bluuebunny/crossref_metadata_2025 huggingface dataset:
Hysteresis Observer Design of Sliding Mode Control for Piezoelectric Actuators
Authors: Wei Qiang , Wu Shun Wei , Zhang Dong , Liu Lei
Published: August 2013

Piezoelectric actuators (PEAs) have been widely used in micro fabrication. But the hysteresis inherited in PEAs leads to a severe inaccuracy and deteriorated tracking performance. In this paper, a hysteresis observer is designed for PEAs to estimate the hysteresis, mechanical parameter varieties, positioning error and external disturbance. A Bouc-Wen model is associated with a linear second-order mass-damping-spring trio to model the dynamics. An asymptotic sliding surface is selected. Lyapunov stability theory is applied to guarantee the asymptotical stability for the trajectory tracking error. Experiments are conducted to validate the effectiveness of the proposed method. Results show that a satisfied tracking response to a sinusoidal trajectory is achieved, and the positioning errors under a triangle scanning contour are dramatically reduced compared with the traditional SMC.
Research on Integrated Monitoring System of High-Voltage Tower
Authors: Huang Hui Chun , Jiang Wei , Hu Ren Jie
Published: August 2013

The monitoring and stable operation of high-voltage tower is an important direction of strong grid research. Transmission monitoring includes the forecast of early faults and real-time state estimation. There is no domestic report on related research. Some simulation in laboratory had been done and little been reported. The research review was carried out in accordance with existing knowledge and research progress summary, using wireless transmission and self-generating as example, to build high-voltage tower monitoring system including power management systems, sensor systems, data processing systems, signal transmission system and remote monitoring system.
An On-Chip Clock Controller for Testing Fault in System on Chip
Authors: Lin Wei , Shi Wen Long
Published: August 2013

In this paper, an on-chip clock (OCC) controller with bypass function based on an internal phase locked loop (PLL) is designed to test the faults in system on chip (SOC), such as the transition-delay faults and the stuck-at faults. A clock chain logic which can eliminate the metastable state is realized to generate an enable signal for the OCC controller, and then, the test pattern is generated by the automatic test pattern generation (ATPG) tools. Next, the scan test pattern is simulated by the Synopsys tool and the correctness of the design is verified. The result shows that the design of at-speed scan test in this paper is high efficient for detecting the timing-related defects. Finally, the 89.29 percent transition-delay fault coverage and the 94.50 percent stuck-at fault coverage are achieved, and it is successfully applied to an integrated circuit design.
Application and Research on On-Line Automatic-Monitoring Platform of Radiation Sources Based on the Data Communication Optimization
Authors: Yang Dong Li , Yang Bin
Published: August 2013

This thesis summarized the content of IOCP( I/O completion port ). It was improved in connection with the defect that is data communications more occupation on server system resources and its poor parallel processing ability, in the original on-line automatic-monitoring platform. It improved the shortcomings of the original data communication through the package IOCP model. And we launched an exploratory study about the package IOCP model.
Active Feedback Control Used in Plasma Vertical Unstable Displacement for EAST
Authors: Huang Hai Hong , Wang Ye , Wang Hai Xin
Published: August 2013

EAST (Experimental Advanced Superconducting Tokamak), a National Mage-project of Science Research of China, is a very important fusion experiment facility. The ability of magnetic confinement to plasma can be improved by elongating plasma cross-section to form divertor configuration in EAST. But elongated plasma has vertical displacement instability, without control, plasma will dash against wall of vacuum vessel and disrupt, that will cause failure of plasma discharge. So feedback control system is needed to restrain plasma vertical displacement. Fast control power supply excites active feedback coils, which produces magnetic field to control plasmas displacement. The validity of proposed scheme was confirmed by experiments, the active feedback system can reach design demand.
Study on the Applications of FBG Technology in River Level Monitoring
Authors: Tan Dong Jie , Han Bing , Wang Bao Yan , Li Liang Liang
Published: August 2013

In order to overcome the disadvantage of low accuracy for traditional monitoring technologies of river level, and solve the problems in real-time data acquisition and remote transmission for the existing hydrological observation, we design a new monitoring system of river level based on fiber grating technology, which can realize high sensitivity and automatic monitoring of river level. The system has been put into practical application in a monitoring project and the measurement results indicate that this system is of such advantages as real-time capability, high accuracy, unattended operation, and can well meet the present requirements of hydrological observation and measurement.
The Research about No-Vibration Data Storage of Micro-Scale and Long-Term Ocean Turbulence Measurement
Authors: Luan Xin , Xue Bing , Sun Feng Mei , Yan Qi Zhi , Song Da Lei
Published: August 2013

Turbulence played an important role in the evolution of the seawater energy and exchange. Multi-scale, long-term, fixed-point and continuous sampling is a new research direction in the turbulence observation. This dissertation designed high-capacity and no-vibration data storage solutions aiming at long-term, continuous turbulence observations. First a multi-scale submerged buoy observing platform is designed. Base on the turbulence observing platform, a multi-parameter data acquisition and no vibrations storage system is designed. This paper describes the hardware and software design implementation of large-capacity data storage arrays in details as well as the readability and easy operation of the transplant of FatFS. Actual test and sea trial prove the design can be achieved large-capacity data access of long-term observation of ocean turbulence base on the submerged buoy.
Research on Web3D in Distributed Monitoring and Control Systems
Authors: Zhang Xing Lin , Du Yu Yue , Jiang Xia
Published: August 2013

Web3D technology, with the advantages of realistic scene simulation and intelligent interaction, has been widely applied to many fields, like electronic business and medical treatment. Aiming at the problems of abstract information and poor interactivity in traditional Distributed Monitoring and Control Systems (DMCS), a method based on Web3D technology is presented. The services published by DMCS are called to deal with the request before the scene management, and then the effective messages are asynchronous transferred by the way of Ajax which can optimize the real-time scene interaction. The objects designed by JavaScript map the messages into entities in VRML/X3D scenes. Simulation analysis demonstrated the effectiveness of realistic scene simulation and high performance of intelligent interaction.
Research and Application of Automated Testing Tool Based on STAF
Authors: Shang Yu , Zhang Xiao Li , Feng Yan Bin , Li Mo Mo
Published: August 2013

To improve the efficiency of automated testing, reduce testing spending, This article brings out a new automation testing frameworkWTAF, and automated regression testing is the focus of the study. First of all, we choose the open source automation framework STAF for regression testing , And then utilize STAF services to link all testing process implemented during the regression testing. Using automation testing technology, WTAF can successfully solve the low efficiency problem existed in manual or semi-automation testing.
Research on the Joint Detection of TD-SCDMA
Authors: Fu Hai Yang , Wang Qun , Jia Xiang Dong , Liu Kai
Published: August 2013

Joint detection (JD) is a core technology of TD-SCDMA system. Only many mathematical models of JD have been proposed and discussed in many references, but there is no a physical model of JD for application. So the concept of JD is not clear. The concept of JD is made clearer by its principle and algorithm with physical model presented in this paper. Also a method for eliminating multi-path interference (MPI) by using mid-amble sequence and frequency spreading code (FSC) would be presented, and a JD constructed by that method would be proposed in the paper.
Application of ANN in Hydraulic Pressure Control Fault Diagnosis System
Authors: Zhang Xiao Yu , Ding Li Li
Published: August 2013

The existing hydraulic pressure control fault diagnosis system is effective on fault detection, but the fault isolation capability is bad. In order to improve the capability of the fault isolation, the artificial neural network (ANN) is used in the fault diagnosis system. Aimed at the representative diagnosis of the hydraulic pressure control system, the three layers feedback network is adopted, the basic theory of conjugate gradient BP neural network is explained in detail, and the key techniques are introduced. Five types of typical faults of hydraulic pressure control system can be distinguished easily by it, the faults diagnosis efficiency is higher 30% than ever and the fault diagnosis capability is better 80% than before.
The Boundary Element Method of Testing Wood Moisture Content Problem in the Heterogeneous and Asymmetric Case
Authors: Guo Cui , Luo Yue Sheng , Ge Bin , Liu Shao Gang
Published: August 2013

In this paper, we discussed this engineering problem that used planar capacitance sensor measuring lumber moisture content. And a new mathematical model was introduced which could set up the relationship between the distribution of dielectric constant and planar capacitance sensor in the heterogeneous asymmetric cases. At the same time, the numerical example was given and we matched the function of capacitance value and dielectric permittivity of medium. Accordingly, through measuring capacitance value of capacitance sensor, we could get the distribution situation of dielectric permittivity, thus obtaining the moisture content distribution of media such as wood. It could not only greatly cut down measuring work, but also avoided the waste of media resources, such as wood.
Application of Fuzzy Neural Networks on Missile Launcher Fault Prediction
Authors: Cai Gui Fang , Hu Fan Jun
Published: August 2013

In order to improve the reliability, security and validity of such type Missile Launcher, The faults prediction theory is introduced based on fuzzy neural network. The faults prediction analysis model is built, and an advanced training algorithm is proposed. Such algorithm is tested by using in the fault prediction of the missile launcher. The Experiment results illustrate that by using the proposed model, the faults prediction speed is faster 80% than ever, the prediction veracity is advanced, and the cost is reduced to 50%.
Wireless Sensor Network Fault Diagnosis Method of Optimization Research and Simulation
Authors: Li Qiang
Published: August 2013

The traditional method of wireless sensor network fault diagnosis based on linear modeling rather than actually complicated and nod-linear relationship results in error data and leads to wrong decisions, therefore, this paper presents a sensor fault diagnosis method based on ARIMA and LSSVM integration control system which used to diagnosis sensor fault whose results are input LSSVM to fusion and get the final results of fault diagnosis. The simulation test results show that the proposed method improves the sensor node fault diagnosis accuracy, reduce the false negative rate and false positive rate.
The Debris Flow Disaster Faster-Than-Early Forecast System (DFS) with Multi-Sensors Integrated Wireless Sensor Networks
Authors: Zhao Rong , Li Cai Hong , Tan Yun Jian , Shi Jun , Mu Fu Qiang , Chen Xiao Fan , Li Lian
Published: August 2013

This paper presents a Debris Flow Disaster Faster-than-early Forecast System (DFS) with wireless sensor networks. Debris flows carrying saturated solid materials in water flowing downslope often cause severe damage to the lives and properties in their path. Faster-than-early or faster-than-real-time forecasts are imperative to save lives and reduce damage. This paper presents a novel multi-sensor networks for monitoring debris flows. The main idea is to let these sensors drift with the debris flow, to collect flow information as they move along, and to transmit the collected data to base stations in real time. The Raw data are sent to the cloud processing center from the base station. And the processed data and the video of the debris flow are display on the remote PC. The design of the system address many challenging issues, including cost, deployment efforts, and fast reaction.
A Proposed Hybrid Wireless Sensor Networks Deployed on the Sea
Authors: Gao Ai Guo , Luo Xiao Lin , Luo Han Jiang
Published: August 2013

Wireless sensor networks are envisioned to perform monitoring tasks over the large portion of the world covered by oceans. However, deploying wireless sensor networks on the sea poses many challenges. To deal with the problems, we proposed a hybrid wireless sensor networks deployed on the sea which combines the advantages of wireless sensor networks (WSNs) and Underwater Acoustic Sensor Networks (UWA-SNs ) together. In this paper, we first introduced the structure of the double-head sensor node, and then discussed the applications of the hybrid networks, such as ocean monitoring, test bed and intrusion detection. We also present the analysis of deployment of the hybrid sensor networks.
Rainfall Threshold of Rainfall-Induced Landslides Based on Laboratory Test
Authors: Su Yan , Qiu Jun Bing , Du Yue Ting
Published: August 2013

A landslide model test under the artificial rainfall was built according to the rainfll-induced landslide in Fujian mountainous area. The rainfall intensity, the slope types (mainly on vegetation coverage) and the grade of side slope were the main factors in the test. The rainfall threshold of rainfall-induced landslide on shallow bedrock was obtained from the test. The relationship between the cumulative precipitation and slope angle and slope surface types was analyzed from the orthogonal experiment by multiple regression analysis. Results show that most slope failures are caused by the infiltration of rainwater. Conclusion show that when the slope angle and vegetation cover are given, critical hazard threshold can be predicted, and the corresponding landslide sliding time can be gained by combining with the rainfall intensity.
A Soil Stratifying Method Based on Piezocone Penetration Test
Authors: Xu Xu , Zhang Fu You , Gu Ming
Published: August 2013

This paper introduces the empirical method of classifying soil layers with CPTU. Pore pressure dissipation test was taken in a certain soft clay field, according to the characteristics of penetration curve and the value of static point resistance, frictional resistance, friction-resistance ratio, soil horizon was divided. According to the characteristics of the pore pressure dissipation test curve of different depth, weak interlayers was further surveyed.
Prestressed Anchor Bolt Impact on the Deformation of Composite Soil Nailing
Authors: Wang Deng Qun , Zhu Yan Peng
Published: August 2013

Finite element software was employed to establish a model to simulate the compound soil nailing. The model simulates the process of constructing prestressed compound soil nailing. Compared the condition prestressed with no prestress, analyzed the Impact of prestress anchor on the deformation in the process of construction and the effect on axial force of soil nail. Applying prestress is able to control the horizontal displacement obviously, but has not obvious effect on vertical displacement, especially place the anchor bolt at the lower part of the slope. In the process of construction, prestress has an advance effect on the deformation of foundation pit and the axial force of soil nails near the anchor bolt.
Nonlinear Consolidation Analysis of Stone Column Composite Ground under Time-Dependent Loading
Authors: Hu Yan Ran
Published: August 2013

A few solutions for stone column composite ground consolidation have been presented which ignoring the nonlinear characteristic of surrounding soil or the variation of upper load with time. Considering the nonlinear characteristic of surrounding soil, variation of upper load with time, distribution of permeability coefficient in smear zone, the governing equation for consolidation of composite ground is obtained. The equation is solved using separation of variables method. Finally, the influence of parameters on consolidation rate is discussed.
Relationship between Dynamic Modulus and Static Detection Index in Red Sandstone Subgrade
Authors: Chen Chong , Zheng Jian Long
Published: August 2013

The portable falling weight deflectometer (PFWD) test, bearing plate test, beckman beam test, and compaction test were carried out in this study. The relation of dynamic modulus and static modulus, dynamic modulus and deflection, dynamic modulus and compaction ratio, dynamic modulus and water content (consistency) was built. It turns out that there are good power function regression relationship between dynamic modulus and static modulus, dynamic modulus and deflection, dynamic modulus and compaction ratio, dynamic modulus and water content and consistency.
Key words: red sandstone; dynamic modulus; resilient modulus; deflection; compaction ratio; water content
Response and Test of Whole Space Transient Electromagnetic Field in Mine Goaf Water
Authors: Xue Yi Guo , Li Shu Cai , Su Mao Xin , Li Hai Yan , Tian Hao
Published: August 2013

The transient electromagnetic method (TEM) has sensitive characteristics of low resistivity of water containing. The equivalent plane method based on whole space theory is used in coal mine goaf water TEM detecting. The mine goaf water was forward simulation. The geoelectric model of mine goaf water was equivalented to low resistivity layer thickness. The geoelectric model was forward calculated, and it was differential imaged. Then it found the apparent longitudinal conductance differential imaging reflect the most sensitive. The field experiment was conducted in two mine goaf water in Xiezhuang coal mine. The central loop device was selected as working device. The launch wire frame is length of 2m and 8 turns. A receiving device is receiving probe and the effective area is 212m2. The Water distribution range of goaf water in-300 of the seven mining area in front of retaining wall is large, and the water body is deep.
A Prediction Model of Loess Collapsibility Base on the Method of Fuzzy Information Optimization Processing
Authors: Ma Yan , Wang Jia Ding , Peng Shu Jun
Published: August 2013

For establishing a prediction model of collapsibility loess for central region of Shanxi Province, 48 groups of loess collapsibility test data have been collected from Taiyuan-Jinzhong area. The mechanism of collapsibility were discussed and based on that the moisture content,void ratio and compressibility were chosen form the test data to be the basic parameter for establishment of prediction model by the method of fuzzy information optimization processing. 40 groups of test data were used to establish the model and 8 groups of test data were used to validate the correctness and applicability of the prediction model. From the validation, the correctness and applicability loess collapsibility prediction model has been confirmed. This method is simple, efficient and practical, which can be applied to evaluate the collapsibility of the loess in Taiyuan-Jinzhong area for future construction engineering.
Study on the Engineering Geological Properties of Drill Hole in North Yellow Sea
Authors: Liu Xiao , Feng Xiu Li , Liu Jie
Published: August 2013

The North Yellow Sea basin was located in the middle of the North Yellow Sea. It was possible to find oil and gas reservoirs in this area according to different researches. It was also an oceanic area studied little. In this paper, the engineering geological properties of a drill hole samples collected in the middle of the North Yellow Sea Basin was studied, which could provide basic data for engineering construction and oil and gas exploration and development in this area. In result, stratum of the study area can be divided into 9 units; the mechanical properties of cohesive soil are poor, which have the feature of high compressibility and low shear strength; Granular soil, especially unit 9, has high strength and good engineering property, which is appropriate for use as bearing stratum for drilling platform and other ocean engineering.
Progress in Platinum Group Element (PGE) in Black Shale Series
Authors: Liu Jun , Chen Ying , Liao Zhen Xiu , Zhan Yong , Guan You Fei
Published: August 2013

The black shale enriched in various precious metal elements and platinum group elements. And the PGE deposit in black shale series is a new promising mineral resource. Comprehensive research on the geology, geochemistry, petrology, mineralogy, fluid inclusion and geochronology of the PGE in black shale series has been carried out and made a series of achievements. This paper summarized the advances in PGE in black shale series and pointed out the controversial views about the source of the PGE.
Study on the Relationship between Deformation and Stability of Large Landslide with the Rainfall
Authors: Lu Jian Hong , Qin Jiang Hong
Published: August 2013

Prediction problem of large catastrophic landslide is an important applied research topic of geotechnical mechanics. This paper made the detailed geology survey and analysis for the Xiapuzi landslide; based on the analysis of the rainfall data, analyzed landslide body stability under rainfall influence. Using deformation monitoring data,relationships were analyzed between rainfall infiltration time, critical rainfall and total rainfall,with the deformation of landslide, and the relationship between deformations incremental with the rainfall. Results provided a basis for choice of landslide treatment measures. The research accumulated experience for treatment of similar landslide geological disasters.
Consolidation Settlement of the Modern Yellow River Subaqueous Delta
Authors: Liu Jie , Feng Xiu Li , Liu Xiao
Published: August 2013

In this paper, the consolidation settlement and settlement rate were studied based on the drilling data of the Yellow River subaqueous delta. The results show that surface sediments of ZK-2 are significantly coarsen than ZK-1, and correspondingly with varying physical and mechanical properties in different cores. Based on the one-dimensional consolidation theory, 50m thickness of layer could produce a total of 1.70m settlement in ZK-1, and 60m could produce 2.34m settlement in ZK-2. The consolidation settlement of unit depth is at 0.1~9cm/m. The consolidation degree needs about 15~20 years to reach 90% and the average sedimentation rate is at 7-9cm/a.
The Application of Measurement Robot in Landslides Emergency Monitoring
Authors: Lu Shu Qiang , Yi Qing Lin , Yi Wu
Published: August 2013

The measurement robot (TCA2003 Total Station) has been adopted to solve the problems of landslides emergency monitoring. The working principle and characteristics of measurement robot were briefly introduced. Then a main frame of the deformation monitoring system based on measurement robot was presented and the corresponding software was designed. Based on the GPS deformation monitoring system, the measurement robot automatic emergency monitoring system were established. The application of measurement robot in deformation monitoring system for landslides of the Three Gorges was mainly studied in this paper. The method of monitor landslide by the robot deformation monitoring system has several advantages and extensive application foreground.
Experimental Study on the Time Effect of the Jacked Pile
Authors: Wang Rui Cai , Shi Jian Yong , Chen Sheng , Chen Hua Jie
Published: August 2013

Based on the strain-holding test by using GDS stress path triaxial apparatus, the changes of pore water pressure and stress of soil around the pile were simulated during and after pile jacking. Test results show as follows: excess pore water pressure and effective stress increment increase with strain and initial stress rising at the stage of strain applied. And at the stage of strain holding, effective stress increment increases with rising of strain and initial stress. For the total effective stress increment, the proportion of effective stress increment is large at the stage of strain applied. And at the stage of strain holding, the proportion of effective stress increment is small.
Fatigue Damage Model of Limestone Based on Dynamic Elastic Modulus Attenuation Rule
Authors: Zhao Kai , Han Zhi Ming , Yang Xing Wang
Published: August 2013

For exploring the attenuation law of limestone dynamic elastic modulus (DEM) under fatigue cyclic loading, 24 limestone specimens were used to conduct dynamic uniaxial cyclic compressive tests under different loading frequencies and stress amplitudes on MTS Test System. The tests results confirmed that the decrease of DEM goes through three different stages with the increase of cyclic numbers. And, there is no distinct correlation between three-stage evolution rule of DEM and frequencies as well as stress amplitudes. The degeneration of DEM is caused by accumulation of micro-cracks and damage increase in rock specimen. Thus, based on attenuation rule of DEM, a fatigue damage evolution model which can depict the first two stages of limestone fatigue damage development was proposed.
Simulation of Electric Field Distribution in Concrete of Pulse Electro-Osmosis Technology Based on ANSYS Software
Authors: Zhu Jiang Miao , Li Zhi Xin , Wang Ying
Published: August 2013

Simulated electric field distribution in concrete by using of ANSYS finite element analysis software, researched influences of some factors on electric field strength and electric potential in concrete. Which include resistivity of cement soil and its electric field strength are inversely proportional and the electric potential distribution is less affected by resistivity changes, applied voltage is proportional to electric field strength and potential, the more the number of cathode induces the greater and uniform of the strength, electric field distribution within cement soil becomes sparse and its values are relatively smaller with the anode spacing increasing, electric field strength of cement-soil is more intensive and its distribution is more uniform and also its values is relatively larger with the decreasing of cathode spacing.
Characteristic Analysis of Rainfall Variation in Zhuzhaoxin River Basin
Authors: Guo Xiao Na , Yu Cui Song , Zheng Cong Qi , Liu Lin Lin , Song Mei Hua
Published: August 2013

Characteristic analysis of rainfall variation can offer technical support to flood prevention. Based on annual precipitation data of eleven major stations in Zhuzhaoxin River Basin from 1964 to 2008, Kendall method was applied to analyze the evolution tendency. Moving t-test and orderly clustering analysis method were discussed with sudden change points. Then spectrum density graph of variance was used to analyze precipitation variation period. The result showed that the variation of rainfall was obvious; the sudden change points occurred in 1976, 1986 and 2002; Precipitation variation periods were three years and seven years.
The Study of Failure Status and Treatment Methods of Open-Mining Rock Slope in Chongqing
Authors: Zhao Zhong Guo , Zhao Pei Ling , Wu Xiao Long , Xu Chun Lei
Published: August 2013

Open-mining forms high steep rock slope, slope stability is affected by geological environment, structure, stratum, lithology, hydro-geology, rock structure, structural plane appearance, slope azimuth with spatial combination relations. After mining the bared slope with weathering, due to heavy rainfall, earthquake and other factors causes secondary disasters and serious impact on people's life and property safety. This paper is based on a comprehensive investigation, statistic and classification of the status quo and failure patterns of the rock slope and treatment method is simulated and analyzed, pros and cons of various treatment methods were compared, to provide the decision-making reference for similar mines management, and basis of theory and practice , to build green mines and sustainable environment.
Numerical Analysis on Minimal Safe Distance between Two Opposite Excavation Faces of Deep-Buried Tunnel
Authors: Chen Wen Tao , Huan Yi , Fan Peng Xian
Published: August 2013

When the distance between two opposite excavation face is too small, the explosive load of one excavation face may causes rock failure of the other excavation face and result in engineering accidents. In this paper, the dynamic response of rock pillar between two opposite excavation faces during one explosive excavation cycle is investigated. An aftereffect function is adopted to reflect the viscoelastic properties of deep rock mass, and the explicit difference scheme of stress field is derived and then implemented by Matlab programs. The transient stress field of rock pillar is computed by coupling the initial stress field and the explosive waves. The analogies between the minimal safe distance and those influence factors such as explosive excavation load, rock mechanical properties, in-situ stresses, are fulfilled by this method. The back analysis results of a real case indicate that the results of presented method agree well with the actual situation.
Finite Element Analysis of Creep Induced Volume Shrinkage of Salt Caverns
Authors: Zhang Ming , Zhang Shao Xin , Yang Qiang
Published: August 2013

Salt rock is now being used widely as storage vault of oil and gas. However, the rheological properties of salt rock have significant influence on the stability of salt caverns and, in particular, induce the reduction of storage volumes. Therefore, the classical Nishihara model is used to describe the rheology of salt rock and incorporated into the finite element simulation firstly. Then the volume shrinkage is calculated for two typical simplified models with single cavern and double caverns. The results show that the storage volume of salt cavern decreases with the internal pressure and increases with service time for either single-cavern model or double-cavern model, which remains unchanged though the volume shrinkage of one cavern is influenced by others.
Study and Application of PBA Tunneling Technology in Shenyang Metro
Authors: Zhu Zhan Guo , Zhao Wen , Tan Xiao Bing , Xie Xin
Published: August 2013

The construction procedure of subsurface excavation method is very complex. In order to obtain the regular pattern that the construction process of pile hole may influence the ground surface subsidence, the author use Lizheng software to analysis the construction parameter of excavation, installation and removal of the support, back building etc. Using the finite element analysis method, the author simulate the surface subsidence. Comparing the simulation results with the measured data, the author get the regular patter of surface subsidence and the envelope diagram of Internal force and displacement of the retaining pile.
Computational Fluid Dynamics Simulation of Ventilation Effect of a Large Cross-Section Cable Tunnel
Authors: Chen Jun Sheng , Liu Shu Zhuo , Fang Ying Guang , Mo Hai Hong
Published: August 2013

The finite element software ADINA was employed in this paper to study the ventilation effect of a large cross-section cable tunnel by using a computational fluid dynamics method. The temperature and ventilation zoning inside a cable tunnel were determined according to the characteristics of the large cross-section cable tunnel. With the ambient tunnel characteristics and tunnel cross-section layout being taken into consideration, a three-dimensional model for large cross-section cable tunnels was established; the computations indicate that the main influential factors of ventilation effect of large cross-section cable tunnels are intake airflow rate, intake air temperature, exhaust airflow rate, ventilation duration, tunnel length, fire door layout, and so on. The average air velocity in the tunnel was about 60 % of the intake airflow rate. The intake air temperature has much impact on tunnel temperature distribution within a range of 30 m away from the tunnel origin, as shown by a significant cooling effect when intake air temperature falls; whereas the intake air temperature has less impact on tunnel temperature distribution beyond 30 m from the tunnel origin.
Model Test Study on a Large-Section Cable Tunnel
Authors: Chen Jun Sheng , Liu Shu Zhuo , Gu Ren Guo , Fang Ying Guang , Mo Hai Hong
Published: August 2013

The profile layout rationality and internal stress structure of a large-section cable tunnel and a cable-laying scheme at splicing locations were studied through full-scale model test. The full scale shield tunnel which the diameter was 6m was built on the ground. The model tests test the displacement of cable bearers, the coupling area between horizontal beam and steel ring, the coupling area between horizontal beam and steel pillar, edge beam and center beam under design loads, and the safety and reliability of an arc steel framing system that supports the cable load inside the cable tunnel during the operation stage were demonstrated. The cable-laying schemes for the cross section and straight-through-type and T-type couplings of a large-section cable tunnel were optimized through experiment on actually laid-out cables. For the section layout of a large-section cable tunnel, it is believed that the double-deck scheme prevails over the single-deck scheme, and such a cable-splicing scheme can meet the cable-laying requirement.
Discussion for Displacement Control Criteria of Soft Rock Tunnel in the Seismic Area
Authors: Xu Jin Hua , He Chuan , Zhou Yi , Wu Hai Bin
Published: August 2013

This paper studies on a certain highway project which passes through Longmen Shan fault zone, the one triggers 5.12 Wenchuan earthquakes directly. The region where the project resides is characterized by high percentage of soft rock mass, in particular the phyllite. Series of landslide have hitherto happened due to the instability of mountains along the highway which was caused by the great earthquake. Besides, since the phyllite-dominated rock was low-strength and easily soften by water, engineering disasters such as cave-in and large deformation of surrounding rock occurred frequently during the construction of tunnels located along the highway. The existing deformation control criteria fail gradually to fill the requirements of safe tunnelling. The author analyzed monitoring data from different tunnels with different cross-section types and different surrounding rock conditions, referred to relevant norms and eventually proposes new deformation control criteria based on allowable deformation and deformation rate.
Study on Influence Factors of Underground Joint Rock Cavern Displacement
Authors: Wang Zhen , Han Chun
Published: August 2013

The safety response of joint rock underground tunnels is one of the many problems that draw the attention of geology specialists and scholars. Adopting two dimensional discrete element method, a numerical model of joint rock underground cavern is established to study its stability. The buried depth and the lateral pressure coefficient are considered respectively. The result shows: when the lateral pressure coefficient is identical, the depth is bigger the displacement is more bigger, and the displacement is strong influenced by the buried depth when the lateral pressure coefficient is big; In the same depth the tunnel is buried, the tunnel rocks displacement is slightly influenced by the lateral pressure coefficient when it is small, but the influence is seriously as the lateral pressure coefficient is big. The simulation in the context can be used to provide guide for joint rock tunnel excavation and supporting.
Study on Stability of Surrounding Rock in Shallow Tunnel under Unsymmetrical Pressure
Authors: Xu Su Chao , Liu T. Y. , Jin C.Y.
Published: August 2013

Both of the stress field and deformation are unsymmetrical for shallow tunnel under unsymmetrical pressure and geological disaster such as collapse is easily to take place. This brings about troubling problems to both design and construction. In this paper, a case of Hongshigou tunnel is studied. Aiming at dealing with the problem of low buried and unsymmetrical pressure situation of tunnel entrance, a series of numerical studies has been done based on Flac3D, after analyzing the characterization of stress field, displacement field and plastic zones, conclusions are gained as follows:1)
2)
These conclusions can provide beneficial reference to design and construction for tunnel engineering.
Application of Horizontal Jet Grouting in Qingdao Tunnel Construction
Authors: Zhang Jin , Liu Tao , Jiang Zhi Wei
Published: August 2013

With the background of Qingdao Baoer~Hexi subway station in Water-rich Sand Stratum, research the application of horizontal jet grouting in soils underlain by rock. Introduce the difficulties in engineering and the optimization process in horizontal jet grouting. In order to understand its reinforcement effect, samples to test the point of load and compressive strength, at the same time, analyzes the impact of stratum settlement based on the monitoring data. Monitoring results show that horizontal jet grouting has great effects in control the settlement. The research results would provide guidance for the subsequent construction.
Study on the Information Processing Technology of Deformation Monitoring Data in the Underground Engineering
Authors: Wu Ke , Zhang Ke , Wang Cheng Jun , Zhao Chuang
Published: August 2013

The deformation monitoring of surrounding rock and data processing in tunnel is the foundation and safety technical support of underground engineering information control and management. However, due to the special environment in the underground engineering construction, acquiring the deformation information of surrounding rock accurately and fast to assess the stability of surrounding rock is becoming one of the bottleneck problems for underground construction project information to be solved. According to the underground engineering projects, Based on the dynamic monitoring data processing and analysis, a set of underground engineering construction monitoring measurement data processing system is established, which can meet the acquisition of the monitoring measurement data, the arrangement of the measured data, data analysis and feedback, the monitoring data regression analysis.
Mechanism of Water Inflow of Subsea Tunnel Induced by Blasting Excavation
Authors: Liu Yong Sheng , Peng Jian Guo , Zhang Jing Hua , Fu Li Xin
Published: August 2013

Water inflow was the main damage during blasting excavation of subsea tunnel, disturbance due to blasting could also induce water inflow. Based on the blasting mechanism of water-bearing fractured rock-mass, stress state and breaking-down process of the fracture was analyzed, which was affected by dynamic stress field (blasting effect) and static stress field (water and in-situ stress). With the affect of overlapping dynamic and static stress field, the calculation formula of the critical inner water pressure in water inflow was presented. At last, using these formulas, critic water press and radial extent were calculated of water-bearing fractured rock-mass in Xiamen subsea tunnel.
Numerical Experiments of Drilling Pressure Relief Preventing Roadway Rock Burst
Authors: Wen Yan Liang , Zhang Guo Jian , Zhang Zhi Qiang
Published: August 2013

Based on rock burst mechanism and the present research situation of control technique, pressure relief process of drilling to rock burst roadway is modeled by numerical simulation software, the contrast and analysis of stress field of surrounding rock are put up with and without pressure relief. The results of the calculation indicate that after drilling high stress area on the both sides of the roadway reduces obviously, but stress peak increases and its position is not converted into the deep areas evidently. It is the energy of the high stress area that makes the rock mass between the drillings failure, which achieves the purpose of pressure relief. Drilling diameter and space between drillings are main factors influencing pressure relief effect. The major the drilling diameter and the smaller the space between boreholes, the more complete the rock mass between the drillings failure and the better the pressure relief effect.
Comparison and Analysis of Influence of Soil Deformation on the Speeds of Execution for Deep Foundation Pits
Authors: Liu Li , Zhang Hong Ru , Zhang Rui Yu
Published: August 2013

The excavation of deep foundation pit by numerical simulation is researched in this paper. Different locations of soil are selected to be as test points. Under two velocities, the law of total displacements that reflect the test points in the same locations is discussed. The variation tendency of the pore pressure under the rapid construction and tendency of the volume change under the normal construction are compared. The soil is divided to three parts in numerical simulation: the side, the bottom I and the bottom II of the foundation. The numerical results are as follows: the total displacement of the rapid construction is double for ones of the normal construction, which is on the side and the bottom I of deep foundation pit. Under the different drainage conditions, the soil on the side of deep excavation experiences the dilatancy, and then the shear-contraction, and then the dilatancy; the soil on the bottom II of deep excavation experiences the dilatancy and then the shear-contraction. The soil on the bottom I experiences the dilatancy under the normal construction; but it experiences the dilatancy and then the shear-contraction under the rapid construction.
Stability Study of a Pumped Storage Power Station's Underground Powerhouse
Authors: Huang Hui , Ren Guang Ming
Published: August 2013

In this paper, we use ANSYS finite element software to establish calculation model of the underground powerhouse and FLAC3D to calculate the model in different excavation stages. The purpose of calculation is to predict the surrounding rock displacement after excavation for the reference and evaluation of surrounding rock anchoring and rock mass strength on the basis of the computed result of primary stress and displacement.
Evaluation of Supporting Structure Stability on New Fault of Xuefengshan Tunnel Zk97+830
Authors: Sun Hou Chao
Published: August 2013

For Xuefengshan tunnel, supporting stability in the course of tunneling is analysed by use of changed parameters of construction and design, which is based on construction simulation of left tunnel in the fault. It was shown that tunnel structure can keep stability after advanced little pipe injection grouting is used and supporting parameters and excavation model are changed. It can provide scientific evidence for directing construction and ameliorating supporting parameters, and it can reduce loss which is resulted by heavy collapse because of incorrect support.
Dynamic Response Analysis of Xi'an Bell Tower Timber Structure under the Metro-Vibration Load of Line 6
Authors: Zhao Teng Fei , Meng Zhao Bo , Jin Jie , Li Xi Feng
Published: August 2013

Taking Xian Bell Tower and metro line 6 as research background, at first, according to the theory of Euler-Bernoulli beam in Winkler foundation, the analysis model of train-track-foundation system was established, and then, time-history curve of metro-induced loading acts on tunnel structure is obtained by using Matlab software. Two-dimensional finite element model of the structure-soil-tunnel interaction model was established using software Ansys,. Taken loading time delay into consideration for the first time, dynamic response law of the bell tower under the metro-vibration loading is obtained. Finally, the impact of metro line 6 on Xian Bell Tower was evaluated according to the Technical specification for protection of historic buildings against man-made vibration. Xi'an Bell Tower timber structure is safe when two trains running of the line 6.
Dynamic Response Analysis of Xi'an Bell Tower Timber Structure under the Metro-Vibration Loading of Line 2 and 6
Authors: Meng Zhao Bo , Zhao Teng Fei , Jin Jie , Li Xi Feng
Published: August 2013

The effects of metro line 2 and line 6 on Xi'an Bell Tower was studied by numerical analysis in this paper. At first, according to the theory of Euler-Bernoulli beam in Winkler foundation, the analysis model of train-track-foundation system was established, and then, time-history curve of metro-induced loading acts on tunnel structure is obtained by using Matlab produce platform. Secondly, two-dimensional finite element model of the structure-soil-tunnel interaction model was established using ANSYS. Finally, the impact of metro line 2 and 6 and ground transportation on Xi’an Bell Tower was evaluated according to the Technical specification for protection of historic buildings against man-made vibration. The construction of Metro Line 2 and Line 6 will affect the safety of Xi'an Bell Tower.
The Reliability Theory Based Expert System Research for Subway Construction Safety Risk Identification
Authors: Wu Xian Guo , Liu Hui Tao , Zhang Li Mao , Ding Bao Jun , Zhai Hai Zhou , Li Xi
Published: August 2013

According to the existence of uncertainty in the subway risk identification, introduced rule-based expert system technology, integrated expertise into the knowledge base, automatically identified construction parameters based on CAD drawings, discussed and designed automatic subway security risk identification expert system based on confidence factor theory. And taken underflow sand pit in subway station construction as an example, elaborated the key issues in the knowledge base construction in details, such as risk mechanism analysis, fact base structuring and rule base structuring. And proposed to combine the contribution (C(eij)) with fact credibility ( F(eij)) to confirm the evidence credibility CF(eij) =C(eij) × F(eij), solving the credibility assignment conflict when the fact of certainty and uncertainty existed simultaneously; Selected the threshold of risk conclusions credibility in representative conditions as the sub-boundary for risk potential classification, avoiding the risk omission problem. In this way, the application of expert intelligent decision technology was broadened in subway construction.
The Current Researches on the Piston Effect in Subway Station
Authors: Fan Li , Pan Song , Chen Chao , Su Jia Le , Wang Xin Ru
Published: August 2013

More and more scholars have attached importance to the piston effect, which seriously impact the metro environment. In this paper, after referring the present researches on the piston effect domestically and oversea, the author studied their methods and results and then summed up the disadvantages, for the further exploration.
Dynamic Compressive Test and Rate-Dependent Constitutive Model of Microconcrete
Authors: Zhang Hao , Li Hong Nan , Li Min , Tong Jia Xin
Published: August 2013

The dynamic compressive tests of microconcrete were carried out under the strain rate of seismic action. Based on test results, the rate-dependent compressive constitutive model of microconcrete was proposed. In order to verify the accuracy and efficiency of the proposed constitutive model, the dynamic compressive tests of microconcrete were simulated by finite element software ABAQUS. Results show that the dynamic compressive strength and elastic modulus of microconcrete increase with the increasing strain rate. There was no obvious change on strain at peak stress. The compressive stress-strain curves of microconcrete were similar to concrete. The results of numerical simulation approximately agree with test results. The proposed constitutive model can simulate the dynamic compressive property of microconcrete very well.