scholarly journals Vertical Bearing Capacity of Precast Pier Foundation Filled with Demolished Concrete Lumps

2021 ◽  
Author(s):  
Bin Lei ◽  
Wengui Li ◽  
Zhuo Tang ◽  
Fuzhi Yang
Keyword(s):  
Bearing Capacity ◽  
Shear Failure ◽  
Load Transfer ◽  
Precast Concrete ◽  
Utilization Efficiency ◽  
Soil System ◽  
Ordinary Concrete ◽  
Local Shear ◽  
S Curve ◽  
Vertical Bearing

The application of recycled compound concrete made of demolished concrete lumps (DCLs) and fresh normal concrete in pier foundation can effectively improve the utilization efficiency of construction waste resources. In this study, two prefabricated pier foundations based on recycled compound concrete (dimension of Ø800 × 2500 mm and Ø1000 × 2500 mm) and two cast-in-place pier foundations based on ordinary concrete (dimension of Ø800 × 2500 mm and Ø1000 × 2500 mm) were tested. Special attention was devoted to the load-settlement curve characteristics of the precast pier foundation of compound concrete, the load transfer law of the pier-soil system, the soil pressure distribution at the bottom of the pier, and the failure mode. The results showed that the Q-S curve of precast concrete pier foundation made of recycled compound concrete is slow deformation at loading, which is consistent with that of cast-in-place concrete pier foundation. The load transfer theory of pier-soil system is established, and its accuracy is verified by experimental analysis. The precast foundation of recycled compound concrete is the same as the cast-in-place foundation of ordinary concrete. The failure form of prefabricated pier foundation made of recycled compound concrete was a local shear failure, while the failure form of ordinary concrete cast-in-place pier foundation was piercing-type shear failure. The feasibility of relevant theoretical methods for calculating the vertical ultimate bearing capacity is examined.

Analysis of an O-Cell Pile Test in Jinan with FEM

2012 ◽  
Vol 170-173 ◽  
pp. 33-36
Author(s):  
Ying Jie Zheng ◽  
Xue Dai ◽  
Lian Xiang Li
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
Ultimate Bearing Capacity ◽  
Soil System ◽  
Pile Test ◽  
Load Displacement ◽  
S Curve ◽  
Transfer Method ◽  
Load Transfer Method

In order to promote the experience of applying O-cell pile test to determine the behaviors of integral pile in Jinan, a case of O-cell pile test in Jinan was analyzed with proposed approach. The pile-soil system was simulated with FEM. The resistance parameters of piles, the load-displacement curves and the ultimate bearing capacity of integral pile were determined. Comparing with results obtained from load transfer method, it is found that the p-s curve of integral pile obtained from load transfer method is conservative.

A numerical approach to predict soil bearing potential for isolated footing

2021 ◽  
Author(s):  
Gilbert Hinge ◽  
Jayanta Kumar Das ◽  
Biswadeep Bharali
Keyword(s):  
Bearing Capacity ◽  
Shear Failure ◽  
Correlation Coefficients ◽  
Failure Criteria ◽  
Numerical Approach ◽  
Ultimate Bearing Capacity ◽  
Foundation Design ◽  
Advantages And Disadvantages ◽  
Local Shear ◽  
Failure Conditions

<p>The success of any civil engineering structure's foundation design depends upon the accuracy of estimation of soil’s ultimate bearing capacity. Numerous numerical approaches have been proposed to estimate the foundation's bearing capacity value to avoid repetitive and expensive experimental work. All these models have their advantages and disadvantages. In this study, we compiled all the governing equations mentioned in Bureau of Indian standard IS:6403-1981 and modify the equation for Ultimate Bearing Capacity. The equation was modified by considering two new parameters, K1(for general shear) and K2 (for local shear) so that a common governing equation can be used for both general and local shear failure criteria. The program used for running the model was written in MATLAB language code and verified with the observed field data. Results indicate that the proposed model accurately characterized the ultimate, safe, and allowable bearing capacity of a shallow footing at different depths. The correlation coefficients between the observed and model-predicted bearing capacity values for a 2m foundation depth with footing size of 1.5 ×1.5, 2.0 × 2.0, and 2.5 × 2.5 m are 0.95, 0.94, and 0.96. A similar result was noted for the other foundation depth and footing size. Findings show that the model can be used as a reliable tool for predicting the bearing capacity of shallow foundations at any given depth.  Moreover, the formulated model can also be used for the transition zone between general and local shear failure conditions.</p>

The Experiment on how the Ratio of Diameter to Height D/H Influences the Bearing Capacity of Bucket Foundation

2014 ◽  
Vol 488-489 ◽  
pp. 629-634
Author(s):  
Shuai Liu ◽  
Wen Bai Liu ◽  
Liang Yang
Keyword(s):  
Bearing Capacity ◽  
Ultimate Strength ◽  
Bucket Foundation ◽  
S Curve ◽  
Vertical Bearing ◽  
Room Model ◽  
The Cost ◽  
Vertical Bearing Capacity ◽  
Maximum Utilization ◽  
Ultimate Displacement

Through eight groups of room model experiments based on bucket foundation, P-S curve can be plotted for each group according to the experiments results and be able to get the ultimate strength and ultimate displacement for them. Therefore how the ratio of the ultimate vertical bearing capacity and the ultimate displacement changes with the ratio of diameter to height can be analyzed. When the ratio of diameter to height is less than 1.2, the ratio of the ultimate vertical bearing capacity and the ultimate displacement changes significantly; and when the ratio of diameter to height is greater than 1.2, the ratio of ultimate vertical bearing capacity and ultimate displacement is not affected obviously. When the ratio of diameter to height is 1.2, it reaches the maximum utilization of the materials, and the cost of the project can be effectively reduced. So the paper considers that the ratio of diameter to height = 1.2 can be used as the optimum point of the ratio of diameter to height of the bucket foundation.

Experimental Investigations on the Seismic Behavior of Precast Concrete Columns with Novel Box Connections

2019 ◽  
Vol 14 (02) ◽  
pp. 2050007
Author(s):  
Xizhi Zhang ◽  
Shengbo Xu ◽  
Shaohua Zhang ◽  
Gaodong Xu
Keyword(s):  
Energy Dissipation ◽  
Bearing Capacity ◽  
Failure Mode ◽  
Seismic Behavior ◽  
Load Transfer ◽  
Precast Concrete ◽  
Hysteretic Behavior ◽  
Experimental Investigations ◽  
Test Results ◽  
Energy Dissipation Capacity

In this study, two types of novel box connections were developed to connect precast concrete (PC) columns and to ensure load transfer integrity. Cyclic loading tests were conducted to investigate the seismic behavior of the PC columns with proposed connections as well as the feasibility and reliability of novel box connections. The failure mode, hysteretic behavior, bearing capacity, ductility, stiffness degradation and energy dissipation were obtained and discussed. The test results indicated that the all PC columns exhibited the ductile flexural failure mode and that the proposed connections could transfer the force effectively. The adoption of novel box connections could improve the deformation capacity and energy dissipation capacity of PC columns. A higher axial compression ratio could enhance the bearing capacity of PC column with proposed connection but would significantly deteriorate the ductility and energy dissipation capacity. Finite element models were developed and the feasibility of the models was verified by the comparison with the test results.

A New Method of Determining the Pile-Soil Parameters

2011 ◽  
Vol 368-373 ◽  
pp. 1566-1571
Author(s):  
Guang Qin Cui ◽  
Zeng Rong Liu ◽  
Chen Guang Ma
Keyword(s):  
Load Transfer ◽  
Load Test ◽  
Soil Parameters ◽  
Model Parameters ◽  
Static Load Test ◽  
Soil System ◽  
Soil Loading ◽  
S Curve ◽  
Transfer Method ◽  
Field Static

Basic transfer differential equation and transferring model of load transfer method were given at first, and the pile-soil loading state was divided into five stages according to the increasing pile-head loading process. Next, based on the overall equilibrium of pile and boundary conditions, analytical stiffness expressions of single pile relating to these transferring model parameters were derived in stages. And then, the field static load test result, Q-s curve, was also divided into five corresponding stages and subsection fitting was suggested to be made for each stage. Finally, each model parameter was determined one by one in stages according to the corresponding relations between the measured Q-s curve and the proposed analytical solutions. This pile-soil parameters determination method would enhance the application value of the measured Q-s curve in some extent, and it would provide a theoretical basis for further study on mechanical properties of pile-soil system.

scholarly journals Numerical Simulation Study Of Squeezed Branch Piles Based On Post-grouting Technology

2021 ◽  
Vol 292 ◽  
pp. 01038
Author(s):  
LiXing Ma ◽  
ZhuoPeng Shi ◽  
Kai Han ◽  
PengFei Chang ◽  
XiaoDong He
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
High Load ◽  
Single Pile ◽  
Horizontal Force ◽  
Load Bearing Capacity ◽  
Load Transfer Mechanism ◽  
Post Grouting ◽  
Vertical Bearing ◽  
Excellent Stability

The squeezed branch pile has strong resistance to pressure, pullout and horizontal force, and it also has excellent stability, which makes it widely used in the field of electrical engineering. Based on the ABAQUS, the paper simulates the vertical bearing situation of post-grouting squeezed branch piles, by setting up Set two comparisons of single pile and squeezed branch pile, the bearing capacity, load transfer mechanism and failure mode of post-grouting squeezed branch piles were comprehensively analyzed and compared. Studies have shown that the bearing capacity of the squeezed branch piles with post-grouting technology has increased by 68.1% compared with the traditional squeezed branch piles, and the bearing characteristics of the branches have changed greatly. In this process, the end-bearing function of the branch plate is fully exerted, and the high load-bearing capacity of the grouted strata soil is used to reduce the settlement.

scholarly journals Analysis of Vertical Load Transfer Mechanism of Assembled Lattice Diaphragm Wall in Collapsible Loess Area

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Mingtan Xia ◽  
Xudong Zhang ◽  
Gengshe Yang ◽  
Liu Hui ◽  
Wanjun Ye
Keyword(s):  
Failure Modes ◽  
Load Transfer ◽  
Diaphragm Wall ◽  
Vertical Load ◽  
Soil System ◽  
Loess Area ◽  
Collapsible Loess ◽  
Negative Friction ◽  
Vertical Bearing ◽  
Soil Interface

Based on analysis of the formation mechanism and characteristics of the negative friction in collapsible loess areas, this study investigates the load transfer law of a wall-soil system under a vertical load, establishes the vertical bearing model of a lattice diaphragm wall, and analyzes the vertical bearing capacity of an assembled latticed diaphragm wall (ALDW) in a loess area. The factors influencing the vertical bearing characteristics of the ALDW in a loess area are analyzed. The vertical bearing mechanism of the lattice diaphragm wall in the loess area is investigated. The failure modes of the ALDW in the loess area are mainly shear failure of the soil around the wall and failure of the wall-soil interface. In the generation and development of negative friction, there is always a point where the relative displacement of the wall-soil interface is zero at a certain depth below the ground; at this point, the wall and soil are relative to each other. The collapsibility of loess, settlement of the wall and surrounding soil, and rate and method of immersion are the factors affecting the lattice diaphragm wall. The conclusions of this study provide a reference for the design and construction of ALDWs in loess areas.

Experimental Study on Bearing Behavior of Large-Diameter Overlength Squeezed Branch Pile

2011 ◽  
Vol 243-249 ◽  
pp. 3244-3250
Author(s):  
Jin Lu Jia ◽  
Zhong Fu Wang ◽  
Jian Hua Zheng
Keyword(s):  
Bearing Capacity ◽  
Large Diameter ◽  
Load Ratio ◽  
The Body ◽  
Static Test ◽  
Force Transfer ◽  
Side Resistance ◽  
New Type ◽  
S Curve ◽  
Vertical Bearing

Squeezed branch pile is based on the traditional uniform pile in development of a new type of pile, with a high bearing capacity, settlement of small features widely used in the engineering. Based on the actual project site static test, analyzed the vertical bearing capacity characteristics of two adjacent squeezed branch piles; By means of testing of the pile stress gauge steel embedded in different parts of piles, the axial force transfer characteristics of the body, support plate side resistance drag and play characteristics of the squeezed branch pile were analyzed. The results showed that: the branch pile Q-S curve is slowly varying type, the three branch share of the load ratio increases with the pile top load increases and then decreases, load sharing ratio of 12% or so. The side resistance increased with the pile top displacement, the curve showed significant enhancement traits. Measured friction value of two test piles is too conservative under the existing norms, the actual measured value of 1.2～1.6 times of the standardized value.

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