Zhou J.,Tongji University |
Shi D.-D.,Shanghai Maritime University |
Wu F.,Shandong Provincial Communications Planning and Design Institute |
Xue J.-F.,Monash University
Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering | Year: 2011
A modified CKC cyclic triaxial apparatus is used to monitor the evolution of granular soil microstructures during cyclic triaxial tests. Micro digital screening techniques are used to capture the change of microstructures of sand samples during liquefaction induced by cyclic loading. Digital images at certain stages of the tests are cut from the videos and further processed by self-developed software named GeoDIP. The microfabric evolutions including particle orientation, contact normal and number of contacts are analyzed. Labeled particles are traced to study the micro mechanism of soil deformation. It is found that there is no preferred orientation of the long axes of particles in liquefied samples. The main direction of contact normal between particles orients vertically whether the sample is liquefied or not. The samples experience a significant loss of contact number during liquefaction, but the number regains a lot after post-liquefaction drainage. Soil particles exhibit obvious translational motion before liquefaction, but start to move relatively and rotate when liquefaction occurs. The results of this study can not only explore the micro mechanism of sand liquefaction, but also provide an experimental basis for numerical modeling of sand liquefaction.
Gao F.,University of Jinan |
Xiong X.,Tongji University |
Zhang S.,Engineering Construction Standards Quota Station of Shandong Province |
Yuan H.,Shandong Provincial Communications Planning and Design Institute
Yingyong Jichu yu Gongcheng Kexue Xuebao/Journal of Basic Science and Engineering | Year: 2016
Based on the experimental study on prestressed steel reinforced concrete(PSRC)frame with steel in beams and column under vertical low cyclic reversed loading, the final failure mode, load-displacement hysteretic loops, displacement ductility and energy dissipation of PSRC frame beam were investigated. The results show that its failure patterns is“three hinge”failure mechanisms and load-displacement hysteretic loops are in plump-shape, and the frame beam has good ductility and energy dissipation capacity. The finite element analysis software ABAQUS was used to simulate the properties of specimens, the calculation results agreed with test results very well. Parametric analysis of the structure was carried out to study the impact on the skeleton curves of load-displacement and ductility of the PSRC frame beam. The concrete strength, ratio of encased steel, ratio of prestressing strength and ratio of the converted reinforcement were all considered as analysis parameters. The results show that ratio of prestressing strength, ratio of the converted reinforcement, the load-bearing capacity are improved with the increase of the concrete strength, but the ductility is lower, and the load-bearing capacity and the ductility are improved with the increment of ratio of encased steel. Based on the ductility analysis, some proposal are putted forward, which including ratio of encased steel is 4%~8%, ratio of prestressing strength is not greater than 6%and ratio of the converted reinforcement is not more than 3. 6%. Finally, the calculating method of displacement ductility coefficient was proposed and could provide reference for engineering design. © 2016, The Editorial Board of Journal of Basic Science and Engineering. All right reserved.
Liang X.,Shandong University of Technology |
Liang X.,Chang'an University |
Fu Y.,Shandong Provincial Communications Planning and Design Institute |
Xu Y.,Chang'an University
Advanced Materials Research | Year: 2011
Connected with the practical construction and considering Structural properties of single-tower self-anchored suspension bridge, the multi-level safety evaluation model is established according to the main risk factor and weighting rate of risk factor is analyzed by the analytic hierarchy process. A safety assessment method with qualitative analysis and quantitative analysis is proposed based on the grey theory and fuzzy mathematics theory for the practical problem of multi-index comprehensive evaluation, and risk ranking is given. © (2011) Trans Tech Publications.
Wang Y.L.,Chang'an University |
Wang Y.L.,Shandong Provincial Communications Planning and Design Institute |
Li C.,Shandong Jiaotong University
Advanced Materials Research | Year: 2014
Two level zone index system of the provincial highway geotechnical zone was established on the basis of analysis of the relationship between geotechnical elements and highway engineering. The highway rock-soil type conversion rules and the zone standard of two level zone indexes were set through comparative analysis of the characteristics of rock-soil on the engineering geological map. According to the general principles and methods of zone study, the research framework of provincial highway geotechnical zone was constructed. Under the guidance of this framework, Shandong province highway geotechnical zone was completed and the whole research area was divided into 2 grade I and 5 grade II. The results indicate that the new highway geotechnical zone can better reflect the variation of rock-soil engineering properties in Shandong province. The result verifies the scientificalness and effectiveness of the research framework of provincial highway geotechnical zone and provides basic data for research on highway geotechnical zone of nationwide. © (2014) Trans Tech Publications, Switzerland.
Zhou C.,Shandong Provincial Communications Planning and Design Institute
Key Engineering Materials | Year: 2016
As a new type of subgrade engineering filler, the cast-in-situ foamed lightweight soil has the advantages of light weight, good fluidity, stable performance, strong vertical stability, high strength and low environment impact. Five groups of monotonic and cyclic triaxial tests in the laboratory were carried out using GDS triaxial apparatus. The mechanical behaviour such as dynamic and static strength, dynamic and static modulus, hysteretic curve and failure characteristics of cast-in-situ foamed lightweight soil was studied. © 2016 Trans Tech Publications, Switzerland.
Zhou X.-Y.,Tongji University |
Zhang Y.-Q.,Tongji University |
Zhang Y.-Q.,Shandong Provincial Communications planning and Design Institute |
Gu M.,Tongji University
Gongcheng Lixue/Engineering Mechanics | Year: 2014
Sliding snow loads are an important component of snow loading on roofs. A simulation method for sliding snow loads is developed in this paper. Firstly, based on previously developed mass and energy balance models, a building roof snowmelt model is developed, which focuses on the features of the snowpack. Based on this model, it is proposed that the sufficient condition for roof snow sliding is that the liquid water in the snow exceeds the maximum water capacity of snow. Using the method for calculating sliding snow load proposed in the paper, simulations of the sliding snow loads on roofs in several representative areas in China are performed, and the influences from climate features and shielding effects of neighboring buildings are analyzed. At the same time the contributions of a variety of energies to snow sliding are presented quantitatively.
Li C.,Shandong Jiaotong University |
Wang Y.,Shandong Provincial Communications Planning and Design Institute
Advanced Materials Research | Year: 2013
The location technology of Truck Escape Ramp(TER) is the important guarantee for fully developing the TER actions and ensuring operation safety of heavy vehicles on long-steep downgrade. In order to improve the precision of TER location, this paper thoroughly analyzed the influence factors of TER location from the view of traffic accidents statistical data, road conditions and vehicle status. Expounded the theory of fuzzy rough set. Put forward the method of highway TER location based on fuzzy rough set. Used this method to evaluate the running safety of the unit sections on the long-steep downgrade. Calculated the comprehensive safety index values of sample sections and made ones with high comprehensive safety index values as the candidate sections for TER. Determined the accurate positions of the TER based on comparison of the comprehensive safety index value of adjacent candidate sections. Setting effect shows that the TER position determined by the method are scientific and rational. © (2013) Trans Tech Publications, Switzerland.
Chen A.,Shandong Jiaotong University |
Diao R.,Shandong Provincial Communications Planning and Design Institute
Applied Mechanics and Materials | Year: 2012
According to the basic principles and methods of the fuzzy reliability assessment to the existing bridge, RC rigid-frame arch bridge with Fuzzy reliability evaluation of a judgment factor sets of class I and class II are identified in this paper, aiming at the existing disease in this kind of bridge. Then, the fuzzy reliability comprehensive evaluation model of RC rigid-frame arch bridge is established. Meantime, the paper raises the membership function of each evaluation index; uses Analytic hierarchy process (AHP) to determine the weight vector of each factor. At last, a reliable practical analytical method for the evaluation of the existing RC rigid-frame arch bridge's bearing capacity is obtained. © (2012) Trans Tech Publications, Switzerland.
Meng Q.-S.,Ocean University of China |
Fan Y.-Q.,Ocean University of China |
Zhang K.,Shandong Provincial Communications Planning and Design Institute |
Zhang M.,Ocean University of China
Jilin Daxue Xuebao (Diqiu Kexue Ban)/Journal of Jilin University (Earth Science Edition) | Year: 2011
Making use of the tube wave detection method to find geological disasters, such as karsts or corrosion cracks within a certain range around the borehole, is a new means of engineering geophysical survey. To better understand the tube wave propagation mechanism in fluid-filled boreholes, a staggered-grid finite-difference approach is applied to compute the wave propagation in homogeneous isotropic media including a fluid-filled borehole. Firstly, the wave motion equation was introduced, and the finite-difference solution was obtained with Taylor's series expansion, and then, the stability and absorption boundary conditions were discussed. Using a homogenous isotropic model, the snapshots were calculated under the non-borehole conditions and borehole conditions respectively. Two models were designed for the seismology, one was a three-layered model containing a hole filled with soil, and another was a practical model designed according to field data. Numerical simulation results showed that tube wave reflections existed on the interface of different impedance, such as formation interfaces and karst boundaries; the difference of physical properties of strata had an influence on the amplitude and the frequency of reflection waves; and in the synthesis record, the intersection of reflection tube waves and direct tube waves is consistent with the actual boundaries of formation or anomalous bodies designed in the theoretical model.
Wang J.,Tongji University |
Bu L.,Shandong Provincial Communications Planning and Design Institute |
Cao C.,Tongji University
Journal of Bridge Engineering | Year: 2012
Four finite-element models of ships with deadweight tonnage varying from 3,000 to 50,000 t are developed for numerical collision simulation. The time histories of ship collisions against rigid walls are obtained using the software LS-DYNA. Equivalent static loading is determined, and simplified formulas are developed through a fitting procedure as indicated by the data from the numerical simulations. Codified formulations from AASHTO and other design specifications are compared with the simplified formulas. The geometric effects of the bridge foundation on the ship impact force are investigated with an example pile cap. A geometric modification factor is proposed for an ideal rectangular block to modify ship impact forces estimated by code formulas. © 2012 American Society of Civil Engineers.