scholarly journals Capacity of Cone-Shaped Hollow Flexible Reinforced Concrete Foundation (CHFRF) in Sand under Horizontal Loading

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Shanshan Li ◽  
Yukun Zhang ◽  
Dayong Li
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Wind Turbine ◽  
Earth Pressure ◽  
Ultimate State ◽  
Foundation Pit ◽  
Rubber Layer ◽  
Concrete Foundation ◽  
The Earth

The cone-shaped hollow flexible reinforced concrete foundation (CHFRF) is an innovative type of mountain wind turbine foundation, which outperforms the regular mountain wind turbine foundation in reducing the steel and concrete and protecting the surrounding vegetation for the cavity absorbs soil obtained from excavating the foundation pit. Moreover, the rubber layer installed between the wall of CHFRF and the surrounding ground increases foundation flexibility and releases the larger overturning moment induced by wind. The rubber layer is made of alternately laminated rubber and steel. The objectives of this research are to study the lateral bearing behaviors of the CHFRF under monotonic and cyclic lateral loading in sand by model tests and FEM simulations. The results reveal that the CHFRF rotates during loading; and, in the ultimate state, the rotation center is located at a depth of approximately 0.6–0.65 times the foundation height and is 0.15–0.18 times the diameter of the foundation away from its centerline as well. The lateral bearing capacity of the CHFRF improves with the increase of embedded depth and vertical load applied to the foundation. Moreover, compared to the CHFRF without the rubber layer, the rubber layer can reduce the earth pressure along the wall of CHFRF by 22% and decrease the deformed range of the soil surrounding the foundation, revealing that it can reduce the loads transferred to the surrounding soil for extending the service life of the foundation. However, the thickness and stiffness of the rubber layer are important factors influencing the lateral bearing capacity and the energy dissipation of the foundation. Moreover, it should be noted that the energy dissipation mainly comes from the steel of the rubber layer rather than rubber.

Experimental Study on Earth Pressure of Corrugated Steel Culvert under High Fill Embankment

2013 ◽  
Vol 405-408 ◽  
pp. 1815-1819
Author(s):  
Wen Sheng Yu ◽  
Zhu Long Li ◽  
Xiao Ru Xie ◽  
Li Yuan Guo
Keyword(s):  
Mechanical Property ◽  
Experimental Study ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Earth Pressure ◽  
Reinforced Concrete Slab ◽  
The Earth ◽  
Filling Height ◽  
Test Points ◽  
Better Than

To analyze the earth pressure of corrugated steel culvert under high fill embankment, a field test was taken and the change law was got with the filling height increasing, the force state when geotechnical grilles were laid on the top of corrugated steel culvert was compared to that of reinforced concrete slab culvert. Results show that the pressure on the top of corrugated steel culvert is smaller than that on the external in same level when test points are near to culvert, the values of test points above and below geotechnical grilles are close, and the pressure of corrugated steel culvert is smaller than that of reinforced concrete slab culvert when filling height is above 7.3 m. So analysis indicates corrugated steel culvert spreads the upper load better, the geotechnical grille can reduce the pressure effectively through earth pressure redistribution, and the mechanical property of corrugated steel culvert is better than reinforced concrete slab culvert under high fill embankment.

scholarly journals An Experimental Study on the Ecological Support Model of Dentate Row Piles

2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Yousheng Deng ◽  
Zhihe Cheng ◽  
Mengzhen Cai ◽  
Yani Sun ◽  
Chengpu Peng
Keyword(s):  
Building Materials ◽  
Soft Soil ◽  
Earth Pressure ◽  
Shallow Foundation ◽  
Laboratory Model ◽  
Foundation Pit ◽  
Maximum Displacement ◽  
Single Row ◽  
The Earth ◽  
Soil Foundation

Bamboo is highly renewable and biodegradable with good short-term strength, which meets the requirement for temporal support structures in shallow foundation pits. Based on this, we conducted a laboratory model test on the dentate bamboo micropile support structure combined with environmentally friendly building materials and new type of piles, to explore the stress characteristics, stress change regularity, and the support effect of the system in soft soil foundation pits. The results show that the earth pressure on the pile sides above the excavation surface gradually decreases with an increase in the excavation depth. The bending deformation of the bamboo pile was also significant. The results also show that the earth pressure and the pile strain below the excavation surface change slightly during the excavation process. When the short sides of the foundation pit were loaded, the highest strain was recorded in the piles 4 and 11. A maximum strain of 358.93 με was recorded, and the maximum displacement of the pile in the top part was obtained to be only 2.14 mm. The most subsidence of dentate pile obtained is only 1.88 mm, whereas that of the single-row pile is 2.35 mm. Compared to the traditional single-row pile, the dentate piles can effectively reduce the horizontal deformation as well as the surface subsidence effectively. They can also support more external lateral load, and hence maintain the foundation stability and give better support. The results provide a theoretical basis for ecological bamboo support technology and have great value to be promoted.

Experimental Study on Seismic Performance of the Reinforced Concrete Grid-Mesh Frame Wall

2013 ◽  
Vol 680 ◽  
pp. 234-238
Author(s):  
Jin Li Qiao ◽  
Wen Ling Tian ◽  
Ming Jie Zhou ◽  
Fang Lu Jiang ◽  
Kun Zhao
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Seismic Performance ◽  
Seismic Energy ◽  
Width Ratio ◽  
Filling Material ◽  
Energy Dissipation Capacity ◽  
Grid Mesh

In order to validate the seismic performance of reinforced concrete grid-mesh frame wall , four grid frame walls in half size is made with different height-width ratios and different grid forms in the paper. Two of them are filling with cast-in-place plaster as filling material. According to the experimental results of these four walls subjected to horizontal reciprocating loads, we know that the grid-mesh frame wall's breaking form are in stages and multiple modes, and the main influencing factors are height-width ratio and grid form, what's more, with cast-in-place plaster as fill material, could not only improve the level of the wall bearing capacity and stiffness, but also improve the ductility and seismic energy dissipation capacity.

scholarly journals Correction of Earth Pressure and Analysis of Deformation for Double-Row Piles in Foundation Excavation in Changchun of China

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Yijun Zhou ◽  
Aijun Yao ◽  
Haobo Li ◽  
Xuan Zheng
Keyword(s):  
Physical Model ◽  
Model Test ◽  
Large Scale ◽  
Similarity Theory ◽  
Earth Pressure ◽  
Physical Model Test ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Double Row ◽  
The Earth

In order to study the earth pressure and the deformation behavior of the double-row piles in foundation excavation, a large-scale physical model test was introduced to simulate deformation of double-row piles in foundation excavation based on the principle of similarity theory in this paper. Represented by the deep foundation pit engineering of Changchun, the strain and the displacement of the double-row piles and the earth pressure are calculated by the above-mentioned physical model test. Then a numerical simulation has been carried out to validate practicability of the physical model test. The results show that the strain and the displacement of the front-row piles are larger than the back-row piles. The earth pressure of the front-row piles appears to be “right convex,” correcting the specification of the earth pressure and putting forward the coefficient of β. The results in this paper may provide constructive reference for practical engineering.

scholarly journals Analysis of Situ Test Results of Earth Pressure and Pile Internal Force under Pile-Anchor Support in a Deep Foundation Pit in Xi’an

2022 ◽  
Vol 2148 (1) ◽  
pp. 012051
Author(s):  
Ruibin Yang ◽  
Xinsheng Li ◽  
Dongzhou Xie ◽  
Hongte Meng
Keyword(s):  
Earth Pressure ◽  
Internal Force ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Support Design ◽  
Limiting State ◽  
Obvious Effect ◽  
Deep Foundation Pit ◽  
The Earth ◽  
Monitoring Test

Abstract At present, in deep foundation pit engineering, on the one hand, practice is ahead of theory, and on the other hand, theory can not correctly reflect the actual construction process and environmental effects. In order to further study the distribution and change law of earth pressure and internal force of pile body in deep foundation pit pile-anchor supporting system, field monitoring test of earth pressure and pile body reinforcement stress was carried out. The monitoring results show that before excavation, the distribution of earth pressure has a great relationship with the layering of the soil, and it is distributed in sections along the depth. Compared with the theoretical static earth pressure, the measured data of the upper depth is relatively small; after excavation, the overall earth pressure is distributed along the depth in a “z” shape under the non-limiting state. As the excavation progresses, the magnitude of the reduction of the earth pressure varies from place to place, and the magnitude of the decrease of the soil with better properties is not large; after the excavation, the stress and earth pressure of the pile reinforcement correspond to each other, and the distribution is also nonlinear. The existence of anchor tension has an obvious effect on improving the internal force of the pile. The selected earth pressure calculation methods have some discrepancies in the calculation of the earth pressure value of the project, and they need to be further improved. The research in this paper can provide reference and reference for the calculation of earth pressure and support design of pile-anchor supported foundation pit.

scholarly journals Influence of Different Types of Infill Walls on the Hysteretic Performance of Reinforced Concrete Frames

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 310
Author(s):  
Fei Wang ◽  
Kaozhong Zhao ◽  
Jianwei Zhang ◽  
Kai Yan
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Frame Structure ◽  
Concrete Frames ◽  
Reinforced Concrete Frame ◽  
Infill Walls ◽  
Concrete Frame ◽  
Hysteretic Performance ◽  
Energy Dissipation Capacity

To study the influence of masonry infill walls on the hysteretic performance of reinforced concrete frames, a cyclic experiment was conducted for three two-story and two-span reinforced concrete frame structures, including one reinforced concrete frame without infill walls and two frames with infill walls. Whether the infill walls were constructed in the frames and the type of infilled material were the main parameters of the test. The major results reveal that: the infill walls clearly changed the mechanical mechanism of the frame structure at the early stage of loading, magnified the stiffness and horizontal bearing capacity of the frame structure, and enhanced the energy dissipation capacity of the frame structure, but reduced the deformation performance of the frame structure. In the later stage of loading, the infill walls would no longer work as one with the frame gradually with the failure of the infill walls, and the above performance of the structure would approach the empty frame structure. Moreover, the initial stiffness, energy dissipation capacity, and horizontal bearing capacity of the frame with infill walls of clay hollow bricks were the highest among the three specimens. But due to the strong diagonal bracing effect, the damage to the top of the columns and beam-column joints was serious, the yield displacement was reduced significantly, and the shear failure of the top of the columns and the joints occurred prematurely, which showed poor performance of deformation and ductility. However, the frame with infill walls of relatively soft aerated lightweight concrete blocks showed better performance of deformation and ductility.

Analyses of Earth Pressure on Gridding Concrete Retaining Wall in the Excavation of Deep Foundation Pit in Soft Soil Area

2011 ◽  
Vol 52-54 ◽  
pp. 2181-2186
Author(s):  
Guang Zhu Zhou ◽  
Xu Wei ◽  
Chen Yu
Keyword(s):  
Retaining Wall ◽  
Soft Soil ◽  
Earth Pressure ◽  
Front Wall ◽  
Three Dimension ◽  
Deep Foundation ◽  
Foundation Pit ◽  
Finite Element Software ◽  
The Earth ◽  
Practical Engineering

This paper is mainly to study earth pressure on Gcrw used as a new kind of supporting structures in the excavation of deep foundation pits in soft soil region. On the basis of the simulation of step by step excavation by using big finite element software Abaqus/CAE and considering three-dimension elastoplastic stress state, the characteristics of different earth pressure are systematically discussed upon practical engineering. By comparing simulation results with calculated results based on calculation formula of Rankine Theory, it can be seen that the earth pressure in active zone is different from theoretic active earth pressure and earth pressure at rest while walls and soil in the gridding are regarded as a whole, which is greater than the former and somewhere similar to the latter, the earth pressure in passive zone is bigger than theoretic value of passive earth pressure, it is the tensive force from partition wall that prevent the front wall from overturning. These conclusions will be helpful for design and construction of new retaining wall.

scholarly journals Seismic Behavior of RC Bridge Piers Locally Replaced with SFRC-FA Subjected to Torsion Combined with Axial Compression

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Jiyang Wang ◽  
Yongjun Wang ◽  
Chenglin Wan ◽  
Rongda Chen ◽  
Chengbin Liu ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Energy Dissipation ◽  
Bearing Capacity ◽  
Seismic Behavior ◽  
Plastic Hinge ◽  
Fiber Reinforced Concrete ◽  
Hinge Region ◽  
Fine Aggregate ◽  
Steel Fiber Reinforced Concrete ◽  
Conventional Concrete

Under complex seismic forces, the failure characteristics of the plastic hinge region at the bottom of the pier column and the methods improving the ductility have attracted extensive attention. In this study, steel fiber-reinforced concrete with fine aggregate (SFRC-FA) was applied to locally replace the conventional concrete in the potential plastic hinge region at the bottom of the pier column. Five SFRC-FA pier column specimens with different stirrup ratios and different replacement lengths and one conventional reinforced concrete pier column specimen were produced. Using the seismic behavior tests under the combined bending-shear-torsion-axial force, the failure mode, torsional bearing capacity, energy dissipation, and the torsional plastic hinges of the pier columns were investigated. In addition, an equation for calculating the torsional bearing capacity of the new composite pier columns was proposed. The results showed that (1) compared with the reinforced concrete pier column, the plastic hinge was shifted from the bottom of the pier column to the middle of the height of the pier column due to the application of SFRC-FA at the bottom of the pier column, which improved the torsional bearing capacity; (2) the effect of reducing the stirrup ratio of the SFRC-FA replacement region on the torsional bearing capacity, cracking mode, energy dissipation, and ductility was not obvious; (3) the accuracy of the new equation based on the space truss model proposed in this article was verified by comparison with the experiments of this study and other researches.

scholarly journals Field Monitoring and Numerical Analysis of the Reinforced Concrete Foundation of a Large-Scale Wind Turbine

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yanming Zhou ◽  
Xinxi Liu ◽  
Zongwei Deng ◽  
Qian-Feng Gao
Keyword(s):  
Reinforced Concrete ◽  
Wind Turbine ◽  
Large Scale ◽  
Dynamic Contact ◽  
Shallow Foundation ◽  
Foundation Design ◽  
Onshore Wind ◽  
Concrete Foundation ◽  
Operation Phase ◽  
Contact Pressures

The objective of this study is to examine the performance of the shallow reinforced concrete foundation of a large-scale wind turbine under the influence of environmental loads. A 2 MW horizontal-axis onshore wind turbine supported by a shallow concrete foundation was considered. The foundation stresses, foundation settlements, and static and dynamic contact pressures at various positions of the shallow foundation were monitored from the construction phase to the operation phase in the field. Numerical simulations were also performed to further analyze the behavior of the wind turbine foundation in different cases. The results demonstrate that the responses of the reinforced concrete foundation, i.e., foundation stresses, contact pressures, and foundation settlements, were variables closely related to the wind direction and wind speed. The distribution of foundation stresses suggested that a reasonable design of steel reinforcement cages around the foundation steel ring is important. The dynamic contact pressure of the foundation could reach 5 kPa, so the influence of dynamic wind loads on the foundation response could not be always neglected, particularly for the foundations seated on weak soils. The foundation settlement during the operation phase could be characterized by the logistic model, but its distribution was uneven due to the presence of eccentric upper weight and wind load. The findings would provide guidance for the foundation design of onshore wind turbines in hilly areas.

The Calculation of Incremental Method Based on Earth Pressure Modification

2012 ◽  
Vol 256-259 ◽  
pp. 507-513
Author(s):  
Shou Ze Cheng ◽  
Wei Hua Wang ◽  
Chang Jie Xu
Keyword(s):  
Earth Pressure ◽  
Structure Design ◽  
Practical Calculation ◽  
Foundation Pit ◽  
Retaining Structure ◽  
Incremental Method ◽  
The Earth ◽  
Calculation Results ◽  
Practical Engineering ◽  
Incremental Step

Incremental method, as one of the practical calculation methods in retaining structure design of foundation pit, has been widely used. When incremental method is applied, the earth pressure, acting on the retaining structure on each incremental step, is considered as static earth pressure. Actually, the state of earth pressure changes constantly with the increase of soil displacement in the process of excavation. This paper introduces the relation of displacement and earth pressure based on the soil stress-strain state, and makes corrections for the earth pressure of the incremental method. By comparing with the measured data of the engineering, the calculation results, which consider earth pressure modification, are in good line with the practical engineering condition. The method in this paper can provide certain reference for related engineering design.

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