and simulate the relationship between rock mechanic characteristics and time is one of the difficulties in the tunnel long-term stability analysis. In this paper, a numerical model to replicate the time-dependent deformation of rock mass was presented. In the model, the time-dependent deformation is described in terms of degradation of intrinsic physical and mechanical properties of rock and accumulation of mesoscopic damage inside the rock. Based on the model, uniaxial numerical experimentation and tunnel numerical model test are numerically constructed and investigated respectively. The model well reflects the initial creep, steady creep of rock and accelerated creep, which preliminary prove the validity of the proposed model. The results of the tunnel numerical model test show that the displacement curves from the numerical simulation were generally consistent with those from physical model tests. Furthermore, the macroscopic failure modes and local mesoscopic damage evolution of the tunnels were simulated.
Study on Pressure Observation of Fully Mechanized Caving Faces in Coal Seams with Rock Burst Danger in Xiagou Coal Mine
Authors: Tian Zhi Chao , Liu Ye Jiao , Wang Wen Cai , Ren Yu Hui
Published: July 2014

Taking the first fully mechanized caving face in Xiagou coal mine as research background, through the pressure observation on the scene field of fully mechanized caving face with rock burst danger, this essay reveals the pressure appearance law of coal seams rock burst danger and concludes that the field roof structure of fully roof mining is more conducive to the release of coal rock stress compared to layered mining structure and this method plays a mitigation role on moving pressure shock of coal rock. The fully mechanized caving faces can be explored fast under safety conditions. The research results are of great theoretical and practical significance to the mining production with similar geological conditions.
Application of Grouting Reinforcement Technology in Pingshan Shaft Station
Authors: Tian Liang , Xi Jing Yi , Liu Jian , Liu Xiao Dong , Shang Feng , Dong Xun
Published: July 2014

Support of soft rock is a big challenge in all mines at home and abroad. Soft rock is of different kinds of rheological property for geological conditions, mine ground pressure and so on. It brings about really difficult problem to roadway support. In order to ensure safety application and prolong usage, shaft station need to be reinforced. Sight instrument was used to analyze broken conditions. The results show that the broken depth in roof rock is 5~6 m, and greater than 4 m in sidewalls. According to failure characters and sight results, we determine that rock of shaft station belongs to high geo-stress and jointed soft rock. On this basis, technology of grouting reinforcement combined with cable anchor support is carried out. Monitoring results of surface convergence and cable force show that bearing capacity of surrounding rock increases obviously, roadway contraction and floor heave are well controlled.
Reliability Analysis on the Foundation Bearing Capacity in Ningbo Rail Transit Engineering
Authors: Zhu Jian Feng , Liu Gan Bin , Ye Jun Neng
Published: July 2014

According to the first-stage geologic investigation reports of the line 1 and line 2 in Ningbo rail transit, the natural density (ρ) and the vane strength (Cu) probability distribution of the typical layers in Ningbo area were studied in this paper. Besides, the reliabilities of the typical layers foundation bearing capacity in Ningbo area were evaluated by the checking point method. It is found that (1) the natural densities of the typical layers in Ningbo area show good normal distribution as their corresponding variation coefficients (δ) are small. Unfortunately, the vane strengths of the typical soils in Ningbo area show poor normal distribution as their corresponding variation coefficients (δ) are large. (2) The soil parameters variation has significant influence on the reliability index β. Moreover, β is more sensitive to the variation of ρ than to the variation of Cu. (3) As the safety coefficient methods can not consider the influence of the soil parameters variation on the foundation stability, it is suggested that the foundation stability in Ningbo area should be evaluated by the reliability analysis method.
Finite Element Analysis on Causes of Crack in Large Underground Garage
Authors: Shu Bin , Peng Jian He
Published: July 2014

The paper aims to solve the serious and regular crack problems in underground garage. ANSYS finite element software is applied to set up the overall finite element model on floor-foundation and foundation coupling beam-foundation soil in underground garage. Combined with engineering field detection, factors influencing underground garage floor like underground water level, soil expansion caused by water content change in expansive soil, soil poisson ratio, foundation settlement are taken into consideration to find out the causes of cracks. The study is expected to provide reference for similar cases in other projects.
Subway Station Group Decision and Evaluation of Fire Emergency
Authors: Cao Li Jun , Yu Xiang Mei , Geng Dong Yang
Published: July 2014

In order to build subway station fire emergency group decision-making system, Aim at the subway station fire characteristics in this paper, analyze the problems of emphasis from emergency decision, and group decision method is proposed to use to solve this problem. The method can avoid failure of the overall decision making mistakes because a single decision maker. Found of decision-making group consist of experts, academics, policy-makers, considering several key factor such as professional, academic, expert ratings, weight, to build group decision model .At the same time, evaluation of the subway station fire emergency group decision effectiveness to build subway station fire emergency response system, Ultimately improve the efficiency of emergency response and level of decision-making for subway station.
Based on Effect Coefficient Method of Metro Tunnel Collapse Risk Evaluation Model and its Application
Authors: Cai Peng Lin , Wang Jia , Tian Shu Wen
Published: July 2014

Tunnel collapse is one of the most common accidents in the tunnel construction of city subway, and risk assessment is a method to measure the magnitude of the collapse risk. In order to effectively identify in advance the risk category of tunnel collapse, an identification method is put forward based on entropy weight method and efficiency coefficient method. On the basis of a comprehensive analysis of factors that affect the collapse, 6 main factors including rock level, tunnel depth, tunnel span, the surrounding conditions, groundwater and construction factors are selected as the evaluation indexes. Through a quantitative description of the evaluation indexes by using the TSP203 geological prediction system, and based on the basic principles of ideal point method, a comprehensive and intelligent evaluation model which can identify the tunnel collapse risk in subway construction is established. Finally, the model is applied to practical engineering, and it shows that the result of risk assessment is consistent with the actual construction conditions, which provides a new perspective on the advancing identification of tunnel collapse risk in subway construction.
Research on the Anchorage Technology of Steep Slope in Sanitary Landfill
Authors: Li Ping , Wang Heng , Xin Ying
Published: July 2014

The process of urbanization has brought prosperity of economy and improvement of people's living standard, but larger and larger life garbage in the city could be found due to excessive concentration of population. Sanitary landfill method has been widely applied in many cities for convenience and economy. Anti-seepage treatment and anchorage technology are two key issues to reduce the pollution of leachate on surrounding environment and underground water sources with construction of modern sanitary landfill area. In this paper, the anchorage technology of high-density polyethylene (HDPE) membrane was researched on the steep slope in the valley-type sanitary landfill. The test and theory of anchorage were also studied in the northwest region. The results show that anchorage force reaches the maximum when the anchoring platform is horizontal. It keeps the geomembrane more stable if the slope angle is within 45° when the slope height is over 6m.
Response Modification Factor for Y-Eccentric-Braced Steel Frame Structures Designed Based on Chinese Code
Authors: Yang Wen Xia , Gu Qiang , Cao Ping Zhou , Shi Rong Jin
Published: July 2014

In current seismic design procedure, structure base shear is calculated according to the linear elastic response spectra divided by the response modification factor, which accounts for ductility and overstrength of a structural system. In this paper, the response modification factors of Y-eccentric braced steel frames (YECBF) designed based on Chinese Code were evaluated by an improved pushover analysis on 12 examples with various stories and spans lengths. According to the analysis results, the effects of fundamental periods, storey numbers, and spans of frames on the behavior factor were studied. In the end, an appropriate response modification factor was proposed for YECBF designed base on Chinese Code.
Seismic Performance of the Reinforced Concrete Frame Structures with Infilled Walls of Different Configuration
Authors: Guan Min Sheng , Du Hong Biao , Chen Wei , Wu Yu Hua
Published: July 2014

Using the three-strut model, five types of frame structures, i.e., without infilled walls, with full infilled walls, without bottom-storey infilled walls, without middle-storey infilled walls and without top-storey infilled walls, were studied. The mode analysis and nonlinear time-history analysis were carried out on each model. In order to investigate the effects of infilled walls with different configurations on the seismic behavior of reinforced concrete frame structures, the structural periods, the ratio of Tt to T1 and the maximum interstorey drifts were analyzed. The results indicate that the infilled walls enhance the lateral stiffness of frames, and the configuration of infilled walls has little influence on the calculation of structural periods. It also shows that the weaker storey is formed due to the unreasonable layout of infilled walls, thus leading to the collapse of the whole structures under the seismic action.
Shaking Table Test Analysis of Bottom-Business Multi-Story Masonry Structure in Small and Middle Towns in the Southward
Authors: Liang Yong Duo , Guo Xun , Yi Hua Wei , Li Yong Zhen , Jiang Jin Zheng
Published: July 2014

Bottom-business multi-story masonry structure is widely used in small and middle towns in the southward in China. In the downtown of Beichuan county which affected by Wenchuan earthquake, more than 80% of this kind of building collapsed. But the Apartment of Beichuan Telecommunication Bureau behaved well earthquake resistant capacity with a moderate damage in the earthquake. The obvious difference between this building and others is the setting of winged columns in the front longitudinal wall of the first floor. For proving the influence of these members in the structure seismic capacity, the earthquake simulation shaking table test of 2 1/5 reduced scale models were designed and carried out. The models dynamic response, acceleration, displacement and strain were measured and collected, that model with winged columns behave well was testified. And the reinforcement method of balancing stiffness and increasing ductility is put forward. The results provide a foundation for the retrofitting design of the existing houses.
The Present Situation of Rural Housing and the Seismic Performance Analysis
Authors: Li Han
Published: July 2014

In recent years, the security of rural building has attracted more and more attention. The analysis of the existing problems of rural building summarized the distribution of dangerous points, and the use of finite element analysis method was carried out on the typical farmhouse seismic time history analysis to find out seismic weak places in the masonry structure buildings. Then the study also shows that the system with ring beam and structural concrete column has good reinforcement effect. This study plays an important role in improving the rural housing construction measures and the seismic performance of the building.
Seismic Response Analysis of Deep Water Bridges with Pile Group Foundations
Authors: Zhao Dong Xiao , Wang Jun Jie , Su Jun Sheng
Published: July 2014

In this paper, we intended to replace the fluid-structure interaction of deep water bridge piers with acceleration-dependent forces during an earthquake. The hydrodynamic pressure on bridge pier groups under seismic excitation is studied using the finite volume method. Different seismic waves with various spectrum components are selected in order to cover frequently encountered cases. The calculated forces of these cylinders are fitted into the Morison equation, and by calculation, the drag force term is negligible, thus the effect of fluid is converted into one added mass term. The paper further calculated the dynamic response of a continuous beam bridge with pier groups in water to check the validity of our proposed method.
Feasibility Analysis of Applying Biomechanical Properties of Human Body to Seismic Design of Building Structure
Authors: Wu Sha Sha , Kang Guan Chang , Wang Shao , Lian Jun Ying
Published: July 2014

With the rapid development of high-rise buildings in our country, the seismic design of structures is becoming more and more important. And the seismic performance of traditional seismic system is not perfect, there are still some room for improvement. This article points out the advantages of the human body vertebra seismic system by comparing the characteristics of the current building aseismic system with the deep analysis of the human body vertebra seismic system and the application of the seismic characteristics of the human body vertebra in seismic design of building structure application foreground is prospected.
Application of the Jerk Feedback on the Shaking Table
Authors: Li Fang Fang , Ji Jin Bao , Li Xiao Jun , Li Na
Published: July 2014

For the shaking table system, the 90o phase shift frequency of the servo valve system is close to the oil column resonance frequency, the bandwidth under the influence of servo valve features was so narrow that it cannot meet requirements. Multi-variable control is presented in this paper by introducing the jerk feedback on the basis of the three-variable control. The theoretical derivation and the system simulation show that: the jerk feedback can reduce the oil column resonance frequency, and decrease the influence of the system performance caused by the servo valve characteristics.
Permanent Displacement Identification Analysis in 2011 Mw9.0 Tohoku Earthquake, Japan
Authors: Zhou Bao Feng , Song Ting Su , Wen Rui Zhi , Xie Li Li
Published: July 2014

Permanent displacement identification is one of key topics in near-fault ground-motion research. A new method based on Hermit interpolation and flatness technique is proposed to determine permanent displacements, since the Iwan law is not applicable in Mw9.0 Tohoku earthquake permanent displacement recognition. The method is then tested by coseismic displacements resulted from GPS station nearby. Results show that: the causes for strong motion record baseline drift are very complex so that Iwan method is not suitable for permanent displacements identification in the Mw9.0 Tohoku Earthquake, while the new baseline correction method combining Hermit interpolation and flatness technique is suitable for permanent displacement analysis of near-fault ground motion in 2011 Mw9.0 Tohoku Earthquake.
Research Summary of Vibration Reducing Performance for Infilled Wall
Authors: Sun Ming She , Qu Shu Ying , Meng Fan Bo , Li Cui Ling
Published: July 2014

Infilled wall is always regarded as a nonload bearing element, its energy-dissipation capacity and impact for the frame structure under earthquake have not been taken seriously. In this paper the function of infilled wall for frame structure was discussed, energy-dissipation capacity of different measures were analysed and compared from the point of passive control theory. This paper provides the reference for the further research of filler wall.
Consolidation of Unsaturated Soils due to Dissipation of Pore-Air Pressure
Authors: Xu Hao Feng , Wang Wen Jun , Zha Zhi Xiang
Published: July 2014

One-dimensional consolidation equation of unsaturated soils was derived in order to solve this special case of consolidation. The presented equation, not similar to Terzaghi’s equation, is a type of absolute nonlinear partial differential equation, and it was solved by finite difference method. An example was analyzed and the case of incompressible fluid consolidation was compared. Finally the experimental results from laboratory tests reported in the literature, was fitted by the presented equation, and the agreement was good. The results show that (1) the process of pore-air pressure dissipation is similar to that of pore-water pressure of saturated soils; (2) the compressibility of pore fluid is not an advantageous factor to quicken the consolidation; (3) the presented equation is effective to analyze the process of consolidation of unsaturated soils which consolidate mainly due to the dissipation of pore-air pressure.
Study on Seismic Detection Applied in Mine Advance and Side
Authors: Hu Yun Bing , Wang Yao , Wu Yan Qing , Liu Zi Xuan
Published: July 2014

This paper mainly discusses that the tunnel seismic advance detection is applied in mine geo-hazard detection. Separating the field seismic data of mine by radon transformation and migrating the data through advance way and side way, we accomplished advance and side detection simultaneously by one-time shot seismic data. Case study was carried on at Qinshui basin Yangmei No.5 mine field, and detection results mainly coincide with out-crops, demonstrating that our method can be one reference in mine geo-hazard detection.
Dynamic Analysis of Artificial Boundaries in Gravity Dam-Foundation Rock Interaction System
Authors: Qiao Wen , Liu Guo Ming
Published: July 2014

ANSYS was used to focus on comparative analysis of several artificial boundary conditions that are widely used in engineering applications. The accuracy and stability of dynamic analysis results were then analyzed in details of a semi-infinite foundation with different artificial boundaries and different frequency input loads. Lastly, the seismic response of a gravity dam-foundation rock system was explored numerically. Experimental results revealed the simulation accuracy of artificial boundaries was closely related to the dynamic characteristics of input load and the elastic wave velocity. When the input load frequency was high, only the material with comparably higher elastic wave velocity could maintain the stability of the artificial boundary. Viscoelastic artificial boundary is practically simple and can better simulate the semi-infinite material elastic recovery ability and energy radiation outside the boundary.