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.

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 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.

Study on Effect of Excavation Depth on Internal Force of Retaining Structure of Arc Row Piles with Arc Ring Beam on the Pile Top

2014 ◽  
Vol 919-921 ◽  
pp. 762-768
Author(s):  
Zhi Wei Zhang ◽  
Rong Gui Deng ◽  
Ze Shuo Chen
Keyword(s):  
Internal Force ◽  
Calculation Model ◽  
Structure Calculation ◽  
Foundation Pit ◽  
Engineering Research ◽  
Retaining Structure ◽  
Body Distribution ◽  
Practical Engineering ◽  
Set Up ◽  
Deformation Compatibility

In order to control deformation of foundation pit effectively and guarantee safety of building around, utilizing the stress characteristics of arch, use the new spatial retaining structure of arc row piles with arc ring beam on the pile top. The arc ring beam can provide constraint to pile top, so internal force of pile body distribution is uniform, and improve the integrity stability of piles. The ring beam with compression mainly can give use of high compression capability of concrete. According to the high order statically indeterminate characteristics of the retaining structure, calculation model of ring beam and pile respectively is established by the redundant forces between beam and pile top. By using deformation compatibility to set up flexibility equation of the retaining structure, and solve the redundant forces, then calculate the internal force and displacement of ring beam and piles. Through calculating the practical engineering, research the effect of excavation depth on internal force and displacement of piles and the arc ring beam on the pile top.

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 Study on the earth pressure of a foundation pit adjacent to a composite foundation with rigid-flexible and long-short piles

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251985
Author(s):  
Yuancheng Guo ◽  
Shaochuang Gu ◽  
Junwei Jin ◽  
Mingyu Li
Keyword(s):  
Three Dimensional ◽  
Earth Pressure ◽  
Friction Angle ◽  
Element Model ◽  
Composite Foundation ◽  
Deep Soil ◽  
Foundation Pit ◽  
Testing Procedures ◽  
Retaining Structure ◽  
Lateral Earth Pressure

Model tests were performed to investigate the lateral earth pressure acting on the retaining structure adjacent to both natural ground (NG) and composite foundation (CFRLP), which were supported with rigid-flexible and long-short piles. Two testing procedures, namely, applying a load to the foundation and rotating the retaining structure along its toe, were considered. The results indicate that the additional lateral earth pressure acting on the retaining structure adjacent to the CFRLP is less than that of the NG in the depth of the reinforcement area strengthened by flexible piles. Compared with NG, the CFRLP yielded a smaller normalized height of application of the lateral earth pressure, suggesting that the CFRLP blocked the horizontal diffusion of the load and had a strong ability to transfer the surcharge load to the deep soil. When rotating the retaining structure, the lateral earth pressure acting on the upper part of the retaining structure experienced limited reduction once the displacement at the top of the retaining structure was greater than 8 mm, whereas the pressure acting on the lower part of the retaining structure continued to decrease with increasing displacement. In addition, a three-dimensional finite element model (FEM) was used to investigate the influence of the pile parameter and the wall-soil friction angle on the additional lateral earth pressure.

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.

The Numericial Calculation of Retaining Structure with Double-Piles

2014 ◽  
Vol 530-531 ◽  
pp. 928-931 ◽  
Author(s):  
Ying Hui Chen ◽  
Yan Lian Pan
Keyword(s):  
Numerical Simulation ◽  
Finite Difference ◽  
Engineering Model ◽  
Foundation Pit ◽  
Double Row ◽  
Retaining Structure ◽  
Calculation Results

Combined with a foundation pit in kunming, the paper use the finite-difference software flac3d to establish engineering model and carry on the numerical simulation to simulate the excavation on the initial engineering condition of the double-row piles retaining structure. Summarize the calculation results when change the distance of the pile-rows and the length of the piles to analyze the results differences and changing law. The conclusion has some practical value in engineering.

A Study on the Earth Pressure of Top Culvert of High Embankment

2012 ◽  
Vol 178-181 ◽  
pp. 1104-1111 ◽  
Author(s):  
Shi Sheng Zhou ◽  
Xi Meng Sun ◽  
Jun Peng ◽  
Jia Lv
Keyword(s):  
Finite Element ◽  
Earth Pressure ◽  
Structure Design ◽  
Actual Condition ◽  
Test Model ◽  
Actual Situation ◽  
Theoretical Derivation ◽  
Finite Element Software ◽  
The Earth ◽  
Element Simulation

Based on the extensive research and analysis of actual condition of top culvert of high embankment, a calculation theory for the earth pressure of top culvert was presented. The theory could optimize the structure design for culverts, and reduce the waste of resource. First, based on the simplified assumption of the stress of soil on the top culvert and the analysis of single unit of the load on the top culvert, the calculation formula of earth pressure on different position of top culvert was presented by theoretical derivation. Then, to verified the results by using scaled test model and ABAQUS finite element software. Through the comparison with the traditional calculation theory and finite element simulation, we could prove that the calculation theory is more tallies with the actual situation of the earth pressure on the top culvert.

scholarly journals Back analysis of pile and anchor retaining structure based on BOTDA distributed optical fiber sensing technology

2021 ◽  
Vol 248 ◽  
pp. 01036
Author(s):  
Xin Wang ◽  
Xie Hui Luo ◽  
Wan xue Long ◽  
Bo Jiang
Keyword(s):  
Earth Pressure ◽  
Internal Force ◽  
Force Distribution ◽  
Foundation Pit ◽  
Retaining Structure ◽  
Fiber Sensing ◽  
Sensing Technology ◽  
Optical Fiber Sensing ◽  
Anchor Structure ◽  
Distributed Optical Fiber

In order to understand the deformation law and internal force distribution characteristics of the pile-anchor retaining structure in deep foundation pit engineering, the stress of the pile-anchor retaining system in the process of foundation pit excavation was tested by using the distributed optical fiber sensing technology of BOTDA. It uses the supporting pile cloth to set up the strain cable to collect the strain from the excavation process to the stability of the foundation pit, which analyzes the stress and internal force distribution. The results show that the overall deformation of the foundation pit is small and in a stable state. It uses the monitoring strain energy to truly reflect the distribution and transmission law of the pile internal force. It is shown that the bending moment is the maximum at the action position of the anchor cable on the pile anchor structure and 2.5m below the bottom of the pit. The design needs to reinforce the construction of such locations. At the same time, the distribution form of earth pressure calculated in reverse is different from the conventional one. When there are multiple rows of prestressed anchor cables, the earth pressure applied on the support is less than the calculated value of classical earth pressure theory. This pile anchor structure design theory and engineering application has reference value.

The Relationship between Retaining Wall Deformation and Earth Pressure in Deep Excavation

2012 ◽  
Vol 446-449 ◽  
pp. 1690-1695
Author(s):  
She Qin Peng ◽  
Qi Hua Zhao ◽  
Zi Yang Chen
Keyword(s):  
Retaining Wall ◽  
Earth Pressure ◽  
Suspension Bridge ◽  
Deep Excavation ◽  
Foundation Pit ◽  
Retaining Structure ◽  
Pressure Calculation ◽  
Wall Deformation ◽  
Pit Depth ◽  
The Relationship

Earth pressure may change with retaining wall deformation in the process of deep excavating. But how? The answer can be very important to the safety of retaining system. Using monitoring data of north anchor foundation pit of Runyang suspension bridge, this paper studied retaining structure and soil interaction. Find the relationship between retaining wall deformation and earth pressure in deep excavation. In this case, earth pressure increased with wall deformation upward the depth of 18m and decreased with wall deformation down below. A regression equation about foundation pit depth and ratio of earth pressure and wall deformation was established. Then give a simplified earth pressure calculation method considering retaining wall deformation.

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