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In light of psychological and physiological behaviors of drivers, this paper discusses design issues regarding tunnel portal shape and ambient landscape with the purpose of reducing risks to drivers entering a tunnel. The results show that the portal shape and ambient environment should be integrated, and it is recommended that the landscape be monotonous and unified. It is necessary to: conceal the surrounding engineering facilities as much as possible to reduce visual distractions, avoid the engraving of tunnel names, decrease the brightness around the tunnel portal, prohibit excessive embellishment, and restrict the use of symbolic portals. Source

Xi Z.,Nanjing Southeast University | Xi Y.,Nanjing University of Science and Technology | Xiong H.,Jiangsu Transportation Research Institute
Journal of Bridge Engineering

There are different connection patterns between the bridge decks and pylons of cable-stayed bridges. This paper presents an energy method of analysis for the in-plane ultimate load capacity of cable-stayed bridges with different deck and pylon connection patterns. The potential energy of the whole bridge, including the bridge deck, stay cables, pylons, and work done by external loads, is considered in the development of the bridge energy equation. The energy of the plastic zone is introduced into the bridge energy equation. Both geometric and material nonlinearities are taken into account in the analysis. The predictions of the proposed method show good agreement with experimental and ANSYS results. © 2014 American Society of Civil Engineers. Source

Chen Z.-J.,Hohai University | Zhang N.-N.,Hohai University | Zhang X.-W.,Jiangsu Transportation Research Institute
Journal of Central South University of Technology (English Edition)

In order to realize information construction on settlement of pile-group foundation of Sutong Bridge, the monitoring instruments of high-precision micro-pressure sensor and hydrostatic leveling and settlement profiler were integrated synthetically. A set of practical multi-scale monitoring system on settlement of super-large pile-group foundation in deep water was put forward. The reliable settlement results are obtained by means of multi-sensor data fusion. Finite element model of pile-group foundation is established. By analysis of finite element simulated calculation of pile-group foundation, rules of settlement and uneven settlement obtained by monitoring and calculation results are coincident and the absolute error of settlement between them is 4.7 mm. The research shows that it is reasonable and feasible to monitor settlement of pile-group foundation with the system, and it can provide a method for the same type pile-group foundation in deep water. © 2011 Central South University Press and Springer-Verlag Berlin Heidelberg. Source

Hong W.,Nanjing Southeast University | Wu Z.S.,Nanjing Southeast University | Yang C.Q.,Nanjing Southeast University | Wan C.F.,Nanjing Southeast University | And 2 more authors.
Journal of Sound and Vibration

A new condition assessment strategy of reinforced concrete (RC) beams is proposed in this paper. This strategy is based on frequency analysis of the dynamic data measured with distributed long-gage macro-stain sensors. After extracting modal macro-strain, the reference-based damage index is theoretically deducted in which the variations of modal flexural rigidity and modal neutral axis height are considered. The reference-free damage index is also presented for comparison. Both finite element simulation and experiment investigations were carried out to verify the proposed method. The manufacturing procedure of long-gage fiber Bragg grating (FBG) sensor chosen in the experiment is firstly presented, followed by an experimental study on the essential sensing properties of the long-gage macro-strain sensors and the results verify the excellent sensing properties, in particular the measurement accuracy and dynamic measuring capacity. Modal analysis results of a concrete beam show that the damage appearing in the beam can be well identified by the damage index while the vibration testing results of a RC beam show that the proposed method can not only capture small crack initiation but its propagation. It can be concluded that distributed long-gage dynamic macro-strain sensing technique has great potential for the condition assessment of RC structures subjected to dynamic loading. © 2012 Elsevier Ltd. All rights reserved. Source

Jia Y.-M.,Northeast Forestry University | Xu D.,Northeast Forestry University | Guo H.-Y.,Jiangsu Transportation Research Institute
Gongcheng Lixue/Engineering Mechanics

Based on the heat transfer theory, in the state of nature refrozen, the plane differential equation and initial boundary conditions of the temperature field of a pile foundation in a frozen soil region are presented considering hydrology-geology conditions and the initial ground temperature field and phase transformation effect. Taking the test pile engineering as an example, the numerical model of plane is established. The numerical results are in good agreement with the test results. The process of the refrozen both of the pile and frozen soil were analyzed. The conclusion is as follows: the distribution of temperature of the pile is asymmetry after casting, the change of temperature is nonlinear, and the core region of heat disturbance is ascertained. Source

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