scholarly journals Comparison and analysis of conversion methods for self-balancing test of pile bearing capacity

2021 ◽  
Vol 293 ◽  
pp. 02041
Author(s):  
Yonggang Qiu ◽  
Chuansheng Huang ◽  
Renhao Hong ◽  
Chunhan Chen ◽  
Jinxiang Yi ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Reference Value ◽  
Load Test ◽  
The Self ◽  
Equivalent Transformation ◽  
Displacement Curve ◽  
Static Load Test ◽  
Advantages And Disadvantages ◽  
Load Displacement ◽  
S Curve

The principle and method of self-balancing test are introduced briefly. In this article, through comparison of common Q-S curve of equivalent transformation to transform from the balance of the measured load-displacement curve for the traditional method of load - displacement curve, puts forward the advantages and disadvantages of each, through the three bored piles in static load test of pile reaction from balance to detect vertical compressive ultimate bearing capacity of single pile is in line with the requirements and compare the load-displacement curve after conversion. Some problems of the self-balancing method in engineering are pointed out, which is of certain reference value to the popularization and application of the self-balancing test of pile bearing capacity.

Numerical Analysis and Experimental Study of Carbon Fiber Reinforced Composite Joints under Bending Load

2021 ◽  
Vol 1163 ◽  
pp. 40-47
Author(s):  
Xi Lin Luo ◽  
Jian Hui Wei ◽  
Xue Kang Zhu ◽  
Hong Yin
Keyword(s):  
Failure Mode ◽  
Progressive Failure ◽  
Three Dimensional ◽  
Load Test ◽  
Bending Test ◽  
Displacement Curve ◽  
Composite Joints ◽  
Static Load Test ◽  
Bending Load ◽  
Load Displacement

Three dimensional finite element models of composite joints were established to investigate the load-displacement behavior, failure mode of multi-axial tubular joints under bending load, and stress-strain relationship in some key positions. The joints were prepared by plain weave fabric. The effective elastic constants of fabric composite were calculated using meso-mechanics theory. A progressive failure analysis was performed using ABAQUS software to obtain the ultimate strength and failure mode of the sample. In addition, the damage process, failure mode and damage position was further studied. The bending properties of the joints were also presented by quasi-static load test using a three-point bending test device. Results of the ultimate load and damage analyses are compared to experimental data. The accuracy of the method was proved by the consistency of the relation between the load displacement curve trend and the correlation of the damage position and failure pattern.

Prediction of Vertical Ultimate Bearing Capacity in Piles Based on the Improved Hyperbolic Model

2011 ◽  
Vol 250-253 ◽  
pp. 2271-2275
Author(s):  
Cheng Wang ◽  
Qi Zhang
Keyword(s):  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Load Test ◽  
Hyperbolic Model ◽  
Maximum Point ◽  
Static Load Test ◽  
Hyperbolic Curve ◽  
The Mathematical Model ◽  
Test Pile

Vertical static load test is widely used in the determination of pile bearing capacity, the mathematical model used to fit test pile data in determining the bearing capacity is essential. From the perspective of analytic geometry, the paper analyzes the traditional method of hyperbola, of which the asymptotic line of equilateral hyperbola was used to determine the ultimate bearing capacity. By extending the equal-axed conditions, a more general form of hyperbolic equation is derived and feasibility of such method is also analyzed, which indicates that the maximum point of curvature in such hyperbolic curve can determine the ultimate bearing capacity and such method is proved to be reasonable in practical projects.

Study on the Stability and Structural Optimization of Self-Elevating Platform Pile Foundation

2012 ◽  
Vol 203 ◽  
pp. 325-328
Author(s):  
Xin Jie Chu
Keyword(s):  
Stress Concentration ◽  
Structural Optimization ◽  
Bearing Capacity ◽  
Pile Foundation ◽  
Reference Value ◽  
The Self ◽  
Foundation Design ◽  
Operation Stability ◽  
Soil Foundation ◽  
The Stability

This paper analyzes the stability and structural optimization of self-elevating platform pile foundation, preliminarily discusses the method of analyzing the bearing capacity of the layer soil foundation, and establishes the numerical computation models for the whole platform, pile, pile shoe, etc. Besides, through these analyses, the pile structure is optimized, and the stress concentration in the joint between pile and pile shoe is reduced. Also, this study is of reference value for the analysis on the self-elevating platform pile foundation design and the platform operation stability.

Numerical Analysis on the Bearing Capacity of Single Pile in Deep Excavation Area

2013 ◽  
Vol 671-674 ◽  
pp. 226-229
Author(s):  
Jun Jie Wu ◽  
Jin Jian Chen ◽  
Shuai Jun Liu ◽  
Jian Hua Wang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Numerical Study ◽  
Back Analysis ◽  
Load Test ◽  
Deep Excavation ◽  
Static Load Test ◽  
Fem Modeling ◽  
Vertical Bearing ◽  
Element Technique

Large-scale deep excavation may affect the bearing capacity of piles inside the excavation zone. It does not only cause the loss of friction, but also change the stress state of the subsoil. In this paper, nonlinear finite element technique is employed to investigate the bearing capacity of piles influenced by the deep excavation. Parameters of soil are obtained by back analysis on the pile static load test results. The bearing capacity of the piles during excavation is analyzed by performing FEM modeling under three conditions using the calibrated parameters. The numerical study shows that the loss ratio of vertical bearing capacity of pile foundation caused by excavation unloading is 34%.

FULL SCALE STATIC LOAD TEST ON THE SPIDER NET SYSTEM

2015 ◽  
Vol 77 (11) ◽  
Author(s):  
Helmy Darjanto ◽  
Masyhur Irsyam ◽  
Sri Prabandiyani Retno
Keyword(s):  
Bearing Capacity ◽  
Load Transfer ◽  
Static Load ◽  
Full Scale ◽  
Load Test ◽  
Static Load Test ◽  
Specific Element ◽  
Soil Stratum ◽  
Applied Loading ◽  
Shallow Footing

The Spider Net System Footing (SNSF) is a raft foundation system that commonly used in Indonesia. It contains a plate, downward ribs system for reinforcement, and the compacted filled soil. The ribs are in longitudinal and transversal, called as settlement rib and in diagonal direction, named as construction rib. This paper explores the load transfer mechanism along the plate, the ribs, filled soil and the base soil under the footing system. The mechanism is investigated by conducting full scale static load test on SNSF. Strain gauges were installed to monitor the strain increment of each footing elements during loading. 3D numerical analysis was also conducted to verify the experimental results. To analyze the results, Load-Ultimate Ratio Factor (L-URF) was proposed. L-URF was a ratio between ultimate soil bearing capacity of the SNSF and the applied loading at specific element. Higher the L-URF value means higher loading applied at its associate element. Both experimental and numerical results show that at the first stage the loading was fully carried out by the tip of the ribs and transferred to the soil stratum under the footing system. Increasing the loading, the ribs, plate, and filled soil altogether sustain the loading and then transferred to the soil stratum below the footing system. The results also affirm that SNSF generate higher bearing capacity compare with simple shallow footing.  

scholarly journals Influence of Existing Defects on Mechanical Properties of NC Lining

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Sen Zhang ◽  
Zhihua Ren ◽  
Zude Ding ◽  
Jincheng Wen ◽  
Zhixin Yan
Keyword(s):  
Mechanical Properties ◽  
Mechanical Behavior ◽  
Bearing Capacity ◽  
Safety Evaluation ◽  
Scale Model ◽  
Concrete Lining ◽  
Displacement Curve ◽  
Deformation Properties ◽  
S Curve ◽  
Combined Defects

The mechanical properties of the lining are directly affected by defects such as voids behind the lining and insufficient thickness of the lining. In order to quantitatively evaluate this effect, the mechanical behavior of the lining under the influence of the void behind the lining, the insufficient thickness of the lining, and the combination of the two kinds of defects are adopted by the 1/5 scale model test. Based on the experimental research, numerical calculation models based on the CDP model for defect lining are established, with the effects of load direction, stratum stiffness, defect location, defect type, and degree on the mechanical behavior of the lining analyzed by the numerical simulation. The experimental and numerical results show that the void weakens the stiffness of the lining. As the void range increases, the lining becomes more deformable and its bearing capacity decreases with the “S” curve. Thinning significantly reduces the deformation properties of the lining and the bearing capacity and stiffness of the thinned section. The lining bearing capacity decreases linearly with the increase of the thinning ratio, when the load is applied at the thinning. With the influence of combined defects on the load-displacement curve of the lining fluctuating drastically, the mechanical properties of the lining are significantly reduced. The bearing capacity of lining decreases with the increase of composite defects in a “S” shape. The effect of void and lining thinning on the lining bearing capacity increases with the increase of the stiffness of the formation. The loss rate equation of the concrete lining bearing capacity under the influence of existing defects is established by using the L-M nonlinear regression analysis, a provision of scientific guidance for the safety evaluation of the defect lining.

Experimental Study on Flexural Performance of Prefabricated RC Slabs with Different Rebar Forms at Seam

2014 ◽  
Vol 1065-1069 ◽  
pp. 1187-1190
Author(s):  
Hong Yu Zheng ◽  
Huai Yan Jiang ◽  
Yan Qing Wu ◽  
Zhi Qiang Zhao ◽  
Yong Chun Zeng ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Load Test ◽  
Thin Wall ◽  
Static Load Test ◽  
Flexural Performance ◽  
Reinforced Concrete Slabs ◽  
Rc Structure ◽  
Rc Slab ◽  
Flexural Bearing Capacity ◽  
Rc Slabs

Four pairs of prefabricated reinforced concrete slabs were designed, cast, cured, assembled and test to investigate the flexural performance of prefabricated underground thin-wall box RC structure. One traditional integrated slab specimen with same size, material and reinforcement was also cast and test for comparison purpose. Four rebar constructional forms were conceived to compare the ability of transferring tension force between two slabs. Symmetric two-points monotonic static load test were performed to attain their flexural performance. The test results indicates: the prefabricated RC slab can provide better deformability and ductility, but the flexural bearing capacity is lower, comparing with cast-in-situ integrated RC slab; steel rebar form at seam have some effect on the flexural bearing capacity of prefabricated RC slab.

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.

Experiment Research on Bored Pile with Post-Grouting Technology

2013 ◽  
Vol 838-841 ◽  
pp. 854-857
Author(s):  
Rui Chao Cheng ◽  
Xin Yu
Keyword(s):  
Bearing Capacity ◽  
Static Load ◽  
Load Test ◽  
Static Load Test ◽  
Pile Head ◽  
Experiment Research ◽  
Friction Resistance ◽  
Bored Pile ◽  
Post Grouting ◽  
Side Friction

The bearing capacity characteristics and side friction characters of post-grouting pile were studied in the static load test which included two piles with post-grouting or not. When the pile head settlements were same, the loads applied on the pile top were used to analyze the bearing properties of post-grouting pile. We got the ultimate side friction of post-grouting pile after fitting test curves of relations between friction resistance and displacement. The tests indicate that both the bearing capacity characteristics and side friction of post-grouting pile are increased in various degrees.

scholarly journals Static Load Tests, Short Series Interpretation

2015 ◽  
Vol 36 (2) ◽  
pp. 45-49 ◽  
Author(s):  
Zygmunt Meyer
Keyword(s):  
Critical Load ◽  
Bearing Capacity ◽  
Static Load ◽  
Critical Value ◽  
Load Test ◽  
Practical Calculation ◽  
Short Series ◽  
Load Tests ◽  
S Curve

Abstract Statistic load test is the most commonly used method for estimation of the bearing capacity of piles. From the test we obtain the series a values: load-settlement, Q–s curve. In practice, it is extremely difficult to reach the critical load of the pile when the settlement turns out of control. The existing methods that allow bearing capacity to be calculated give the value which is very often 1/10 of the critical load. The question arises if it is possible based upon short series of load, i.e., 0–0.4 critical load, to predict the critical value of the load, with accuracy which is sufficient for practical calculation. The paper presents a method how to calculate the critical load based upon short series of load in the static load tests.

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