scholarly journals Incorporating Setup Effects into the Reliability Analysis of Driven Piles

2021 ◽  
Vol 12 (1) ◽  
pp. 2
Author(s):  
Xiaoya Bian ◽  
Jiawei Chen ◽  
Xixuan Bai ◽  
Kunpeng Zheng
Keyword(s):  
Bearing Capacity ◽  
Reliability Analysis ◽  
Reliability Index ◽  
Engineering Application ◽  
Critical Parameters ◽  
Engineering Practice ◽  
Driven Piles ◽  
Pile Setup ◽  
Ultimate Resistance ◽  
Index Calculation

Driven-pile setup is referred to a phenomenon in which the bearing capacity of driven piles increases with time after the end of driving (EOD). The setup effect can significantly improve the bearing capacity (ultimate resistance) of driven piles after initial installation, especially the ultimate shaft resistance. Based on the reliability theory and considering the setup effects of driven piles, this article presents an increase factor (Msetup) for the ultimate resistance of driven piles to modify the reliability index calculation formula. At the same time, the correlation between R0 and Rsetup is comprehensively considered in the reliability index calculation. Next, the uncertainty analysis of load and resistance is conducted to determine the ranges of relevant parameters. Meanwhile, the influence of four critical parameters (factor of safety FOS, the ratio of dead load to live load ρ = QD/QL, Msetup, the correlation coefficient between R0 and Rsetup, and ρR0,Rsetup) on reliability index are analyzed. This parametric study indicates that ρ has a slight influence on the reliability index. However, the reliability index is significantly influenced by FOS, Msetup, and ρR0,Rsetup. Finally, by comparisons with the existing results, it is concluded that the formula proposed in this study is reasonable, and more uncertainties are considered to make the calculated reliability index closer to a practical engineering application. The presented formula clearly expresses the incorporation of the pile setup effect into reliability index calculation, and it is conducive to improving the prediction accuracy of the design capacity of driven piles. Therefore, the reliability analysis of driven piles considering setup effects will present a theoretical basis for the application of driven piles in engineering practice.

Reliability-Based Robust Design of Variable Cross-Section Wedge Beam

2012 ◽  
Vol 157-158 ◽  
pp. 74-77
Author(s):  
Tian Xiao Zhang ◽  
Xin Hui Liu ◽  
Qiao Ling Liu
Keyword(s):  
Normal Distribution ◽  
Reliability Analysis ◽  
Cross Section ◽  
Robust Design ◽  
Reliability Index ◽  
Variable Cross Section ◽  
Design Model ◽  
Engineering Practice ◽  
Variable Cross

Variable cross-section components are widely used in engineering practice. The paper discussed the reliability analysis, sensitivity numeration and robust design for variable cross-section components obeying normal distribution, built up the reliability-based robust design model, propose a method discussing reliability-based robust design of variable cross-section wedge beam. According to the numeration, obtain the graph of reliability index and reliability of variable cross-section components, obtain the method designing reliability-based robust of variable cross-section components with the certain reliability index.

Reliability Analysis of Subgrade Bearing Capacity of Gravity Foundation of Wind Turbine Based on JC Method

2011 ◽  
Vol 413 ◽  
pp. 314-319
Author(s):  
Zhong Qing Cheng ◽  
Ping Yang ◽  
Hai Bo Jiang
Keyword(s):  
Bearing Capacity ◽  
Wind Turbine ◽  
Reliability Analysis ◽  
Reliability Index ◽  
Maximum Pressure ◽  
Performance Function ◽  
Iterative Calculation ◽  
Reliability Method ◽  
Foundation Base ◽  
Index Effect

The design of foundation of wind turbine should meet the requirement of subgrade bearing capacity. In this paper, reliability method was used to analyze the bearing capacity of gravity foundation of wind turbine. The circular gravity foundation in coral sands is taken as research object. By deriving the expression of maximum pressure at the edge of foundation base under the action of overturning moment, the performance function of subgrade bearing capacity reliability analysis is established. JC method is used to calculate the subgrade bearing capacity reliability index. Effect of foundation size to reliability index is analyzed. Iterative calculation shows that the method proposed in this paper can calculate the reliability index of foundation quickly.

scholarly journals A Decoupling Strategy for Reliability Analysis of Multidisciplinary System with Aleatory and Epistemic Uncertainties

2021 ◽  
Vol 11 (15) ◽  
pp. 7008
Author(s):  
Chao Fu ◽  
Jihong Liu ◽  
Wenting Xu
Keyword(s):  
Reliability Analysis ◽  
Reliability Index ◽  
Uncertainty Propagation ◽  
Engineering Application ◽  
Performance Measure ◽  
Extreme Value Analysis ◽  
Convex Model ◽  
Value Analysis ◽  
Comprehensive Reliability ◽  
Multidisciplinary System

In reliability-based multidisciplinary design optimization, both aleatory and epistemic uncertainties may exist in multidisciplinary systems simultaneously. The uncertainty propagation through coupled subsystems makes multidisciplinary reliability analysis computationally expensive. In order to improve the efficiency of multidisciplinary reliability analysis under aleatory and epistemic uncertainties, a comprehensive reliability index that has clear geometric meaning under multisource uncertainties is proposed. Based on the comprehensive reliability index, a sequential multidisciplinary reliability analysis method is presented. The method provides a decoupling strategy based on performance measure approach (PMA), probability theory and convex model. In this strategy, the probabilistic analysis and convex analysis are decoupled from each other and performed sequentially. The probabilistic reliability analysis is implemented sequentially based on the concurrent subspace optimization (CSSO) and PMA, and the non-probabilistic reliability analysis is replaced by convex model extreme value analysis, which improves the efficiency of multidisciplinary reliability analysis with aleatory and epistemic uncertainties. A mathematical example and an engineering application are demonstrated to verify the effectiveness of the proposed method.

Reliability Method and its Standard of the Composite Foundation Bearing Capacity

2012 ◽  
Vol 170-173 ◽  
pp. 144-147
Author(s):  
Xiao Yun Peng ◽  
Peng Ju Cui
Keyword(s):  
Bearing Capacity ◽  
Reliability Analysis ◽  
Reliability Index ◽  
Limit State ◽  
State Equation ◽  
Composite Foundation ◽  
Analysis Method ◽  
Cement Injection ◽  
Reliability Method ◽  
General Reliability

The general reliability analysis method of composite foundation bearing capacity was established with the example of cement injection pile, its limit state equation and the optimize method was presented, and the standard of reliability index was also proposed according to the corresponding demand of architectural structure. It indicate that the method is reasonable, convenient to calculation and can be popularized in the whole geotechnical engineering.

scholarly journals A Vibration Reliability Analysis Method for the Uncertain Space Beam Structure

2016 ◽  
Vol 2016 ◽  
pp. 1-14
Author(s):  
Yanyu Mo ◽  
Shuxiang Guo ◽  
Cheng Tang
Keyword(s):  
Reliability Analysis ◽  
Frequency Analysis ◽  
System Reliability ◽  
Reliability Index ◽  
Engineering Practice ◽  
Analysis Method ◽  
Beam Structure ◽  
Reliability Method ◽  
Uncertain Structure ◽  
Vibration Reliability

Considering that uncertainty is inherent and unavoidable in engineering practice and the available information about the uncertain parameters is always not sufficient, the paper tries to carry out the nonprobabilistic vibration reliability analysis so as to avoid resonance on uncertain structure with bounded parameters. The input uncertain-but-bounded parameters are treated as interval variables, and an interval model is adopted to describe bounded uncertainties. Then a theory of nonprobabilistic reliability is introduced, in which the dimensionless nonprobabilistic reliability index and system reliability index are defined. In order to investigate the resonance failure with reliability method, the resonance failure domains are stated according to the relationships between the natural frequencies and the excitation frequencies. Then the uncertain structure is modeled as a series system and a system reliability index is proposed to evaluate the safety of the structure. The paper also takes a frequency analysis on the uncertain space beam structure to get the resonance failure modes. A frequency analysis method based on the monotonicity discriminant of the frequency sensitivity is presented. Then an optimization algorithm is introduced to verify the validity of the former frequency analysis method. Two examples are provided to illustrate the effectiveness and feasibility of the presented method.

The Research of Assessing and Strengthening One 40 Years Old Girder Arch Bridge

2014 ◽  
Vol 638-640 ◽  
pp. 1028-1031
Author(s):  
Jian Yu Yang ◽  
Peng Xiao Jiang
Keyword(s):  
Bearing Capacity ◽  
Reliability Analysis ◽  
Reliability Index ◽  
Safety Evaluation ◽  
Load Level ◽  
Arch Bridge ◽  
Dynamic Reliability ◽  
Vehicle Load ◽  
Capacity Change ◽  
Pavement Thickness

By investigating and examining one 40 years old girder arch bridge, this paper gets the current situation of the bridge. On account of these data, the reliability analysis and safety evaluation have been done, the reliability index was calculated, the dynamic reliability of the bridge was analyzed, and the disciplinarian of bearing capacity change with the deck pavement thickness and vehicle load level increasing was discuss. Moreover, the treatment project and strengthening measures was put forward.

Structural Analysis and Design of Slipway Floor with Anchor Jacked Piles

2014 ◽  
Vol 501-504 ◽  
pp. 185-192
Author(s):  
Can Mei ◽  
Xu Dong Fu ◽  
Ben Jiao Zhang
Keyword(s):  
Bearing Capacity ◽  
Moving Load ◽  
Engineering Application ◽  
Reference Value ◽  
Internal Force ◽  
Engineering Practice ◽  
Winkler Foundation ◽  
Shipbuilding Industry ◽  
Analysis And Design ◽  
Foundation Model

The rapid advance of shipbuilding industry generates greater demands on port and waterway engineering. The reconstruction and maintenance of infrastructure supporting shipbuilding industry also has aroused extensive attention. Since the tonnage of ship increases, the bearing capacity of slipway floors can’t meet the working requirement with the moving load of ships. As for the bearing capacity insufficiency, grouting, anchor jacked piles and bored piles are generally used. However, the anchor jacked pile has better practicality and applicability for easier to control construction quality and smaller damage to the original slipway floor. At present, methods based on Winkler foundation model have been more popular in the engineering practice. But Winkler foundation model can’t consider the interaction between pile and soil, the calculated structural internal force of slipway floor is far from the truth. In order to correct Winkler foundation model imperfections in this aspect, this paper provided the method of equivalent bedding value. In terms of area weighted means, the equivalent bedding value of pile and soil in the influence area would be got. Then this weighted area of pile and soil and other areas of soil could be equivalent to springs with different stiffness coefficients for calculating the structural internal force of slipway floor. To some degree, this method reduced the stress concentration on the top of piles and was closely to the reality, remedying some weaknesses of Winkler foundation model. This method may have definite reference value for foundation plate design in engineering application.

Reliability Analysis on the Foundation Bearing Capacity in Ningbo Rail Transit Engineering

2014 ◽  
Vol 580-583 ◽  
pp. 135-142
Author(s):  
Jian Feng Zhu ◽  
Gan Bin Liu ◽  
Jun Neng Ye
Keyword(s):  
Probability Distribution ◽  
Bearing Capacity ◽  
Normal Distribution ◽  
Reliability Analysis ◽  
Reliability Index ◽  
Soil Parameters ◽  
Rail Transit ◽  
Analysis Method ◽  
Safety Coefficient ◽  
Natural Density

According to the first-stage geologic investigation reports of the line 1 and line 2 in Ningbo rail transit, the natural density (ρ) and the vane strength (Cu) probability distribution of the typical layers in Ningbo area were studied in this paper. Besides, the reliabilities of the typical layers foundation bearing capacity in Ningbo area were evaluated by the checking point method. It is found that (1) the natural densities of the typical layers in Ningbo area show good normal distribution as their corresponding variation coefficients (δ) are small. Unfortunately, the vane strengths of the typical soils in Ningbo area show poor normal distribution as their corresponding variation coefficients (δ) are large. (2) The soil parameters variation has significant influence on the reliability index β. Moreover, β is more sensitive to the variation of ρ than to the variation of Cu. (3) As the safety coefficient methods can not consider the influence of the soil parameters variation on the foundation stability, it is suggested that the foundation stability in Ningbo area should be evaluated by the reliability analysis method.

Reliability Analysis of Concrete-Filled Tube Column

2012 ◽  
Vol 446-449 ◽  
pp. 667-671
Author(s):  
Lei Lei Liu
Keyword(s):  
Reliability Analysis ◽  
Carrying Capacity ◽  
Reliability Index ◽  
Slenderness Ratio ◽  
Engineering Application ◽  
Nonlinear Behavior ◽  
Steel Tube ◽  
Thickness Ratio ◽  
Analysis Model ◽  
Concrete Filled Tubes

To improve the accuracy of describing the nonlinear behavior of long concrete-filled tubes (CFT) and make the nonlinear reliability analysis method more valuable for engineering application, based on the response surface and nonlinear finite element method, the reliability analysis model for the nonlinear carrying capacity of concrete-filled steel tube structure is made, with the help of consistent mode imperfection method to consider the initial geometric defects of the structure. After a parametric analysis of the diameter-thickness ratio and the slenderness ratio, the application scope is examined. The numerical results show that as the slenderness ratio increases, the influence of the initial geometric defects on the reliability of carrying capacity increases gradually. It is suggested that when the slenderness ratio is bigger than 15, the effect of initial geometric defects on the reliability index should be included. Moreover, when the diameter-thickness ratio is smaller, influence of geometric nonlinearity on the reliability index of the carrying capacity is obvious.

Lamellar Tearing Observations Regarding the Application of European Standards in the Field of Welded Steel Constructions

2018 ◽  
Vol 69 (6) ◽  
pp. 1352-1354
Author(s):  
Anamaria Feier ◽  
Oana Roxana Chivu
Keyword(s):  
Bearing Capacity ◽  
Brittle Failure ◽  
Engineering Practice ◽  
Steel Bridge ◽  
Railway Bridge ◽  
Welded Steel ◽  
Direct Replacement ◽  
Lamellar Tearing ◽  
European Standards ◽  
Comprehensive Study

The problem of corrosion for old steel bridges in operation is often solved by direct replacement of elements or structure. Only a few studies have been done to determine the efforts influenced by corrosion in those elements. In general, it is considered that a corroded element has exceeded the bearing capacity and should be replaced, but if the corroded element is secondary it could be treated and kept. A factor in the rehabilitation of an old steel bridge in operation is the aspect of structure. If the structure is corroded, rehabilitation decision is taken is easier. Lamellar tearing describes the cracking that occurs beneath the weld and can be characterized as a brittle failure of steel, in the direction perpendicular to the plane of rolling. The paper presents a comprehensive study on lamellar tearing and summarizes some conclusions about the prevention of them. The conclusions will be exemplified in the case of a railway bridge, with a main truss girder. The paper presents also some observations regarding the stress analysis in fillet welds, resulting from the engineering practice.

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