Applied Mechanics and Materials Vols. 204-208

Abstract: Obtained through the large number of field core samples from a variety of strength tests, the impact of the construction technology of concrete pavement structural strength spatial variability of the distribution law of the strength of concrete in the pavement structure, to find out the variability characteristics of the structural strength, to determine the structural design of reliability coefficient to provide a basis. On the basis of theoretical studies and experimental studies, practical techniques for pavement concrete structure and properties of the variability of design control and construction control, to control the variability of pavement concrete structural strength.

Abstract: On the basis of defining the concept of rural highway project performance, the necessity of the project performance evaluation of rural highway is analyzed. According to the theories of government's public function, fiduciary responsibilities accountability and public finance, the relation between rural highway and public finance are made researches on. Furthermore,with the application of the demand level theory of Maslow, the interrelationship among objects of the rural highway project performance evaluation is made an analysis of, and on top of that, combined with SWOT analysis method, the demand and goal of rural highway project performance evaluation are put forward.

Abstract: Based on the theory of hierarchy analysis, the post-assessment indexes system of cold recycling technology project have been established, and the hierarchy analytic procedure have been used to determine the weighing coefficients for post-assessment indexes of cold recycling engineering of asphalt pavement, and the weighing values for various levels factors were given for the cold recycling base layer project of highway of Shenyang-Yingkou. Considering the road performance and economic benefit, societal and environmental benefit, the analytic hierarchy procedure (AHP) method can effectively avoid making wrong decisions subjectively and made it more scientific and reasonable to determine the weighing values of post-assessment indexes, and it is an effective method to determine the weighing values for post-assessment indexes of the cold recycling technology project.

Abstract: Topographic, geologic and environmental condition is complex in mountainous area. Many factors impacting mountainous highway routing decision-making. The factor’s weight is variable and influence with each other. Variable analysis method is used to determine the weight of decision-making factors. The research use Grey Theory to build model with the factors to compare with alternative plans and calculate the optimistic one. Finally we bring out the Decision-making model of mountainous highway routing base on variable weight. The model can provide a new method for highway routing decision-making.

Abstract: When a train runs across a bridge, vibration energy is transmitted from the track structure into the bridge deck and other components which act as different size of ‘sounding boards’. These ‘sounding boards’ also radiate noise, namely, re-radiated noise, which results in ‘hot spots’ in noise maps for bridge sections. Based on the field tests on the noise of 32m double line simply-supported PC-box girder serviced in Chengdu-Dujiangyan High-speed Railway (CDHR) in China, mathematical logarithmic equation for predicting the equivalent A-weighed noise level (LA,eq) is proposed. Predicted results are compared with field ones and the non-parametric tests including two-related samples Wilcoxon and two-independent samples Kolmogorov–Smirnov are carried out, indicating satisfactory results and verifying the reliability of theoretical model. Analysis shows that equivalent A-weighed noise level detects no significant difference between the model predictions and the field measurements at the confidence level of 95%.

Abstract: Resonant pavement breaker is an excellent technique to reform worn cement concrete pavement (PCC). When the frequency of the machine adjusted to the resonant frequency of the worn cement concrete pavement, the pavement will be broken to discrete blocks. For the full use of this technique, this article studied the dynamic properties such as natural frequencies and modalities of worn cement concrete pavements of national secondary road. FEM was used to discretize models of different damaged degrees. The influence of different damaged degrees on natural frequencies and modes was studied. It was discovered that the new cement concrete pavement’s frequency was bigger than worn ones, and the modes were influenced by the damage locations and their degrees, the more worn, the more irregular.

Abstract: The characteristics of soft clay roadbed settlement prediction model are studied in this paper. Firstly, based on one-dimension soil consolidation theory, the shape of time-dependent settlement process curve was analysed. Then, Mathematical analysis of traditional settlement models, including Gompertz model and Logistic model, was conducted, and the mathematical deficiency of above two traditional models were pointed out, which the settlement corresponding to inflection point has a constant ratio to the ultimate settlement. Further, Weibull model was proposed to describe the time-dependent settlement process of roadbed. This proposed model overcomes the deficiency of above two traditional models, and exponent model is one of its degraded expressions. Moreover, it can predict the total settlement processes of both the instantaneous load and the ramp load conditions. Finally, according to a group settlement observation data, the prediction results of different models are compared, and Weibull model has a good agreements.

Abstract: According to the computing formula of the effective relative density of aggregate and its physical significance, the theoretical computing formula of asphalt absorption coefficient C has been deduced through the Four-phase system theory of aggregate, and the rationality of asphalt absorption coefficient has been verified through testing and comparison with other computing methods. It is concluded that: (1) the asphalt absorption coefficient is between 0.2 and 0.8 when the water absorptivity of aggregate is between 0.5% and 4.0%; (2) the formula of asphalt absorption coefficient should includes bulk relative density of aggregate; (3) when the water absorptivity of aggregate goes up, the impact exerted by the bulk relative density of aggregate upon the asphalt absorption coefficient would be greater accordingly.

Abstract: The planning and argumentation of two intercity railway (IR) projects (Lanzhou-Zhongchuan, Xi’an North Passenger Station-airport) in Northwest China have attracted more and more attention by Chinese Central Government, local governments in Northwest China and some research organizations recently. In order to explore and find out the right way of IR development in Northwest China, we must combine with characteristics and uniqueness of Northwest Provinces, research the question more comprehensively. This paper aims at estimating the strategic impacts of IR construction on regional economy, society and environment in the future systematically, especially on the development of economy. So we choose Lanzhou-Zhongchuan IR as an instance, research this problem based on previous project experiences on it and actual dates provided from No.1 Survey & Design Institute of the Ministry of Railway (MOR). By introducing Scenario analysis method, this paper systematically enumerates and concretely analyzes the opponent viewpoints combining with the decision-making tendency of saving cost, protecting environment, promoting social and economic harmony in transportation planning. And then we make certain what are the critical conflicts in value judgment, select and determine the right construction scheme of the IR from three interactive perspective scenarios. The key technical difficulties and breakthroughs of our research are expressed, such as determination of necessity factors’ weight, forecasting traffic demand of the IR, regional economic impact of the IR and so on. It is expected that scenario analysis method would be helpful for decision-making of IR constructions in the future. And we hope to report further on this in subsequent papers.

Abstract: The author of this article gives a detailed description of the basic situation of the coastal expressway, focusing on the characteristics and engineering properties of soft soil as well as a in-depth analysis of the successful soft soil foundation treatment technology using cement mixing pile. This article provides useful reference for engineers facing similar situation.