scholarly journals Research on the Influence Mechanism of the High-Steep Slope on the Deformation Characteristics of Bridge Substructure

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yufang Zhang ◽  
Hongyu Liu ◽  
Jian Li ◽  
Jiaming Li ◽  
Qidi Huang ◽  
...  
Keyword(s):  
Pile Foundation ◽  
Lateral Displacement ◽  
Traction Force ◽  
Steep Slope ◽  
Bridge Pier ◽  
Deformation Characteristics ◽  
Bridge Structure ◽  
Influence Mechanism ◽  
Stress And Deformation ◽  
Bridge Pile Foundation

With the development of the Chinese railway, the high-steep slope is irreversible to be faced; especially under severe conditions such as heavy rainfall and earthquake, this kind of slope is prone to geological disasters, which seriously affects the safety and stability of the bridge substructure. Aiming to this, long-term monitorization and numerical analysis were carried out in this research, and the influence mechanism of the high-steep slopes on the stress and deformation characteristics of the bridge structure was studied. The research results show that under the effect of rainfall and earthquake, the original stress balance in the high-steep slope is broken, and the possibility of landslide thrust increases; under the comprehensive impact of residual landslide thrust, traction force at slope foot, vertical gravity of bridge slab and vehicle, and the bridge cap will deform. Besides, the deformation of the bridge pier exceeds the allowable lateral displacement of the top of the bridge pier, reaching 111.7%∼112.4% of the limit, which seriously affects the stability of the bridge structure and the safety of the railway service. Therefore, by increasing the support strength of the slope foot and the diameter of the bridge pile foundation, the traction force of the slope foot can be reduced, and the sliding resistance of the bridge pile foundation can be improved so as the safety of the bridge structure can be promoted.

scholarly journals Seismic Fragility Analysis of Bridge Group Pile Foundations considering Fluid-Pile-Soil Interaction

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Chao Zhang ◽  
Chengwang Wu ◽  
Piguang Wang
Keyword(s):  
Pile Foundation ◽  
Fragility Curves ◽  
Bridge Pier ◽  
Pile Foundations ◽  
Fragility Analysis ◽  
Seismic Fragility ◽  
Water Interaction ◽  
Bridge Group ◽  
Bridge Pile Foundation ◽  
Group Pile

The cross-sea bridges play an important role to promote the development of regional economy. These bridges located in earthquake-prone areas may be subjected to severe earthquakes during their lifetime. Group pile foundations have been widely used in cross-sea bridges due to their structural efficiency, ease of construction, and low cost. This paper investigates the seismic performance of bridge pile foundation based on the seismic fragility analysis. Based on the analysis platform OpenSees, the three-dimensional finite model of the bridge pile foundation is developed, where the pile-water interaction is replaced by the added mass method, nonlinear p-y, t-z, and q-z elements are used to simulate pile-soil interaction, and the displacement of the surface ground motion due to seismic excitations is applied on all spring supports. The seismic fragility curves of the bridge pile foundation are generated by using the earthquake records recommended by FEMA P695 as input motions. The curvature ductility based fragility curves are obtained using seismic responses for different peak ground accelerations. The effects of pile-water interaction, soil conditions, and different types of ground motions on the bridge pier fragilities are studied and discussed. Seismic fragility of the pier-group pile system shows that Sec C (the bottom section of the pier) is the most vulnerable section in the example fluid-structure-soil interaction (FSSI) system for all four damage LSs. The seismic responses of Sec E (a pile section located at the interface of the soil layer and water layer) are much lower than other sections. The parameter analysis shows that pile-water interaction has slight influence (less than 5%) on the fragility curves of the bridge pier. For the bridge group pile foundations considering the fluid-pile-soil interaction, PNF may induce larger seismic response than far-field (FF) and no-pulse near field (NNF). The bridge pile foundation in stiff soil is most vulnerable to seismic damage than soft condition.

scholarly journals Effects of Landslides on the Displacement of a Bridge Pile Group Located on a High and Steep Slope

2021 ◽  
Vol 2021 ◽  
pp. 1-29
Author(s):  
Y. F. Zhang ◽  
J. Li ◽  
W. Li ◽  
J. M. Li ◽  
H. Y. Liu
Keyword(s):  
Field Test ◽  
Pile Foundation ◽  
Load Transfer ◽  
Transfer Effect ◽  
Steep Slope ◽  
Pile Diameter ◽  
Bridge Foundation ◽  
Load Transfer Effect ◽  
Bridge Pile Foundation ◽  
High And Steep Slope

Engineering practice shows that the deformation of the slide-resistant pile may be transferred to the adjacent bridge foundation on an inclined slope, which can compromise the safety of the entire bridge. However, this phenomenon has rarely been considered in the past. To reveal the deformation transfer mechanism between the slide-resistant pile and the adjacent structures, a full-scale field test was performed on a high and steep slope located in a section of a certain railway. A numerical analysis model was constructed to simulate the field test and validate its parameters. Moreover, parametric analysis was also conducted to examine the influence of the pile length, pile diameter, and arrangement of the pile foundation. The results show that the bridge pile foundation is simultaneously affected by the “load transfer effect” caused by the slide-resistant pile and “traction effect” of the sliding slope. With the distance between the pile foundation and the slide-resistant pile increasing, the dominant factor affecting the deformation mode of the pile body is switched from the “load transfer effect” to the “traction effect.” Furthermore, a critical embedment depth exists for the bridge pile foundation built on a high and steep slope, which varies at different locations along the inclined stratum. In addition, using a pile arrangement with a larger pile diameter and lower number of piles is more beneficial for controlling the horizontal displacement of the bridge foundation. The results of the research provide a reference for the safety control of the engineering on the high and steep slope.

Mechanics Research on Rock Stress and Deformation of Lancang River Canyon's Large - Scale Dumping Deformation

2013 ◽  
Vol 353-356 ◽  
pp. 318-323
Author(s):  
Song Ye ◽  
Yu Sheng Li ◽  
Qian Guo
Keyword(s):  
Large Scale ◽  
Geological Structure ◽  
Deformation Characteristics ◽  
Deep Part ◽  
Trailing Edge ◽  
Geological Surveys ◽  
Depth Analysis ◽  
Numerical Simulation Methods ◽  
Complex Geological Structure ◽  
Stress And Deformation

This article is based on geological surveys combined with finite element and discrete element numerical simulation methods. In-depth analysis of the complex geological structure, deformation characteristics and stress - deformation problems of dumping rock, we clarify different deformation characteristics of deformable landslide inside, at the bottom and the deep part of trailing edge, and demonstrate the deformation will gradually shift from dumping to shear slip. Potential deformation failure mode will be dumped into the whole sliding - tension, which is controlled by the bottom broken belt, and potential deformation is mainly subject to the bottom fault F207-3 of deformed rock and the dumping broken belt at the deep part of trailing edge.

A brief discussion on the causes and treatment measures of bridge pile foundation defects

2015 ◽  
pp. 45-46
Author(s):  
Juan Li ◽  
Wenhong Ren ◽  
Jihong Wang ◽  
Zhao Zhang ◽  
Xiaohui He ◽  
...  
Keyword(s):  
Pile Foundation ◽  
Treatment Measures ◽  
Bridge Pile Foundation

scholarly journals Deformation Characteristics of Raising, Widening of Old Roadway on Soft Soil Foundation

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2117
Author(s):  
Keke Li ◽  
Wenyuan Xu ◽  
Liang Yang
Keyword(s):  
Lateral Displacement ◽  
Soft Soil ◽  
Ground Surface ◽  
Surface Settlement ◽  
Deformation Characteristics ◽  
Construction Methods ◽  
Ground Surface Settlement ◽  
Total Settlement ◽  
Soil Foundation ◽  
Soft Soil Foundation

The deformation characteristics of a raised and widened old Chinese roadway on a soft soil foundation are investigated in this study via finite element numerical simulation. The rules of ground surface settlement, slope foot lateral displacement, and ground surface settlement evolution of the roadbed under three modes (one-time construction of an eight-lane expressway, widened four-lane expressway, and raised/widened four-lane expressway) are compared. The ground surface settlement process of the eight-lane road foundation, which is formed by first widening and then raising the road, is highly complex. The ground surface settlement curve under the old road foundation increases and then decreases. The lateral displacement of the slope foot also interacts with the widening and raising of the eight-lane roadbed foundation. The range of lateral displacement is 70.05, 42.58, 124.81, 104.54 mm. Fifteen years after construction, the total settlement of the raised and widened roadbed is much larger than that of the one built directly. The total settlement values at the center of the two roadbeds are 297.05 and 234.85 mm, respectively. This manuscript provides data support for the reconstruction and expansion of roads on soft soil foundations, for choosing appropriate construction methods to build roads, and for avoiding major road damage, which is of great significance to the construction of road infrastructure in the future.

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