Authors studied the basic relationship between flow and occupancy to propose a new criterion for identifying the onset of congestion in the road networks. With the criterion, authors derived some new guidelines for detecting congestion incidents, and could also measure off the traffic stream into four stages. Finally, with the research in above, authors advanced a new detection algorithm for road traffic congestion incidents which was validated by using the data from actual investigation.

Using an empirical cumulative plastic strain formula, a method for calculating the traffic load induced deformation was proposed. Firstly, according to the mechanical properties of soft clays and the traffic load induced dynamic deviator stress, the static failure deviator stress was determined. Secondly, the cumulative plastic strains of each soil layers were then calculated by the empirical equation in which the dynamic deviator stress, static failure deviator stress and number of repeated loading were considered. Finally, the total cumulative settlement of the subsoil was calculated with method of summation of sub-layers. A practical example for the traffic load induced deformation in Shanghai soft clays was presented.

In this paper, through the analysis of basic parameters with the limited displacement theory and iteration method, the clue determing the reasonable design state of this special type of suspension bridge is formed , which regards the cable as the key to the problem. The zero-stress of cable and hanger, as well as the structural behavior in construction state can be obtained through the determination of the cables configuration and internal force of hanger and girder. Based on the theory in above, detailed analysis of a self-anchored suspension bridge with the main span of 328 m is carried out and the reasonable design state is determined when the data about the zero-stress of cable, the excursion of the saddle, the internal force of the girder and hanger under static load are figured out.

By using EMR-8B eye movement recorder, selecting drivers pupil variety of freeway entrance and exit as research object, on the basis of driving experiment, refered to the phenomena of visual turbulence during light and dark adaption, the conversion duration for visual turbulence was selected as evaluation index of drivers visual comfort degree which was used to evaluate the visual load degree and driving safety of tunnel entrance and exit. The results indicate that the driving speed should not surpass 85 km·h^-1 in order to guarantee drivers visual comfort; the stopping sight distance should increase 20~30 m compared to the present standard for tunnel entrance and exit.

Taking the structure of asphalt concrete pavement in actual running as the test object, a kind of actual measurement project for temperature field pavement structure was put forward. Based on the abundant measured temperature data, distribution rules of asphalt pavement temperature field were studied in detail, and the dependency relations between the air temperature and pavement temperature field were discussed with regression analysis. Considering the effect difference to asphalt pavement temperature field which was applied by temperature rise period and temperature fall period of air, the dependency relations between air temperature and different temperature changing periods were researched respectively and the prediction models on asphalt pavement temperature based on different temperature changing periods were established. The comparison between measured and predicted asphalt pavement temperatures indicates that these models have good applicability and accuracy.

The characteristics of semi-rigid base material were researched in four aspects: strength, temperature shrinkage and drying shrinkage, erosion resistance and fatigue. Conclusions are as following: strength of semi-rigid base material can be designed in a quite broad range by the requirement of pavement structure and the strength is obtained not only by the binder but also by aggregations properly designed; cracks caused by drying shrinkage are avoidable by well-timed curing and cracks caused by temperature shrinkage can be reduced evidently by controlling the content of fine aggregate; anti-erosion performance of semi-rigid material can be obviously improved by designing proper material composition, such as reducing the content of fine aggregate, improving the strength of binders and increasing the void of mixtures; semi-rigid base material is stress sensitive material and a pavement will have a longer fatigue life if semi-rigid base can be placed in proper position of pavement.

In order to predict the workability and field performance of asphalt mixture in mix design phase, two asphalt mixtures of different gradation are compacted using SHRP gyratory compactor, and their densification curves are analyzed. The slope of densification curve and densification energy index are introduced to reflect inherent information of asphalt mixture. Furthermore, the two parameters are used to analyze compaction workability and rutting behavior of two mixtures.Rutting test and trial roads are also adapted to evaluate the rationality of the parameters. Test results and analysis indicate that the deformation resistance of coarse gradation mixture is not always higher than that of fine gradation mixture.

In order to optimize signal control parameters, intersection delay should be carefully analyzed and calculated. Adopted signalized intersection theory, based on the research foundation of vehicle delay of fixed-time signal control and the analysis of the vehicle delay on an approach direction of intersection, authors have analyzed and inferred intersection delay formulation directed against the non-saturated and over-saturated traffic conditions of intersection approaches. And authors have applied specific cases to illustrate how to use them. The formulation has indicated the relations among the signal control parameters, vehicle arrival rates and intersection delay and it provides useful information for further studying adaptive signal control method and establishing performance index function of signal control parameters optimization.

Based on a prestressed composite box girder with corrugated steel webs whose span is 40 m, scaled model test girder was designed and constructed. Through measuring deflection and strain of test girder under static loading, shear mechanical property of this type of box girder was analyzed. Finite element method was used to research the influence of the integral size, corrugated steel web thickness, corrugated angle, corrugated depth and flat width on the property of nonlinear shear flexure strength of corrugated steel webs. Otherwise, regression analysis was done on the results of Hamilton's experiment on shear flexure strength with corrugated steel webs and the semi-experienced and semi-theoretical calculation formula of the shear flexure strength with corrugated steel webs was given. The results show that a big part of bending moment is burdened by top slab and bottom slab of concrete; shear force is mainly burdened by corrugated steel web and distributes uniformly along direction of corrugated steel web height.

In order to do research and develop on new type shear connectors applied for concrete joint segment of bridge pylon, aimed at the problem that the conventional push-out test is unable to ascertain the real carrying capacity of shear connectors, a new test method was developed in the fracture test for 31 specimens of seven sub-types in three big types for the investigation and development of new-type shear connectors that can be utilized in steel-concrete joint segment of bridge pylon. The fracture mechanism of each type was studied and the quantitative analysis of ultimate carrying capacity was also carried out according to the experiment results. Then, the uniform calculation formula of ultimate carrying capacity for each new type shear connector was established which can provide instruction in future design and application. Compared with test values, calculated results of the formula agree well with test values.

Through analyzing merit and shortcoming of different permanent deformation test method and evaluation index of asphalt mixture, it was found that dynamic stability evaluation index was not fit to evaluate permanent deformation of asphalt mixture. Based on the compaction theoretical analysis, authors put forward a new evaluation index－complex stability indexto evaluate high-temperature stability of asphalt mixture comprehensively considering compaction period of transition and compaction stability period and gave the calculation formulas of complex stability index using present rutting test equipment. Authors built the correlation model between complex stability index and stiffness modulus, and proved the rationality of complex stability index.

In order to measure the cable tensions of a cable-stayed bridge quickly and conveniently at a construction site, a new measuring system of cable tension was developed according to the random vibration frequency method. With summarizing the principle of the random vibration frequency method, the function, hardware construction and software module of this system were introduced. The ways and means to solve some key technical problems were discussed emphatically using digital filter to restrain frequency confusion of FFT, scanning and confirming main frequency of a vibration signal, and improving calculation precision of a cable tension. The system was based on an AT89C55WD SCM. The functions of a charge amplifying, a signal analyser and a calculator were integrated in an instrument. After a few parameters were inputted, the collecting vibration signal, the FFT of the signal and the estimating cable force could be carried out automatically on line at a construction site.

In order to investigate mechanical performances of prestressed concrete box girder with corrugated steel webs, scaled model test girders are designed, which are based on sizes of foreign bridges. Through measuring deflection and strain of test girders under loading, performances of this type of box girder, including bending, torsion and distortion are analyzed. Test results show that corrugated steel webs bear largely shear, and bending moment is only burden by concrete top and bottom slab under bending. At the same time, deflection of box girders should include influence of shear deformation of steel webs. In addition, resistibility of this type of box girder to torsion and distortion under eccentric loading is low. Distinguished with conventional box girders, prestressed concrete box girders with corrugated steel webs possess itself mechanical performances.

At first, the theory and content of urban transport network design and probabilistic user equilibrium assignment model were introduced. Then, the urban transport network design model under reliability constraint was designed; in this bilevel programming model, the upper model pursued system impedance minimum under investment constraint, the lower model made network reserve capacity maximum with reliability and user equilibrium constraint, and a chaotic heuristic algorithm was presented to solving this problem which could get local or global optimal solution. Finally, a small network example was illustrated and analyzed. The result illustrates that the model can be applied into the reality urban transport and the algorithm is valid in this problem.

根据主梁截面上、下缘的正应力控制条件,综合考虑活载作用以及斜拉索索力对主梁成桥恒载弯矩的可调性,确定斜拉桥主梁的合理预加力数量和相应的恒载弯矩合理域,并根据实际配置的预加力确定主梁恒载弯矩可行域,为斜拉桥的合理成桥状态的确定提供依据.

Hybrid autoregressive integrated moving average (ARIMA) and artificial neural network models were employed in the short-term traffic flow prediction. Using the good linear fitting ability of ARIMA and the strong nonlinear mapping ability of artificial neural network, the traffic flow time series was considered to be composed of a linear autocorrelation structure and a nonlinear structure. ARIMA model was used to predict the linear component of traffic flow time series and the artificial neural network model was applied to the nonlinear residual component prediction. Results show that the hybrid model, which takes advantage of the unique strength of the two models in linear and nonlinear modeling, can produce more accurate predictions than that of single model. The hybrid model can be an efficient method to the short-term traffic flow prediction.

The design method of MR damper for suppression of stay cables vibration was proposed based on the design approaches of structural active control, semiactive control and intelligent control systems.The MR damper for stay cables of Shandong Binzhou Yellow River Bridge was designed by utilizing the proposed design method, and the analysis of the cables incorporated with the designed MR damper was carried out.The control effectiveness of the designed MR dampers reduced the prototype cable wind-induced vibration using semiactive control strategy proposed by HARVOT.Active control, semiactive control and passive-on and passive-off control strategy were verified numerically and compared with each other.The analytical results show that the designed MR damper can effectively reduce the cable wind-induced vibration.The availability and validity of the design method of MR damper for cables were also simultaneously demonstrated through the numerical study on the prototype cables transversely connected with MR damper near the lower anchorage.

Debris flow was simplified as two-phase liquid composed of particles with the same diameter and slurry with the same mechanical features. Assuming that debris flow was one dimension liquid moving to one direction. Authors established methods to calculate impact forces of liquid phase and solid phase by the second Newtons law through calculating velocities and acceleration of every phase, then, obtained general equation to calculate impact force of debris flow. Further, method to calculate total impact time of debris flow through impact formalities, such as impact pits in surface of control structures and impact troughs in bank of debris flow valley was obtained. According to engineering cases to control debris flow, it is obvious that the results between calculating in the methods and observations in real-time field are fitted better, whose relative errors are in 3%, which are permitted in engineering design.

Aimed at a low-angle bedded high rock landslide of a speedway, in order to study on its deformation and failure mechanism, especially to find their similarities and differences of two kinds of low-angle rock stratum, which trends outside or inside slope, according to on the spot investigation and argumentation, deformation and failure, and so on, and on the basis of renewing the initial sloping surface of slope, authors reappear the whole process of deformation failure on the two conditions by choosing the main section of the slope and using the experiment of basal contact friction in physical simulation methods, thoroughly analyze the deformation of different phases and the final failure mechanism, and eventually confirm that the failure of slope, which rock stratum dips outside, is ascribed to sliding-compression cracking and its interlaminar sliding is remarkable;and the slope, which rock stratum dips inside, on the whole is in the stabilized state and has no obvious phenomenon of interlaminar sliding.

In order to research the dynamic characteristic of asphalt mixture, different kinds of dynamic moduli and phase angles of asphalt mixture were tested using Superpave simple performance tester (SPT). Authors analyzed the influence of temperature, frequency and confining pressure on the dynamic characteristic of asphalt mixture. Based on the time-temperature superposition principle, the master curves of dynamic modulus of asphalt mixtures were determined by using non-linear least squares regression techniques and predicted the dynamic modulus by using the revised Witczak model. Results show that temperature and frequency have the same influence on the dynamic modulus and phase angle of asphalt mixture, and the influence of confining pressure depends on the test temperature and frequency. Moreover, the master curves of dynamic modulus are continuous and smooth, while none of the phase angle master curves are continuous, and the dynamic modulus values of asphalt mixture are predicted very well by using the revised Witczak model.

Authors designed and made 44 PBL test samples composed of 15 different groups; accomplished the ultimate bearing capacity tests of the 44 test samples; studied and analyzed the influence of all kinds of factors on the ultimate bearing capacity of PBL shear connectors; compared the test results of PBL both with that of studs and with that of calculated results according to the PBL bearing capacity formula put forward by specialists at home and abroad and some conclusions were educed. The conclusions show that PBL has great bearing capacity and good ductility; the size of the holes on the steel plate, the size and strength of perforated rebar, the strength of concrete and the ratio of stirrup reinforcement are the main factors influencing the ultimate bearing capacity of PBL shear connectors; the number of holes and perforated rebar, the size of each test samples also have influence on the single ultimate bearing capacity of PBL shear connectors to some extent; the single hole ultimate bearing capacity of the close perforated PBL shear connectors is nearly same as the studs with same diameter as the perforated rebar; while the single hole ultimate bearing capacity of the unclose perforated PBL shear connectors is much greater not only than that of the studs with same diameter as the perforated rebar, but also than that of sum of the anti-shear ultimate bearing capacity of perforated rebar and concrete tenon.

In order to solve the problem that the present evaluation system gives no consideration on accelerating aging effect of ultraviolet radiation for asphalt binder, authors compared the ultraviolet aging with thermal aging for five kinds of asphalts by comparison tests, dynamic shear rheometer(DSR) test, bending beam rheometer(BBR)test and infrared adsorption spectrum analysis. Results show that asphalt has different sensitivities between thermal aging and ultraviolet aging condition. The ultraviolet aged asphalts compositors on penetration, softening point and ductility tests dont accord with thermal aged asphalts. Ultraviolet aging and thermal aging give asphalt different influences, rheological property changes greatly after ultraviolet aging. Inner reason of anti-ultraviolet aging ability of different kinds of asphalts is determined by aging reaction degree. Aromatic blend and resin are two main influence factors of asphalt anti-ultraviolet aging ability. Therefore, evaluation result based on thermal aged asphalt may not reflect asphalt anti-ultraviolet ability exactly, and ultraviolet aging research is necessary in the intensive ultraviolet radiation region.

In order to deal with the problems of damage in orthotropic steel deck and fatigue crack in steel deck structure, an innovative composite bridge deck system with orthotropic steel plate and thin reactive powder concrete (RPC) layer was presented. Finite element models were established on the basis of a certain bridge. Pure steel girder and composite girder were created respectively to compute tension force in the main cable and stress state in bridge deck system. Then, static load experiment of full-scale composite beam model was carried out. The results show that tensile stresses in steel deck decrease obviously when the innovative steel-RPC composite deck system is adopted and the maximal reducing amplitude is over 70%. But the tensile force in main cable can hardly increase. Tensile stress of the RPC layer is up to 42.7 MPa before tiny cracks appear, which is much greater than 10.08 MPa in calculation. Stiffness of original orthotropic steel deck can be improved by the composite bridge deck system. Consequently, stress in orthotropic steel deck decreases greatly, which will effectively eliminate the risk of fatigue cracking in steel deck.

A 3-D finite element model for Runyang Yangtze Highway Nancha Suspension Bridge was established with ANSYS software, on the basis of which self-vibration behavior analysis was carried out using subspace iteration method. The multi-accuracy simulation technique of the central buckle and influence of the central buckle on dynamic behavior of the long-span suspension bridge were particularly studied. Results show that different accuracy simulation of central buckle has a little influence on dynamic behavior of the bridge; compared with short hanger cable at mid-span, the structural rigidity is raised and the natural frequencies increase by use of central buckle, but various types of vibration modes are affected in different extents; among all of these vibration modes, the cable-related modes are most obviously affected. The results obtained in this paper provide essential information and research basis for health monitoring of the bridge.

Authors took the material characteristic of concrete-filled square steel tube (CFSST) into consideration and turned the corner non-uniform confinement force of CFSST to its corner uniform confinement force through the equivalent reduction factor, which considered the thickness side ratio effect, based on the unified strength theory. Thus, the non-uniform confinement force of square steel tube to its core concrete could be turned to the uniform force of equivalent circular steel tube. Based on unified strength theory solutions of thick tube, authors deduced the formula for calculating ultimate bearing capacity of concrete-filled steel tube. Formula solutions was testified by test results of reference. The applicability of the formulas was testified. The result shows that the formulas have significance in exerting material potential and saving material.

From a new viewpoint of transportation efficiency,authors propose the aggregative total travel time to measure the level of transportation efficiency and macro-accessibility of one given land-use pattern. By dividing the total travel time into aggregative inter-group travel time and intra-group travel time,authors deduce the function of total travel time and establish an urban land-use optimum model, which can maximize the transportation efficiency and macro-accessibility under certain restrictions of economy, land and population. Finally,authors attempt to solve the optimum model from the viewpoint of integrated urban land-use,transportation system planning and propose a solving method which can realize the circular relationship between urban land-use pattern and transportation system.

基于公共汽车交通优先控制理论的背景,研究了信号控制交叉口公共汽车优先信号的确定方法,提出了系统最优的线性规划模型,并利用算例演示了提出的定周期条件下公共汽车优先信号的确定过程.研究成果对于进一步推行公交优先,改善城市的公共汽车交通具有重要的理论意义和实用价值.

Against the current status for the loess tunnel with saturated loess around the rock in the gate of loess tunnel that the strength of surrounding rock is low and the ability in self-support is bad and the construction is very difficult, on the basis of measuring the gelation time of cement-silicate grout and compression strength of grout binder at different mixture ratio and temperature in the laboratory, authors research the technical parameters by the field grouting test, such as mixture ratio, grouting pressure, diffusion radius of grout and grouting technology. The results show that parameters of cement-silicate double solution grouting are suggested as follows, at the construction of loess tunnel: silicate modulus M=2.8~3.1; silicate liquor strength Be′=35~40; water-cement ratio W/C=0.75:1~1.0:1(ratio by weight); cement-silicate ratio is 1:0.5~1:1.0(ratio by volume);grouting pressure is 0.6~3.5 MPa;diffusion radius of grout is 0.5~1.3 m. The engineer practice shows that the method of cement-silicate grouting can be achieved good effect for reinforcing the saturated loess in the gate of loess tunnel.

For establishing long-term mechanism to solve overload and oversize transportation, authors firstly established a mathematic model to evaluate transportation enterprises income, and analysed relation between profit and price, transportaion cost, and fine because of overload. And then, authors analysed how an enterprise could earn the biggest profit. On the basis of reviewing characteristics of Chinese freight transportation market, authors analysed possible behavior choice of transportation operator according to game theory. Learning experience of solution to overload and oversize transportation from United States, authors analysed 4 enforcement measures, and their characteristics and effects.Authors gave advice to Chinese situation on the basis of analysis above.In order to promote performance of solution to overload, suggestions on government regulation and economic measure were stated at the end of the paper and it would play an active role on overload and oversize transportation.

Several key problems of pile-supported reinforced embankment were studied by elastic-plastic finite element method, including the composition and distribution rule of the settlement, the applicable situation and the influence factors of pile efficacy. The settlement rule of embankment at unembedded soft layer with different heights, the rules of pile efficacy changing with slab size, pile spacing, embankment height at embedded in soft layer or not and the effect of geogrid were analyzed. The results show that settlement of embankment is mainly determined by compression of the substratum;pile efficacy increases with increase of size and embankment height, and decreases with increase of pile spacing;geogrid has no significant impact on pile efficacy and the embankment settlement.

The mechanical response of pavement on the orthotropic steel deck under wheel loading and the effects of various thickness of modulus of upper layer and lower layer on the mechanical indexes of pavement are analyzed by finite element method, and the responses of various pavement projects under overload are studied.The research results show that the total paving thickness and the modulus of lower layer have more effects on the shear stress between the steel deck and the paving, and the modulus of upper layer has more effects on the maximum tensile stress on the surfacing.The results can provide the theoretical base for the paving design of orthotropic steel deck.

The rock and soil around tunnel is considered as a stochastic medium and the movement in it due to tunnel excavation is considered as a stochastic process in this paper.By using the stochastic medium theory, the ground surface movement and deformation in longitude along the tunnel due to its excavation are calculated and analyzed. The formulas of ground surfaces subsidence, horizontal displacement, inclination, horizontal strain and curvature in longitude along tunnel are deduced. An engineering example shows that the calculating results tally well with the measuring results. Based on these, some basicregularization of ground surface movement and deformation in longitude along tunnel due to its excavation are summarized, and a conclusion that only ground surface buildings in the range of 2R on working face are influenced obviously by tunnel excavation is drawn.

The six graded curve are selected for ultra-thin asphalt concrete SAC-10.The comparison testing of GTM(Gyratory Testing Machine) and MARSHALL is completed.The mechanics index and volume index are tested and comparison analysis is completed.The testing result is proved that the middle gap-graded is half-open-gradation, the characteristic of half-open-gradation which the content of bigger than 4.75 mm is 70% and 65% is that the two indexes of GSI and GSF in GTM testing for asphalt concrete are up to the standard when the asphalt to aggregate ratio increases from 4% to 6%, the capability for high-temperature everlasting deformation resistance is better than whole gap-gradation.The half-open-gradation can be used for ultra-thin layer.

By phase optimization design on arterial road coordinate control system, a new offset model for arterial road coordinate control was established. Authors considered all the factors, such as road average speed, traffic flow dispersion, turning traffic flow from crossway and asymmetry of vehicles arrival distribution in the model which greatly influenced the control effect of arterial road coordinate control scheme. Total delay and total parking number were taken as the offset model output, and the rules of two directional traffic flow delay at the intersections were particularly analyzed. Moreover, programming calculation of Matlab was introduced to realize the optimization of the offset. Results show that the optimized model can provide a new approach for offsets optimization of arterial road coordinate control system.

Based on the complexity of working properties on pile-supported embankment,and unclearness of common working mechanism among embankment,pile and soil,authors establish the balance equation considering stress-deformation coordination of soil-pile-embankment,analyze the load transfer property of them and get the results of soil arching,loading sharing of soil and pile,the settlement of pile and soil. Contrasted with elastic-plastic finite element,the method is verificated reasonable.Using this method,authors analyze the widen engineering of Hangyong freeway.

The concept of travel trait is introduced to describe travelers' route choice criteria under uncertain environments.The travel trait is defined as the linear weighted sum of the travel time and travel time reliability.Authors integrate two different important factors that have significant impacts on the route choice:the travel time and travel time reliability.Assuming travelers' standard of choosing the path which perceives travel trait cost is minimized due to stochastic variations of link capacities, a stochastic user equilibrium assignment model based on travel trait is formulated.The equivalence and uniqueness of the solution of model are demonstrated.Then, MSA algorithm is cooperated with the model.Numerical results of a small network show that the proposed model can reflect the travelers' route choice behavior in stochastic road networks.

Authors present a network equilibrium model for investigating travel behavior with combined travel mode under elastic demand. Using the network equilibrium theory and super network approach, an equivalent variational inequality model is proposed. Moreover, the properties of the proposed model are also discussed. A solution algorithm for solving the model is proposed and validated by a numerical example. The results show that the proposed model can truly capture the travel behavior with combined travel mode. This study can help to deepen the understanding of travel behavior,reasonably plan and layout parking transfer facilities and coordinate the development of multiple transportation modes.

通过系统的试验研究,分析验证了磨细橡胶粉改性沥青的主要特性和路用价值,并通过生产工艺的改善,促进了这种改性沥青混凝土在路面工程中的应用.

A two-dimension unsteady seepage FEM program is developed on the basis of unsaturated seepage pattern to simulate transient seepage fields due to rainfall infiltration for popular high road fills. The water content and matric suction in the slope are analyzed. An extended MOHR-COULOMB failure criterion is used to allow for shear strength variations as a result of changes in matric suction, thus the safety factors are calculated. In addition, effects of various rainfall events, angle φ^b and the anisotropic permeability ratio caused by construction of the embankment on the seepage stability are analyzed.

In order to explore the nonlinear fatigue damage characteristics of asphalt mixture, the linear and nonlinear fatigue damage models were introduced based on the elementary theory of fatigue damage. The fatigue damage model of asphalt mixture was established based on strength and fatigue life (S-N) equation. The fatigue damage process of asphalt mixture was analyzed. The fatigue damage equation of asphalt mixture was established according to the theory of damage mechanics and S-N fatigue equation. The damage function and damage evolution equation were deduced. The calculation model of fatigue dynamic load strength which has the same loading waveform and loading rate was deduced by the fatigue damage equation. The calculation models of actual initial stress level and critical fatigue damage degree were also obtained. Results show that the material damages at failure include the fatigue damage and the static damage. Fatigue damage for asphalt mixtures has nonlinear characteristics. One of the prime reasons which result in discreteness of fatigue test results is the correlation between fatigue dynamic load strength and loading rate.