西南交通大学学报

Calculation of Reliability Index and Resistance Partial Coefficients of Bored Pile Ultimate Bearing Capacity

LUO Shu-xue

2000, 13(4): 261-265.

[Abstract](1299)

Abstract:
Based on treatment and analysis of the testing data of piles, a formula for calculatingthe ultimate bearing capacity of bored piles is proposed by employing the reliability principle and analysis method for piles. Resistance partial coefficients of piles are determined by computation, and the computed bearing capacity of this type of piles is checked by engineering example.

An Introduction to Hopf Algebras, Yang-Baxter Equation and Quantum Groups

WANGMing-yi

2000, 13(4): 325-329.

[Abstract](1125)

Abstract:
It is well known that Hopf algebras, Yang-Baxter and quantum groups are three main research directions in modern mathematics and come fromthree different disciplines. In this paper, the development of Hopf algebras, the origin of Yang-Baxter and the prevailing of quantum groups are introduced. In addition, the close connections among them are presented, in which some points of view are due to the author of this paper.

Dynamic Response Features of High-Speed Track in Frequency Domain

LIUXue-yi, WANG Pin

2000, 13(4): 335-339.

[Abstract](1399)

Abstract:
According to the action properties of high-speed wheel/rail system, an analysis method is developed for studying the dynamic responses of high-speed track in frequency domain. The features of dynamic responses in frequency domain of high-speed track are investigated, and the influences of the track stiffness and damping on its vibrations are analyzed, with some features about dynamic effects in high-speed track obtained.

Analysis of Three Dimensional Elastic-Plastic Stresses of Rail under Non-Ellipse Contact Area

LUHui, SUNGuo-ying

2000, 13(4): 340-343.

[Abstract](1448)

Abstract:
The calculation of wheel/rail contact stresses is an important project in wheel/rail relations. In this paper, a model forwheel/rail with arbitrary profiles contacting in an arbitrary point is built to calculate contact area and contact surface stresses. Then bytakingthe calculated surface stresses as applied load, the stresses inside the railhead are calculated through the three dimensional elastic-plastic finite element method. Final calculations showthat the method presented in this paper is applicable to the calculation of wheel/rail contact stresses characterized by complex profiles.

Simulation Calculation of Lateral Impact Force Acting on Guard Rail while Passing Through Turnout Zone on the Side-Way

RENZun-song, ZHAI Wan-ming, WANG Qi-chang

2000, 13(4): 344-347.

[Abstract](1345)

Abstract:
Using the flange clearance and the wheel/rail dynamical clearance, a method is presented to calculate the lateral impact force acting on the guardrail. Based on a vehicle/turnout spatial coupled vibration model, the dynamic responses of the guardrail are calculated by simulation when the vehicle passing through the No. 12 speed-raised movable-point simple turnout.

Study on Nonlinear Wind Resisting Static Stability of Catwalk of Suspension Bridge

ZHENG Shi-xiong, ZHOUShu-hua, LIAOHai-li

2000, 13(4): 348-451.

[Abstract](1723)

Abstract:
By measuringthe static aerodynamic coefficients of the three components of forces through section model test and taking into account the components of the displacement-dependent wind load and geometric nonlinearity, the authors of this paper propose a nonlinear finite elementmethod (FEM) to assess the static stabilityof catwalk of a suspension bridgewith amiddle span of 960 m. Meanwhile, a full model tunnel-test of the catwalk is also performed. By comparing the displacements measured in the full model tunnel-test with the results obtained from the nonlinear FEM, it is shown that the nonlinear FEM can efficiently assess the stability of catwalks of suspension bridges as the full model test.

Structural Behavior Nonlinear Analysis of Tied Arch Bridge with Concrete-Filled Steel Tubes During Construction

ZHAOLei, BUYi-zhi

2000, 13(4): 352-356.

[Abstract](1399)

Abstract:
Being aimed at the third bridge over Fu river in the city of Mianyang, Sichuan, a tied arch bridge with concrete-filled steel tubes andwith a main span of 202 m, a 3-dimensional compound structural calculation model constructed by flat shells, beams, trusses and rope elements is used to analyze the structural behaviorof the bridge. In the analysis, the structural nonlinearity and ultimate bearing capacityof members are considered, and the deformations during construction and the superposition effectof stresses are also taken into account. The emphasis of the study is focused on the deformations, internal forces and stability of the bridge during construction.

A New Type of Bridge Plate Rubber Support Resistant to Lateral Displacement

ZHENG Zhi-ou, ZHENG Shi-ying

2000, 13(4): 357-360.

[Abstract](1121)

Abstract:
Bridge plate rubber support has many advantages. However, its lateral displacement is considerable for bridges on high-speed railways, which is a hidden danger in train driving. In this paper, a new material and a newconcept are used, thus the compression stiffness and longitudinal shear stiffness can keep fairly lowwhile the lateral shear stiffness increases greatly. The static force performance test and the fatigue examinationwhich simulates the motive force of the runningtrain prove thatthe capabilityof resisting lateral displacements of the developed new type bridge plate rubber support is able to achieve the desired objectives. Moreover, because of the same formal sizes, the new rubber supports are convenient to be replaced in the railway reconstruction for higher speed.

Reliability Analysis of the Pile Shaft of Bridge Pile Foundation Structure System

WANSi-ming, ZHAO Shan-rui, HUANG Guang-sheng

2000, 13(4): 366-370.

[Abstract](1505)

Abstract:
Based on the analysis of pile shaft load and resistance uncertainty, the reliability indices of pile shaft members are calculated. According to the minimum reliability index prescribed by design, the critical value of the pile slender ratio is determined.

Study on Resistance Partial Coefficients of Piles

PENGXiong-zhi, ZHAO Shan-rui, LUO Shu-xue

2000, 13(4): 371-374.

[Abstract](1043)

Abstract:
According to the statistics of resistance in 78 bored piles and 128 drilled piles, the resistance partial coefficients of the bored piles and drilled piles are studied using calibration method. Results show that the partial coefficient of the main resistance is affected greatly by its distribution type. The partial coefficients of resistance obtained by recurrence analysis method have clear physical concepts. The calculation method is reasonable and the obtained results are credible.

On Construction of Continuous Operation Reference System for Differential GPS Satellite Navigation and Positioning

HUANGDing-fa, DINGJian-wei, XIAJie

2000, 13(4): 375-378.

[Abstract](1282)

Abstract:
Establishing a continuous operation reference system (CORS) for satellite navigation and positioning is the inevitable tendency in further developing and exploring GPS technique application. This paper mainly describes the structure and technical indexes of CORS, and analyzes critical techniques of the system. It also presents the structure design of CORS combing a practice of establishingthe CORS in cityC. Operation experiments in practice showthe feasibility and effectiveness of the system.

The Prerequisite to Investment in High-Speed Railway in the View of Market Demand

LIUWan-ming

2000, 13(4): 379-382.

[Abstract](1588)

Abstract:
The author uses utility theory and multiple object decision making approach to analyze the choice behavior of the individual, then establishes a model to research the passenger traffic market shares of three travel modes, in which the travel distance and the value of time (VOT) are included as variables. After analyzing the applicability of high-speed railways to passenger traffic market demand, the author puts forward a recommended prerequisite to investment in high-speed railway, expressed in social average VOT.

Technical Evaluation for Urban Rail Transportation Networks

WANG Zhong-qiang, YANQi-peng, GAO Shi-lian

2000, 13(4): 383-386.

[Abstract](1378)

Abstract:
Evaluation for urban rail transportation networks (URTN) includes three main points: financial analysis, national economic analysis and technical evaluation. Since URTN is different from other urban transportation modes, this paper mainly dealswith the systemofURTNtechnical evaluation indexes. Using the method of systems analysis, it points outthattheURTNtechnical evaluation systemshould comprise four aspects,i. e., demand evaluation, supply evaluation, network characteristics analysis and sustainable development evaluation. Meanwhile, qualitative and quantitative methods are combined to discuss the indexes and analyze them with examples. The system of evaluation indexes and the calculation method proposed in this paper are valuable forURTN planning both in theory and in practice.

Research on Optimum Computer Networks Design

LI Cheng-Zhong, DENG Chao-jian, LIAng

2000, 13(4): 387-390.

[Abstract](1382)

Abstract:
Because of the technique progress in computers and the quick development in communication networks, the optimum design of the link capacity has become a key problem in the computer networks. In this paper, a method for the optimum design of the computer networks link capacity is proposed, by which the overall optimum solution can be abtained. The method applies to the link capacity optimumm designs in centralized networks and distributed networks. For illustration, an example in design is also presented.

Study on the Signal Communication System of Maglev Trains

YANGJian-yong, LIANJi-san

2000, 13(4): 391-394.

[Abstract](1169)

Abstract:
The composition, functions and realization method of the signal communication systemforMaglev trains are discussed. In viewof the characteristics ofMaglev trains, the data flowof the system is analyzed, inwhich the emphasis is given to the data exchange between the facilities in the vehicle and those in the control center. Several schemes are raised, and the most possible one for current stage is determined by comparison based on practice,

The Structure and Performance of High Rate Turbo-Codes

ZHANG Zhong-pei, JINFan

2000, 13(4): 395-398.

[Abstract](1215)

Abstract:
There are multi-dimension and punctured methods for constructing Turbo-codes. The interleave design and punctured matrixstructure in constructingTurbo-codeswith the punctured method are discussed. Through the analysis of the free distances and decoding of high rate Turbo-codes constructed by the above two methods, their bit error limits are obtained, fromwhich theTurbo-codes constructed bymulti-dimension method are found to have better performance than those by punctured method, but with more complex decoding and bigger time delay. Comparison shows that with better compromise in performance and implementation complexity, the punctured method is an ideal scheme to construct high rate Turbo-codes.

Nonlinear Dynamic Analysis for Railway Freight Cars

ZENGJing, WANG Yong

2000, 13(4): 399-403.

[Abstract](1626)

Abstract:
The concepts of linearity, nonlinearity and real critical speeds for railway vehicles are introduced in the first part of this paper. Then a nonlinearmathematical model for a railway freight carwith 31 degrees of freedom is set up, inwhich the nonlinearity arising fromthe friction forces andwheel/rail interactions are considered. Numerical method is used to investigate the hunting stability behaviors of the freight car, including the limit cycles, quasi-periodic solutions and chaos in the system.

Recursive Identification Methods for Control Model of Tilting Car Body Test Rig

YANGMing-li, ZHANGHan-quan

2000, 13(4): 404-408.

[Abstract](1545)

Abstract:
Based on the general I/Omodel structure, an off-line identification of the lowfrequency dynamic features of a tilting car body test rig is studied using four different parameter evaluation methods. The accuracy of the obtained model is proved through comparing the I/O results in model simulation with the practically measured results.

Study on Polaron Properties in Asymmetric Double Heterostructure of Semiconductors

WENCheng-zhong, JIANG Guang-zuo

2000, 13(4): 409-412.

[Abstract](990)

Abstract:
The polaron ground state in asymmetric double heterostructure (ADHS) is studied. Using perturbation method, the binding energy and effective mass of a polaron are calculated and expressed as the functions of the width of the center layer. In considering electron-phonon interactions, both the confined longitudinal optical modes and the interface phonon modes are included. The results differ largely fromwhat is in symmetric double heterostructure (DHS), for the contribution of the interface phonons is larger and wider than in DHS, showing that the asymmetry in structure has a profound effect on the properties of ADHS.

A Study on Correlation Searching System for the Laws and Regulations in Railway Transportation

JIANGNan, TANZhong-ping, HEFu

2000, 13(4): 413-416.

[Abstract](1287)

Abstract:
The computer management and consulting system for railway transportation laws and regulation is studied in depth. The concept of”meaning cluster”is put forward, and the correlation is mathematically defined. On this basis the mathematics model and data structure of correlation searching for computer realization are described, and finally an algorithm is presented.

A Method for Integer Programming Problem by Theory of Groups

LIQing-song, ZHOUShuang-gui, DUWen

2000, 13(4): 417-420.

[Abstract](1259)

Abstract:
There are so many methods for the problem of integer programming (IP); however, available methods connected with theoryofgroups are still given little consideration. This paper, in orderto predigest the process of solving the IP problem, attempts to divide the IP problem into a series of simple models by using the decomposing theoremof limited groups—significant both in theory and in practice. Based on the translation and loosing operation of IP problem, the steps of transformation and decomposition to the group programming model are discussed in detail, and solutions to two decomposition results are also discussed.

Analysis of Organization Mechanism and System of Human Error in Enterprises

YUANXu, WUZhen-ye

2000, 13(4): 421-424.

[Abstract](1133)

Abstract:
Based on investigation and analysis of the safetymanagement status quo of enterprises, the safety managementmechanism mode for enterprises is set up. The internal and external conditions of the mode operation, change and conversion are analyzed, and the main characteristics ofthe preferable mechanismare presented. Meanwhile, the safetymanagement systemmode for enterprises is built, and the centralizing and organizing of the systemmode are discussed. The mechanism and systemmodes proposed in this paper can be used to survey and analyze the situation of safety management in enterprises.

A Global Saturation Theorem for the Mixed Exponential Type Integral Operators

TIANJun, PENGJian-hua

2000, 13(4): 430-433.

[Abstract](1002)

Abstract:
A general exponential type integral operator, called mixed exponential type integral operator, is introduced, and the properties of this type of integral operator are studied. Based on the improved Bajsanski-Bojanic parabolic method and the related properties of integral operators, a global saturation theorem for the mixed exponential type integral operatorLnis established. So, the saturation results of some operators including Baskakov operator can be obtained easily, hence laying a basis for studying the approximation transformation theoremof the mixed exponential type integral operators, and presenting a new method for studying the saturation problems.

A Fuzzy Control Method for Compelling Stable Strategy

ZHAOHai-liang

2000, 13(4): 434-439.

[Abstract](1424)

Abstract:
Based on the varying trend of the on-line identification controlled object’s output state, a new approach to compelling stable control strategy is presented. It can eliminate the oscillations of the conventional fuzzy logic controller, whichoften occurwhen the systemparameters change. In addition, some concepts, such as the shape function vector of a curve and the monotonic smooth transition system, are proposed. The dynamic performance of the new controller is discussed theoretically using these new concepts.

The Stability of a Nonautonomous and Nonlinear System

LIUChang-dong, YUXiao-hua

2000, 13(4): 440-443.

[Abstract](1270)

Abstract:
The stabilitytheoryof a kind of nonautonomous and nonlinearsystem is discussed usingthe scalar quantity functionV(Liapunov) forthe decomposition theoryof large systems. The sufficient condition ofthe asymptotic stabilityof the system is obtained, and in the meantime, a corollary forthe asymptotic stability is derived when the nonlinear term of the system is weakened.

Study on the Relationship among Geometric Quantities of Riemannian Monifolds

GUO You-rui, SHUAIBin, LIUHai-yan

2000, 13(4): 444-446.

[Abstract](1141)

Abstract:
To study the relationship among geometric quantities (the curvature, the diameter and the volume) ofRiemannianmonifolds is a significant project in geometry. As to the questionwhetherthe volume V(M)has a positive lower bound for them-dimensional Riemannian monifoldsMsatisfying that the curvatureK(M)≥1, the diameterd(M)≥γπ,0<γ<1,this paper gives a negative answer through constructing an ellipsoidal model and directly calculating the geometric quantities. Thus the problem is thoroughly solved from one aspect

Researches on the Comparing-Mapδon the Symbolic Space(Ⅱ)

LIUJia-cheng, MEIXue-feng, GUO Yao-huang

2000, 13(4): 447-449.

[Abstract](1091)

Abstract:
The comparing-mapδon the symbolic space is topologically conjugate to the shiftmapσ.In this paper, characters about eventually periodic points ofδandσare studied ,it is proved thatδandσon the symbolic spaceΣ2have the same eventually periodic points set ,i. e.EP(δ)=EP(σ),and some relations between the eventually periodic points ofδandσare obtained.

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2000 Vol. 13, No. 4