bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Gob Water Mining Hydraulic Conductivity of Fractured Zone Height Measurement in Fujian
Authors: Wu Chao Fan , Liu Ming Song , Wen Xing Lin
Published: September 2011

Fujian Province is one of Coal shortage for the southern provinces, under the premise to ensure safety of existing and the nowadays conditions of mining as much as possible recovery of coal resources under the old empty water. Uncle YongDing County, Fujian Province Coal mining under the old empty water, for example, to carry out joint working face with a high degree of water flowing fractured measured. Because the field complex geological conditions, the use of empirical formula and numerical simulation method to calculate the upper mining limit, and greater access to the actual situation. Only through in-situ measurement, to obtain specific geological mining conditions of the mine under the true information in order to obtain the actual situation of the mine found the correct data. To this end, this small coal mines in Fujian Province in the first the new technology that upward hole with a multi-stage water underground observation method was used to observe a high degree of fracture of Water, through in-situ construction and arrangement of holes and cracks under the conduction of water with a high degree of observational data analysis and results showed that after two coal face showed continuity with the overlying rock fracture characteristics, top boundary height 43.4m, 3.5m thickness calculated in accordance with mining, mining split ratio of 12.40.
Seepage Analysis and Construction Practice of Anchorage Circular Foundation Excavation in Long-Span Suspension Bridge
Authors: Ling Xiao , Wang Rong Hui
Published: September 2011

Abstract：On the basis of preliminary exploration, complement exploration is executed to obtain excavation seepage analysis detail parameters. According to the three-dimension finite difference method and regulating calculation method, the excavation seepage analysis of anchorage circular foundation at Huangpu bridge south and the influence of different depth rock-socketed on foundation seepage are discussed. With the experience in similar projects at home and abroad, the depth of diaphragm wall embedded in weak weathered rock is not less than 3 meters, grouting curtain wall consists of 10 meters, and the waterproof curtain outside the foundation is canceled from preliminary design. The stress, strain and water level are monitored during the excavation process, and the deformation of the supporting structure is within the control. The structure is under reasonable force and the sealing effect is obvious when the foundation is excavated. Construction practice shows that the excavation seepage analysis of anchorage circular foundation at Huangpu bridge south are consistent with engineering practice.
Study on the Effective Reinforcement Depth of Dynamic Consolidation
Authors: Song Xiu Guang , Yao Kai , Wu Qing Dong , Liu Ji Shan
Published: September 2011

The effective reinforcement depth was the main design basis of dynamic consolidation. The concept and affecting factors of the effective reinforcement depth were analyzed in the paper. The evaluating standards and determining methods were also summarized. The effective reinforcement depth could be determined from the field test and the in-situ test index. Three kinds of methods could be used to determine the effective reinforcement depth: field testing method, numerical simulation method and formula method.
An Experimental Study on the Mechanical Properties of Soils of the Landslide Induced by Rainfall
Authors: Hao Dong Heng , Qi Jian Feng , Wang Bin , Zhao Shu Qin
Published: September 2011

Geotechnical tests are performed to study the strain-stress behavior and mechanical parameters by using the automatic KTG triaxial shear apparatus. This study shows that the strain softening phenomenon emerges after the peak values of strain-stress relations appear for the sliding-body soils, and that the strain-stress relations are in the sate of strain hardening all the time for the sliding-zone soils although the water content keeps sameness. The variation laws of cohesion and internal friction angle with water content are respectively consistent with an exponential function and linear relation.
Deformation of Reservior Landslide during Reservoir Water Fluctuation
Authors: Mao Wei , Yan E Chuan , Song Kun , Zhang Ting Ting
Published: September 2011

On the base of the obtained materials and considering the factors of composition features, dynamic mechanism and deformation-motion characteristics, the three-dimension numerical simulation model is generated. And the parameters of Young module, passion ratio and shear strength are obtained. Then the calculation conditions are extracted from the combination of the inducible factors and the displacement features. After that, the deformation failure are simulated by the FLAC3D code, and the results are compared to the monitoring data. The results indicate that the influence of the water impoundment on the stability of the landslide is small, the water descending is large. For the front part monitoring points, the amounts and the curve shapes of the numerical calculation results are accord with the practical ones, but for the monitoring point in back there are only the similarities in the curve shapes, and the amounts are a little smaller.
Development and Implement of a New Shear Creep Apparatus
Authors: Lin Xiao Yan , Li Tong Lu
Published: September 2011

The conventional shear creep apparatus uses lever to amplify the load, which has a serious limitations in practical use. First, the round and small shearing box can easily form an obvious stress concentration in the margin area. In addition, tilting of the lever can give an unreal vertical load in loading process. Aiming to solve the shortages of conventional apparatus, a new type of shear creep apparatus is introduced in this paper, whose loading system apply the pulley block, and shear box is changed from the round with the area of 30cm2 into the present square one with 10×10cm2. The new shear creep apparatus has more advantage compared with the conventional, and is more satisfactory to the need of test.
Wind Load Analysis on Adherent Billboard Considering the Turbulent Wind
Authors: Gao Yong Tao , Hu Xiao
Published: September 2011

Due to the applicable installation height, small mass, flexible characteristic, and small damp, the adherent billboard could easily result in vibration with the wind effect. The main factor is the turbulence among the cause effects. Combining the structural dynamic theory, and considering the characteristic of the adherent billboard, a wind effect calculation formula is set up considering the turbulent wind that is resulted by the 1st vibration type. Hope to provide some reference for similar structure designs.
Physical Model Test and Forecasting Analysis of Boji Stone Landslides
Authors: Gao Yong Tao , Hu Xiao
Published: September 2011

In the interest of forecasting and alarming system of rainfall landslides, the Boji stones landslide of Three Gorges is taken into researching. On basis of the model, its epitomized model is formed to analyze the landslide mechanism and damage model by taking them into consideration: water-level fluctuation in reservoir, rainfall intensity, rainfall capacity and soil mass mechanical property, and decide current stability, predict its tendency and potential risks through applying the monitoring data and quantitative analysis. The research indicates that Boji stone landslide in flowing reservoir is in stability without any extra dynamic
Simulation of the Seepage Field in the Danjiangkou Reservoir Area
Authors: Xie Xiang Dong , Xu Li Hua
Published: September 2011

According to the geological conditions of the Danjiangkou reservoir, the computational model was set up considering fracture zones and the changing along the depth of mechanical properties of rock. Adopting this model, the seepage field of the reservoir area was simulated for long time, which shows that: 1) The medium and small earthquakes in the reservoir area were induced mainly by reservoir water seepage since phaseⅠimpoundment; 2) A series of medium earthquake would be induced in the fracture zones of reservoir bottom and around the reservoir bank in the depth of 5km about in a month of phaseⅡ impoundment; 3) A series of small earthquakes would be induced in the fracture zones in the depth of 12km to 16km at the same period.
Adjustments of Ground Motion Input Based on Ground Micro Tremor Test to Determine Ground Dynamic Characteristics and its Anisotropy
Authors: Zuo Jun
Published: September 2011

According to the seismic anisotropy theory and the test observation, this paper puts forward the conception of the ground micro tremor anisotropy, and researches the method of the micro tremor test analysis about the anisotropy of the ground dynamic characteristics. Given the anisotropic characteristics of the ground motion, it analyzes the influence of the ground motion anisotropy on the seismic dynamic response of the structure, and the existent problems about the selection and adjustment of the existing seismic time history in the structure analysis process. Finally, this paper puts forward the new selection and adjustment solution of ground motion input based on the ground micro tremor test to determine the ground dynamic characteristics and the ground anisotropy.
Dynamic Analysis of Reticulated Shell Subjected to Earthquake Excitation
Authors: Yang Zhong , Xu Yun , Zhao Bing , Chen Xu Jun
Published: September 2011

An optimum reticulated shell structure is selected and its dynamic properties are analyzed. In this paper analyses the dynamic feature and gains the elementary parameters from the analysis of free vibration. The frequencies and modes are compared by two finite element methods. The paper analyzes the dynamic responses of the reticulated shell structure subjected to two-dimensional and three-dimensional earthquake waves respectively. Simultaneously analyses the linear，geometric nonlinear and both geometric and material nonlinear dynamic responses in two situations. The nodal displacements and stresses of members are compared and analyzed. The characteristics of elastoplastic seismic responses of the structure are revealed and the basic rules are obtained.
Discriminant Condition of Influencing Dynamic Response for Structure-Equipment System
Authors: Han Fang , Zhong Dong Wang , Mo Ji Yun
Published: September 2011

In structure-equipment system, there are complex dynamic interactions between structures and equipments. A fast discriminant condition whether the interaction will increase or decrease dynamic response of the structure is achieved in this paper. When the load frequency lies between the basic frequencies of the combined system, it decreases the absolute response of the structure and vice versa. In engineering project, the seismic load can be expanded based on ground characteristic frequency by Fourier transform, so our conclusion can be extended to seismic design for combined systems. Finite element method simulation for a chemical workshop further verifies the discriminant condition.
The Non-Stationary Characteristic Study of Multidimensional Ground Motion by HHT Method: A Case Study from the Chi-Chi Earthquake
Authors: Chen Hui Guo , Li Ying Min , Shi Shao Qing
Published: September 2011

Based on HHT method, the influences of site conditions and epicenter distance on non-stationarity of multidimensional ground motion were studied. Additionally, preliminary statistics were carried out on frequency characteristics of multidimensional ground motion under different site conditions. The analysis results showed that HHT method was more accurate in a quantitative description of frequency-domain non-stationarity of ground motion than zero-crossing rate method, and also can reflected the non-stationarity of multidimensional ground motion better.
Characteristics of Gravelly Soil Liquefaction in Wenchuan Earthquake
Authors: Hou Long Qing , Li Ai Fei , Qiu Zhi Ming
Published: September 2011

Liquefaction of sand soil such as silty sand was quite popular in earthquake. Gravel liquefaction, by contrast, was seldom. Soil liquefaction was popular in Chengdu Plain in Wenchuan Earthquake and there was ejeched gravel in several sites. Through drilling and tests for typical liquefied sites, the study on distribution of layers, compactedness , shear wave velocity, particle size distribution had been performed. The results shows: (a) Soil distribution is similar in 2 typical liquefied sites which are located in different location and different seismic intensity regions. Gravelly sand was the only cohesiveless soil which is possible to be liquefied,so gravel liquefaction was true; (b)The liquefied gravel was the characteristics of shallow, loose , low shear wave velosity and. the Holocene sediment. (c) Particle graduation of liquefied gravelly sand was poor and there was a short of soil fraction.
A Study of Power Spectral Density Models of Earthquake Ground Motion
Authors: Liu Fu Jun , Zhu Yu Hua , Ma Xiao Hui
Published: September 2011

In this paper, a modified random process model of earthquake ground motion based on the model proposed by JinPing Ou is presented. The parameters in the model except the factor S0are determined by using the least square method and the power spectral densities of 361 earthquake records. Then the method for determining the parameter S0is proposed. The good performance of the proposed model in this paper in modeling the earthquake ground motion on firm ground is demonstrated by comparing it with other random process models.
Gas Drilling Cuttings Breaking on Return
Authors: Zhu Zhong Xi , Liu Gong Hui , Li Jun , Li Meng Bo
Published: September 2011

More cuttings producing in higher penetration rate of gas drilling are usually in the larger non-uniform size at the bottom and in the smaller uniform size back to the wellhead. It is indicating that cuttings in the well should be appeared in the successive breaking in the process of upward migration. According to the particle broken theories, the successive breaking phenomenon were analyzed, and given the calculating method for the probability of secondary impact crushing, and applied the breaking process matrix and the particle size distribution function to the cuttings migration crushing in the whole wellbore. The calculating results show that the cuttings in the wellbore are broken by the uneven size volumetric fracture progressively turned into the surface fracture of the uniform process, and ultimately stabilized the small size distribution.
Damping Value for Seismic Response Analysis of Long-Span Bridges
Authors: Yu Ling Ling
Published: September 2011

The current problems on damping in seismic response analysis of bridges is presented. The Rayleigh damping theory is simply introduced in this paper. Taking the Longtan River Bridge for instance, the finite element model of Longtan River Bridge (left line) is established. Then, the dynamic properties of the bridge is analyzed. Based on this, the Rayleigh damping constants and in an ANSYS dynamic analysis are obtained.
Collision Response of Bridge Girder with Shearkeys Subjected to Seismic Loads
Authors: Wang Bo , Liu Yu Xiang
Published: September 2011

In return for the collision response of bridge girder with shearkey subjected to seismic loads, a simplified dynamic model has been built by using the finite element analysis program Ansys/Ls-dyna. Based on the analysis of calculation results, the motion feature of this model is unfolded. Also, the stress response and characteristic at the bottom of shearkeys are analyzed, which are the most important parameters reflecting the cracking of shearkeys. Furthermore, the deformation of rubber bearing is elaborated to illustrate the collision of bridge girder with shearkeys. Finally, other key properties about the bridge girder of this collision system are addressed.
Spatial Coherency Function of Seismic Ground Motion Based on UPSAR Records
Authors: Yu Rui Fang , Yuan Mei Qiao , Yu Yan Xiang
Published: September 2011

The U.S. Geological Survey Parkfield Dense Seismograph Array (UPSAR) successfully recorded strong motions during 2003 San Simeon earthquake (M 6.5) and 2004 Parkfield earthquake (M 6.0). Because the array covers a very small area (0.45km2), these data offer some interesting insights into spatial variations of seismic ground motions that suits for engineering scale. In this research, we study the spatial coherency function of seismic ground motion in the horizontal and vertical directions by digital signal processing. The results show that when the circular frequency is smaller than , the degressive trend of the coherency function becomes significant with the separation distance elongation, while the data deviation of the coherency function becomes larger with the frequency rise, which shows no obvious rules. In addition, based on the strong-motion data, a suitable spatial coherency model of ground motion is selected through comparing existing model functions, and the appropriate recommendations for improvement is put forward. Finally, according to different frequency range, the fitting parameters of the spatial coherency function of ground motion are obtained through numerical simulation. The spatial coherency function proposed in this paper is practical in simulation of ground motion field.
General Layout and Key Construction Technologies of Large Scale Centrifugal Shakers
Authors: Wang Yong Zhi , Yuan Xiao Ming , Sun Rui
Published: September 2011

A large scale centrifugal shaker is the most effective testing facility for dynamic problems in geotechnical earthquake engineering. There are only two worldwide nowadays, whereas, no one has been established in China. As the most advanced testing facility, almost every aspect in the construction of a large scale centrifugal shaker encounters new challenges. Meanwhile, the facility layout and construction design face many new difficulties. In this paper, the general layout of laboratory and some relevant key technologies in construction are investigated and the scheme of facility general layout is proposed. The composition and variation of total power of centrifuges is analyzed, simultaneously the advantages and limitations of different cooling systems in the operation hall are compared. Also basic requirements and difficulties of foundation design are discussed, which can provide reference and guidance to construction of large scale centrifugal shakers.
Main Transportation System Earthquake Damages due to Slope Failure and near Fault Effection in 8.0 Wenchuan Earthquake
Authors: Tang Ai Ping , Wang Lian Fa , Wen Ai Hua
Published: September 2011

A Ms=8.0 earthquake striked the most of the China on May 12th, 2008, and brought about near 90,000 deaths and about 700 billion dollars of direct economic losses. This earthquake impacted all kind of transportation system including highway, railway, airline and water carriage systems in a huge area. This paper provides many records of observed damage to transportation system by site investigation. The seismic performances related to transportation system in meizoseismal zonation were described in details in this paper. Occurring in a mountainous region, this earthquake severely damaged the transportation system because of strong earthquake motion, near the active faults, trigged landslides and debris, rock and soil collapses, and large ground deformation. Transportation system performance degradation was due to not only physical damages of equipments and buildings, but also the shortage of the electric powers and supporting from other lifeline systems. some statitical laws among transportation system , slope failure and fault distance, and some valuable measures for resisting strong earthquake motion, secondary earthquake-induced geological disaster and lessons learned for damage prevention and system recovery to lifeline system were also discussed in this paper.
Reduced-Scale Experiments on Smoke Extraction Capability in Tunnel Fire
Authors: Xu Lin , Zhang Xue Qing , Cui Yong Zhang
Published: September 2011

In case of tunnel fire at congest traffic, central smoke extraction by controlling the longitudinal flow velocity can confine and extract the fire-induced smoke in a short time, and retain the natural stratification as well as possible for obvious reason of safety. With respect to three vents located on both sides of the fire in an asymmetrical arrangement, a series of experimental tests are carried out in a 1/14 reduced scale model tunnel. For the experimental simulations, fire induced smoke is simulated by a heated air release using the model proposed by Mégret et al. Detailed temperature distributions in the tunnel have been carried out. According to the test results, it is difficult to give consideration to the smoke control both upstream and downstream the fire. At critical ventilation, until the exhaust rate Ge is more than 519m3/s, air temperature in the respiratory region can decrease to 322K for people survival.
In Situ Testing of the Vibration Isolation Effect of the Vibration Isolating Trench
Authors: Mao Kun Ming , Chen Guo Xing , Zhang Yang , Hong Xiao Xing , Ruan Bin
Published: September 2011

One trench for agricultural irrigation next to the Hu-Ning Intercity Railway viaduct section were tested and analyzed in order to obtain the effect of ground vibration isolation when CRH trains run on. The result shows that with the decreasing train speed, the peak value of ground vibration velocity decreases and the main frequency of ground vibration heightens. Trench has lowpass filtering effect on ground surface vibration. The slower the train speed, the better the effect of isolation, but the phenomenon that ground surface vibration increases before trench is more obvious. When the length of trench is much longer than the length of train, the number of carriages has little effect on vibration isolation effect of the trench. When railways are built, consulting with nearby residents and department of agriculture, and the trench’s length, depth, breadth and the distance to railway should be designed reasonably. And then the trench in addition to meet need of irrigation, but also has very good effect on vibration isolation.
Large Deformation Prediction and Feedback for a Reservoir Slope near a Large-Scale Hydropower Station in the Upstream of Yellow River
Authors: Peng Jing , Fu Wen Xi
Published: September 2011

This paper analyzes the deformation features and possible “true” displacements of a reservoir slope near the Laxiwa hydropower station in the upstream of Yellow River using the neural network. The error correction is also discussed for the results calculated by the neural network. The displacement prediction and feedback analyses of the reservoir slope in this paper show that the slope deformation and failure has occurred before water impoundment.
Duncan-Chang Nonlinear Elastic Model Considered Loess Structure
Authors: Chen Chang Lu , Shao Sheng Jun , Ma Lin
Published: September 2011

Duncan-Chang nonlinear model has been modified and applied to the structural loess calculation. Based on structural studies and conventional triaxial tests, this paper has analyzed the mechanical properties of intact loess and the relationship between the stress ratio structural parameters and the strain, then the expression of generalized shear strain and stress ratio structural parameters are given to facilitate the engineering applications. On this basis, the stress-strain curve of intact loess was corrected by the use of the stress ratio structural parameters. The form of the intact loess stress-strain curves which have been revised has changed hardening from the softening or weak softening. The results show that the modified stress-strain curves of intact loess can apply Duncan- Chang nonlinear model to calculate and the model parameters are reasonable and effective. This method provides Duncan-Chang nonlinear model which is widely used in engineering with a new ways and means in intact structural loess application.
Research on Blasting Control Technology for Blast in Shallow Tunnel Crossing Existing Buildings
Authors: Wang Yun Long , Tan Zhong Sheng , Chi Yong Li
Published: September 2011

Based on the JIAOZHOU bay subsea tunnel in QINGDAO city, with the experimental equation of charge establishment and coherent code, the blasting control technology for blast in shallow tunnel crossing existing buildings of JIAOZHOU bay subsea tunnel is studied. According to a large number of tunnel construction field test data while blasting and the method of regression Analysis, the vibration wave propagation and the calculation parameters of charge quantity is obtained, then calculating the maximum allowable amount of primary explosive segment. Finally the blasting program is optimized. Based on the above methods，house maximum blasting velocity is controlled under 2cm /s . According to the test results of different floors of the building blasting vibration velocity, the velocity of the first floor is greater than the velocity on each floor, so, the velocity of the first floor is recommended to be the control velocity while the maximum charge quantity is calculated. This study is not only useful to ensure the building’s stabilization when blasting in JIAOZHOU bay subsea tunnel but also offers the theoretical and methodological experiences to the similar engineering．
Study on the Failure Envelope of Suction Bucket Foundation under Torsion Shear Load
Authors: Wu Ke , Ma Ming Yue , Li Shu Cai
Published: September 2011

As an advanced technology in coastal and offshore engineering, wind-driven generator, the suction bucket foundation is one new offshore foundation. It is not only subjected to the long-term action of vertical load(V) induced by all weights of platform and equipment, but also is imposed by both horizontal load(H), moment(M) and torsion(T) caused by wind and wave as well as current. The judgment standard of bearing capacity behavior and practical performance of suction bucket foundation under many freedom loads have been established, which was one key of problems to appraise the stability of foundation. According to the existing results, the features of ultimate bearing capacity and failure envelopes of bucket foundation under combined loads was evaluated in the framework of the general-purpose FEM software package ABAQUS. Results indicated that the failure envelopes of bucket foundation in different loading spaces were plotted, which could be used to evaluate the stability of bucket foundation.
The Methods of Damage Localization and Assessment for Long-Span Reinforced Concrete Arch Bridge
Authors: He Guo Jing , Xie Fei , Xie Lan
Published: September 2011

The increase in axle load and speed, the worse of service environment and the deterioration of existing bridges result in various of damages in structures. In order to ensure the safety of the structure, it is essential to assess the performance of the structure. In this paper, based on the frequency changes of the damaged and undamaged structure, damage positioning indicator method was used to locate the damage of the structure. Damage assessment method (SSZD) based on modified modal strain energy method was used to assess the extent of structural damage. The results show that this method can be used to locate and assess the structural damage accurately.
The Empirical Formula Research and the Test for the Soft Clay Coupled Consolidation and Creep Character in Different Drainage Conditions
Authors: Tang Bin , Zeng Zhe , Gong Yan Xia
Published: September 2011

Abstract: Conducted a series of triaixl coupled consolidation and creep tests ,and researched the coupled consolidation and creep character for the typical soft clay in Wuhan region in different drainage conditions.The following conclusions are got from analysing the stress、strain and time relationship curves in different conditions:(1)The consolidation drainage condition is very important in the soil consolidation creep deformation.When the stress is low,the deformation amount in the consolidation undrained condition is much smaller than that in the consolidation drained condition;with the increasing of the stress,the viscoplasticity will appear,and the deformation speed in the undrained condition exceeded that in the drained condition;when the stress increases to some point,the deformation amount in the undrained condition will exceed that in the drained condition finally.(2)The consolidation creep deformation rule for the typical soft clay in Wuhan region in different drainage conditions can be expressed by empirical formula.
Analysis on Influence of Shield Tunnel Crossing under Intercity High-Speed Railway Station
Authors: Lu Sheng Rong , Gong Quan Mei , Jia Yu
Published: September 2011

Based on an engineering example of a certain shield tunnel passing through an intercity high-speed railway station which has been reinforced by pile-slab structure, this paper adopts finite element numerical simulation to study the influence of shield tunneling construction on the pile-slab reinforced structure and railway subgrade. The research result shows that the horizontal displacement and additional bending moment on both sides of bored piles are increasing in the process of shield tunneling, while those of the middle bored pile firstly increase and then decrease. The vertical displacement and axial force variation of the middle bored pile are more obvious than that on both sides of the bored piles. The settlement and additional bending moment of the reinforced concrete slab are relatively large in the center and midspan of both sides, the position of maximum settlement and negative bending moment is near the concrete slab just above the right tunnel, while the maximum positive bending moment is located in the very middle of the concrete slab. The pile-slab reinforced structure can effectively control the settlement and differential settlement of the intercity railway subgrade caused by shield tunneling, thus the intercity railway can keep normal operation.
The Pile Reinforcement Effect to the Displacement of Geotechnical Materials in the Stratified Rock Slope
Authors: Chen Ke Ping , Liu Jin Yuan , Yuan Bing Xiang
Published: September 2011

Piles have been used in geotechnical engineering to stabilize slope for many years and the methodology has been accompanied by a significant bibliography. In the past, methods of analysis of pile-reinforced slopes have often used limit equilibrium methods, where rock–pile interaction was not properly considered. Recently, with rapid development of computer techniques, numerical methods using either finite element or finite difference methods have been widely applied in slope engineering, and have been shown to offer many advantages over limit equilibrium method, such as the ability to develop the critical failure surface automatically with fewer assumptions. However, seldom studies have been done on the stratified rock slope reinforced by piles, so in the present paper, the numerical simulation software FLAC3D is adopted to model the stratified rock slope, then the reinforced effect like deformation and stress of slope are studied, to give guidance for the real practice.
3D Finite Element Simulation on During Shield Tunneling
Authors: Liu Yi , Li Ji Shun , Wang Bao Lian
Published: September 2011

Based on the comprehensive analysis on the primary components of ground movement associated with earth pressure balance (EPB) shield tunneling, a three-dimensional nonlinear finite element model for simulating EPB shield tunneling is proposed. The proposed modeling techniques are applied to simulate a tunneling project. The distributions of soil displacement on the ground surface associated with the advance-ment process of shield tunnel are analyzed. According to the comparisons of numerical results with field measurements, the proposed numerical procedure is found to be an effective approach for predicting the deformation dun to shield tunneling. The further analysis shows that the computed results of the small-strain constitutive model are more reasonable, and the small-strain mechanical behaviors of soils should be taken into account
Study on the Application of Bolt-Grout Reinforcement in the Deep Soft Rock Roadway
Authors: Dun Zhi Lin , Ren Da Shuai , Ren Lian Wei
Published: September 2011

With the increasement of mining depth, the strata behavior of the roadway is obvious. As the stress of surrounding rock increases, the bottom of the soft rock roadway becomes deformed easily compressed by its top rock and two sides rock, which leads to the occurrence of the pucking and roadway destruction. Aiming the air inlet roadway destruction phenomenon of -450th level powder magazine in Hebi Zhongtai Mining Co.Ltd, the geological condition and the mechanism of the roadway failure are analysed comprehensively, and the bolt-grout supporting method is also proposed in this paper. At last, the deformation and heaving floor are controlled effectively which is proved by the field monitoring results.
Elastic-Plastic Solution of Circular Tunnel Based on Unified Strength Theory
Authors: Ma Qing , Zhao Jun Hai , Liu Zhao
Published: September 2011

φThe circular tunnel is a common structure in civil engineering. Mohr-Coulomb strength theory has been used to analyses pressure tunnel in the field of rock engineering for many years. Because it could only solve the problems with one kind of material, the application of the theory was greatly restricted. In this paper, the formulas calculating yield range and stresses are deduced based on the proper choice of the first principal stress used in the unified strength theory according to loads and in-situ stresses. The applicability formulas is gained based on the critical pressures, which can be obtained in other situations or strength thoeries simplified by assuming the parameter value in the formula. An example is analyzed, and the yield range versus the inner pressure and stress distribution are presented. Results are compared to those based on the traditional method and significant disparity is observed. The results indicate that the coefficient b, cohesion c, friction angle φ all have significant influences on the yield range and stresses.
Analysis of Temporal-Spatial Effect for Tunnel Construction in the Fault-Rupture Zone
Authors: Li Da , Li Xiao Xu , Li Yong Sheng , Luo Zhan Fu
Published: September 2011

Based on the existing research results, this paper proposes a temporal-spatial relational expression of displacements of tunnel perimeter during tunnel excavation. Taking Guanjiao tunnel as example, using the expression, temporal-spatial effect for Guanjiao tunnel in the fault-rupture zone are analyzed and studied. Comparison of theoretical solutions with measurements has proved that temporal-spatial effect for soft rock tunnel can be reflected by the expression and these results provide reasonable proposal for the optimum time to construct the secondary lining.( the constructing time of secondary lining) and reserved deformation.
Influence of PGV on the Internal Forces of Subway Station
Authors: You Hong Bing
Published: September 2011

A hybrid simulation method is used to generate two group artificial ground motions that are compatible with the same acceleration response spectrum, same peak displacement and different peak ground velocity (PGV). The influences of PGV on the internal forces of subway station are studied. For the time histories with the same response spectrum and same peak displacement, the larger PGV of input motions may lead to the great plastic deformation of the soil, and then cause the larger internal forces for the most elements of subway station. The influence of PGV should be considered reasonably in determination of design ground motion parameters for underground structures.
The Numerical Simulation of Settlement Characteristics of Storage Tank on the Soft Soil Base
Authors: Wang Shuai , Yu Ran Gang , Zhang Xu Dong
Published: September 2011

According to analyze the settlement characteristics of storage tank foundation at water-filling preloading stage and stable loading stage based on numerical simulation, and researching the settlement characteristics of storage tank foundation. The research results show that the deformation of storage tank foundation is “tray” in shape, and the maximum settlement appears at the place 0.65D away from the center of storage tank bottom, D is the radius of storage tank. Uplift appears at the place 1.3D away from the center of oil tank bottom, and the final uplift value is 10mm.The main factor which influences the consolidation speed of storage tank foundation is permeability coefficient.
Study on the Correlation between Strength Parameters and Shear Wave Velocity of Pavement Subgrade Soil
Authors: Cheng Guo Yong , Liu Xue Juan , Qiu Rui
Published: September 2011

By using three kinds of subgrade soil and controlling dry density and moisture content，the correlation between strength parameters of pavement subgrade soil, California Bearing Ratio(CBR) and Resilience modulus E, and their shear wave velocity are studied through CBR Penetration test, lever pressure meter test and shear wave velocity test. Then the analytical models of CBR and Resilience modulus E by shear wave velocity are proposed. These models are valuable to acquire airport pavement subgrade soil parameters by nondestructive technique.
Analysis of TBM Tunnel Behavior in Jointed Rock Mass
Authors: Sun Jin Shan , Guo Hong Jun , Lu Wen Bo , Jiang Qing Hui
Published: September 2011

The factors affecting the TBM tunnel behavior in jointed rock mass is investigated. In the numerical models the concrete segment lining of TBM tunnel is concerned, which is simulated as a tube neglecting the segment joint. And the TBM tunnel construction process is simulate considering the excavation and installing of the segment linings. Some cases are analyzed with different joint orientation, joint spacing, joint strength and tunnel depth. The results show that the shape and areas of loosing zones of the tunnel are influenced by the parameters of joint sets and in-situ stress significantly, such as dip angle, spacing, strength, and the in-situ stress statement. And the stress and deformation of the tunnel lining are influenced by the parameters of joint sets and in-situ stress, too.
Deformation Analysis of Jiagar Twin-Bore Tunnel in Tibet
Authors: Chilie Jiang Cun , Song Kun , Yan Echuan , Xie Liang Fu
Published: September 2011

Twin-bore tunnel is the better and useful structure form of wide span under complex conditions, and the Jiagar Tunnel is the Twin-bore tunnel of the expressway from Lhasa City to Gonggar International Airport. In the paper, we studied the deformation characteristic of the tunnel during two construction scheme, the sequential and whole excavation, by the numerical simulation of FLAC3D code. We obtained that the key points deformation characteristic was similar, the obvious part of the x-displacement is the joint of the tunnel roof and the side wall and the y-displacement is the midpoint of the tunnel floor. And the sequential excavation is better than whole excavation.
Analysis of the Tunnel Construction and Monitoring Measurement under Complicated Geological Conditions
Authors: Gu Zhan Fei , Liu Zhi Kui , Chen Hong Chi , Wang Ya Wei
Published: September 2011

In view of certain areas of Guizhou are soft sandstone rock, where single block of rock's hardness is very low and easily crushed, complicated hydrogeology and low level of complex surrounding rock and geological conditions, geological radar prediction is used before the excavation of the tunnel, and New Austrian Tunneling Method was used in the construction. The process of construction segment had been monitored and measured, and the deformation of tunnel had been controlled. According to the situation during excavation and monitoring, the construction method was further improved. Through tracing and monitoring the tunnel construction of from zk40+430 to zk40+630 sections for two months, showed that the tunnel construction method is effective in this paper.
Influence of Anisotropic Rock on Tunnel Stability with Consideration of Fluid-Solid Coupling
Authors: Hwang Ryong Hyon , Yang Tian Hong , Sun Pei Feng
Published: September 2011

In general, rock mass is anisotropic because of presence of stratification, foliation or joints in it. In this paper we considered how the angle of anisotropy influences the stability of tunnel. By using COMSOL Multiphysics, fluid and 2D plane models are coupled to analyze stress-strain state, failure shape and water flow characteristic around tunnel for angle range from 0° to 90° with a interval of 15°. Results show that in condition of vertical force of initial stress field larger than horizontal one, failure district is maximum for θ=40° and minimum for θ=90° where the strength of horizontal direction in anisotropic rock is smaller than the vertical one. In this case failure is mainly developed in roof and bottom. When the horizontal strength of anisotropic rock is larger than the vertical, results reverse. In anisotropic rock, the more the direction of larger permeability is coincident with one of source underground water acted, the more water flows into tunnel.
Analysis of Seismic Dynamic Response of Tunnel in Karst Areas
Authors: Chen Lin Jie , Liang Bo , Wang Zhi Yong
Published: September 2011

Based on soil-structure interaction model, the seismic dynamic response of tunnel in karst areas were performed by using viscous-spring artificial boundary and time history analysis method. In combination with the Menglian tunnel engineering on the Bao-Teng Highway in Yunnan, in different sizes and sites karst caves conditions, the dynamic responses of displacement and internal force on control points of the tunnel structure were obtained. The results show that comparatively large interal forces, under the high-intensity earthquake conditions, will appear on the side wall of the tunnel which through karst areas, less ones on arch crown and inverted arch parts, and the differential displacements of arch crown reach to the maximum. When the karst caves are located in the side of the tunnel, it make the seismic dynamic response get more large, which make the surrounding rock must be strengthened treatment. The results provide useful reference for the aseismatic design of tunnel.
Aerodynamic Comfort Analysis of High-Speed Trains Passing each other at the same Speed through a Tunnel
Authors: Yan Ya Guang , Yang Qing Shan , Zhang Jian
Published: September 2011

On the basis of the three-dimensional,compressible,unsteady-state,viscous N-S Equation and k-ε turbulence model,the simulation calculation is made with the finite volume method on the aerodynamic effect of two high-speed trains passing each other at the same speed through a tunnel,simulating the pressure change,analysising regularity of the pressure,researching comfort in the train.The following conclusions have been drawn from research:The maximum of transient pressure is concerned with the meeting point,when the two high-speed trains meet in tunnel.When the length,the speed and the sealing factor of the train are same,the transient pressure is maximum with the trains meeting at the midpoint of tunnel.When the tunnel length,the speed of the train,the sealing factor and the point of meeting are same,the transient pressure of the longer train is maximum.When the sealing factor is greater than 15s,the standard of permissible pressure (1250Pa\3s) can be satisfied with all circumstances.
Calculation and Analysis of the Tunnel Lining's Thermal Stress Field under High Temperature
Authors: Li Meng , Chen Wen Hua , Jia Wei
Published: September 2011

Considering the high temperature problem, this paper details the process of the heat conduction, builds the differential equations of the heat conduction, discusses the boundary conditions. According to the differential equation of the heat conduction, determined the calculation formula of thermodynamic parameters of the heat conduction and get the calculation formula the temperature and interface between the lining and surrounding rock’s calculation formulas. Builded the model of the thermal stress field of the tunnel lining under the high temperature, compiled the calculation program, analyzed the change of the lining’s stress and the influence by the relevant parameters of lining’s stress field under the high temperature.
Two Dimensional Parametric Analysis of Time Variation Characteristics of Raft Foundation on Saturated Subsoil
Authors: Cui Chun Yi , Wang Zhong Tao , Li Xiao Fei
Published: September 2011

For further discussing time variation characteristics of raft foundation on saturated subsoil due to consolidation, parameterized numerical analyses are completed based on Biot consolidation equations by developing elasto-plastic coupled FE model in plane strain state, together with adopting Mohr-Coulomb yield criterion. Computational results show that internal force and deformation of raft foundation display obvious non-monotonic features, which is associated with dissipation of excess pore water pressure. The disequilibrium of dissipation of excess pore water pressure displays more intensive between subsoil areas near raft center and the border due to less Poission’s ratio of subsoil, which leads to more dissipation time and regulation magnitude of distribution of stress and deformation in subsoil. When subsoil is of low permeability coefficients and Poission’s ratios, the non-monotonic features become more clearly and sustain with longer term variation characteristics.
Water-Inflow Forecast of Submarine Tunnel Based on BP Neural Networks
Authors: Cai Chen , Huang Tao , Li Xun , Li Yun Zhen
Published: September 2011

The submarine tunnel water-inflow question has many kinds of factor synthesis influences, has highly the complexity and the misalignment, This article used the BP neural network algorithm to establish the submarine tunnel welling up water volume forecast model and to carry on the computation analysis, The result indicated that this model restraining performance is good, the forecast precision is high and simple feasible. This method has provided a new mentality for the submarine tunnel welling up water volume's forecast.
Study on Stability of Underwater Trench of Immersed Tunnel of Hongkong-Zhuhai-Macau Bridge
Authors: Fang Lei , Chen Jun Sheng , Cao Hong , Mo Hai Hong , Liu Shuo Zhuo
Published: September 2011

The studies carried out to appropriate slope ratio for underwater trench of immersed tunnel of Hongkong-Zhuhai-Macau Bridge. A test trench of 100-meter-long and 21-meter-width was excavated under Lingding Ocean along designed axis of immersed tunnel. The trench includes four slope ratio, such as 1:5, 1:6, 1:8 and 1:10. Two actual measurement which includes multibeam measurement and single beam double frequency measurement were used to measure water depth and section form in different time. It is recommended that slope ratio 1:6 can be adopted for underwater trench of immersed tunnel of HZM Bridge.
Analysis on Optimization Construction Procedures of Small Spacing Tunnel in Xiamen Airport Highway
Authors: Wu Li Cong , Wu Ai Xiang , Zhang Yan Kai
Published: September 2011

The small spacing tunnel is a kind of tunnel structural style which situates between ordinary tunnel and double-arch tunnel. It has attracted great attention due to its unique merit. This paper takes Xiamen Airport highway tunnel as an example, considering four different construction steps during small spacing tunnel construction. Author applied MIDAS-GTS software to carry on numerical simulation, the influences of excavating orders of four different construction steps about stratum distortion and stable situation of middle rock pillar are analyzed. The analytical results indicate that construction Step 2 and construction Step 4 can suit actual situation of this project.