scholarly journals Cause Analysis and Countermeasures of Through Shakes in Foamed Concrete Subgrade

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xianbin Huang ◽  
Chenyang Liu ◽  
Yahong Wangren ◽  
Mingxing Wang ◽  
Yujiao Mei ◽  
...  

The paper presents a new type of material—foamed concrete—adopted for expansion subgrade of the expressway. Intriguingly, the irregular through shakes appear on its top. The method combining the engineering case, theoretical analysis, and numerical simulation is employed to analyze its T-shaped and tree-shaped through shake. The research indicates that when the underground water table is high, cracks are easily seen on the top of step-shape foamed concrete due to buoyancy force. Under the concentrated load effect, the maximum displacement of 27.09 mm is observed on the top of the simply supported beam when elastic modulus is 200 MPa. The maximum principle tensile stress of 0.34 MPa also occurs on the top of the simply supported beam when elastic modulus is 200 MPa and 400 MPa, which is greater than tensile strength of foamed concrete of 0.31 MPa and 0.26 MPa at 7 d and 28 d, respectively. Thus, the adoption of a simply supported beam structure fits site through crack. To avert cracks on the top of foamed concrete in high groundwater table, the antibuoyancy measures should be adopted prior to construction of the upper bearing stratum. The study has expanded the application scope of subgrade and enriched theory of foamed concrete filled in high groundwater table, providing a significant reference to similar projects.

Author(s):  
Zhenghao Yang ◽  
Erkan Oterkus ◽  
Selda Oterkus

Abstract In this study, a novel higher-order peridynamic beam formulation is presented. The formulation is obtained by using Euler-Lagrange equations and Taylor’s expansion. To demonstrate the capability of the presented approach, several different beam configurations are considered including simply supported beam subjected to distributed loading, simply supported beam with concentrated load, clamped-clamped beam subjected to distributed loading, cantilever beam subjected to a point load at its free end and cantilever beam subjected to a moment at its free end. Transverse displacement results along the beam obtained from peridynamics and finite element method are compared with each other and very good agreement is obtained between the two approaches.


2013 ◽  
Vol 671-674 ◽  
pp. 1362-1366
Author(s):  
Peng He ◽  
Sheng Jin Ge ◽  
Min Gang Zhai

Monte-Carlo was applied to generate random traffic flow after frequent, moderate and rare earthquake respectively based on sample of vehicle investigation in“907”Zhaotong, Yiliang earthquake (2012), Yunnan province, considering vehicle parameters, such as types, driving, distance, ratio in earthquake-relief campaign. Vehicle load effect was analyzed for different spans of Simply Supported Beam Bridge, then characteristic value of lane loading which ruled by 《General Code Designs of Highway Bridges and Culverts(JTG D60-04)》(China) was revised. Research can not only provide standard for rapid estimate and repair of bridge after earthquake, but also give theoretical basis for revising anti-seismic codes or guidelines in China.


1957 ◽  
Vol 24 (3) ◽  
pp. 453-456
Author(s):  
P. G. Hodge

Abstract Interaction curves are presented for plastic beams subject to combined shear and bending. A general formula is obtained and specific curves are drawn for rectangular and I-sections. A simply supported beam with a concentrated load is considered as an example. The results are compared with those of simple beam theory and with available plane-stress solutions. It is concluded that the elementary theory is adequate for height-to-length ratios of less than 0.1, while the present theory is useful in the range from 0.1 to 1.0.


2014 ◽  
Vol 556-562 ◽  
pp. 751-754 ◽  
Author(s):  
Xiao Ping Wang ◽  
Ming Shui Li

In this paper, The vertical vibration’s analytical expression of Euler-Bernoulli beam traveled by moving loads is used to analyze the effect factors such as vehicle speed and damping ratio. The calculating program is made with MATLAB to analyze the dynamic response of a bridge as an illustrative example. A 32 meters simply supported beam traversed by moving loads of 8 ICE3 motor cars is analyzed. The calculation results show that the maximum displacement of the bridge appears at or near the mid-span and it has nothing to do with the position of the loads. The dynamic amplification coefficient of displacement at mid-span is not linearly increased with the vehicle speed improving. The damping ratio can decrease the dynamic response of the bridge dramatically, especially at the resonance speed.


Author(s):  
Gonglian Dai ◽  
Meng Wang ◽  
Tianliang Zhao ◽  
Wenshuo Liu

<p>At present, Chinese high-speed railway operating mileage has exceeded 20 thousand km, and the proportion of the bridge is nearly 50%. Moreover, high-speed railway design speed is constantly improving. Therefore, controlling the deformation of the bridge structure strictly is particularly important to train speed-up as well as to ensure the smoothness of the line. This paper, based on the field test, shows the vertical and transverse absolute displacements of bridge structure by field collection. What’s more, resonance speed and dynamic coefficient of bridge were studied. The results show that: the horizontal and vertical stiffness of the bridge can meet the requirements of <b>Chinese “high-speed railway design specification” (HRDS)</b>, and the structure design can be optimized. However, the dynamic coefficient may be greater than the specification suggested value. And the simply supported beam with CRTSII ballastless track has second-order vertical resonance velocity 306km/h and third-order transverse resonance velocity 312km/h by test results, which are all coincide with the theoretical resonance velocity.</p>


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