scholarly journals Calibration of Load and Resistance Factors for Breakwater Foundation Design. Application on Different Types of Superstructures

2021 ◽  
Vol 33 (6) ◽  
pp. 287-292
Author(s):  
Jungwon Huh ◽  
Nhu Son Doan ◽  
Van Ha Mac ◽  
Van Phu Dang ◽  
Dong Hyawn Kim
Keyword(s):  
Wave Loading ◽  
Efficient Design ◽  
Foundation Design ◽  
Resistance Factors ◽  
Different Types ◽  
Load And Resistance Factors ◽  
Factor Design ◽  
Load And Resistance Factor ◽  
Perforated Caisson ◽  
Rubble Mound Breakwaters

Load and resistance factor design is an efficient design approach that provides a system of consistent design solutions. This study aims to determine the load and resistance factors needed for the design of breakwater foundations within a probabilistic framework. In the study, four typical types of Korean breakwaters, namely, rubble mound breakwaters, vertical composite caisson breakwaters, perforated caisson breakwaters, and horizontal composite breakwaters, are investigated. The bearing capacity of breakwater foundations under wave loading conditions is thoroughly examined. Two levels of the target reliability index (RI) of 2.5 and 3.0 are selected to implement the load and resistance factors calibration using Monte Carlo simulations with 100,000 cycles. The normalized resistance factors are found to be lower for the higher target RI as expected. Their ranges are from 0.668 to 0.687 for the target RI of 2.5 and from 0.576 to 0.634 for the target RI of 3.0.

scholarly journals Improved Calculation of Load and Resistance Factors Based on Third-Moment Method

2021 ◽  
Vol 11 (19) ◽  
pp. 9107
Author(s):  
Jiao Wang ◽  
Xinying Ye ◽  
Weiji Zheng ◽  
Peng Liu
Keyword(s):  
Moment Method ◽  
Random Variables ◽  
Reliability Design ◽  
Resistance Factors ◽  
Iterative Computation ◽  
Load And Resistance Factors ◽  
Applicable Range ◽  
Factor Design ◽  
Load And Resistance Factor ◽  
Third Moment

Load and resistance factor design (LRFD) is widely used in building codes for reliability design. In the calculation of load and resistance factors, the third-moment method (3M) has been proposed to overcome the shortcomings (e.g., inevitable iterative computation, requirement of probability density functions (PDFs) of random variables) of other methods. With the existing 3M method, the iterative is simplified to one computation, and the PDFs of random variables are not required. In this paper, the computation of load and resistance factors is further simplified to no iterations. Furthermore, the accuracy of the proposed method is proved to be higher than the existing 3M methods. Additionally, with the proposed method, the limitations regarding applicable range in the existing 3M methods are avoided. With several examples, the comparison of the existing 3M method, the ASCE method, the Mori method, and the proposed method is given. The results show that the proposed method is accurate, simple, safe, and saves material.

Calibration concepts for load and resistance factor design (LRFD) of reinforced soil walls

2008 ◽  
Vol 45 (10) ◽  
pp. 1377-1392 ◽  
Author(s):  
Richard J. Bathurst ◽  
Tony M. Allen ◽  
Andrzej S. Nowak
Keyword(s):  
Limit State ◽  
Reinforced Soil ◽  
Resistance Factor ◽  
Resistance Factors ◽  
Soil Walls ◽  
Calibration Methods ◽  
Load And Resistance Factors ◽  
Factor Design ◽  
Load And Resistance Factor ◽  
Reinforced Soil Walls

Reliability-based design concepts and their application to load and resistance factor design (LRFD or limit states design (LSD) in Canada) are well known, and their adoption in geotechnical engineering design is now recommended for many soil–structure interaction problems. Two important challenges for acceptance of LRFD for the design of reinforced soil walls are (i) a proper understanding of the calibration methods used to arrive at load and resistance factors, and (ii) the proper interpretation of the data required to carry out this process. This paper presents LRFD calibration principles and traces the steps required to arrive at load and resistance factors using closed-form solutions for one typical limit state, namely pullout of steel reinforcement elements in the anchorage zone of a reinforced soil wall. A unique feature of this paper is that measured load and resistance values from a database of case histories are used to develop the statistical parameters in the examples. The paper also addresses issues related to the influence of outliers in the datasets and possible dependencies between variables that can have an important influence on the results of calibration.

The basis for load and resistance factor design criteria of steel building structures

1977 ◽  
Vol 4 (2) ◽  
pp. 178-189 ◽  
Author(s):  
T. V. Galambos ◽  
M. K. Ravindra
Keyword(s):  
Research Work ◽  
Resistance Factor ◽  
Building Structures ◽  
Resistance Factors ◽  
First Order ◽  
Steel Building ◽  
Load And Resistance Factors ◽  
Factor Design ◽  
Load And Resistance Factor ◽  
Work Done

This paper will detail the assumptions, the first-order probabilistic basis, the calibration, and the proposed format of load and resistance factor design (LFRD) criteria for steel building structures. Specifically, the paper will concern itself with the background and the choice of the particular first-order model, with the data bases used in evaluating the loading and the resistance functions, with the calibration procedures, and with the final selection of the load and resistance factors. The method will be illustrated by the examples of beams and columns under dead and live loading. The paper will conclude with a brief review of the research work done in connection with the development of LRFD criteria for steel building structures.

Consequence factors in the ultimate limit state design of shallow foundations

2011 ◽  
Vol 48 (2) ◽  
pp. 265-279 ◽  
Author(s):  
Gordon A. Fenton ◽  
D. V. Griffiths ◽  
Olaide O. Ojomo
Keyword(s):  
Limit State ◽  
Shallow Foundations ◽  
Resistance Factor ◽  
Shallow Foundation ◽  
Ultimate Limit State ◽  
Resistance Factors ◽  
Limit State Design ◽  
Reliability Based Design ◽  
Load And Resistance Factors ◽  
Load And Resistance Factor

The reliability-based design of shallow foundations is generally implemented via a load and resistance factor design methodology embedded in a limit state design framework. For any particular limit state, the design proceeds by ensuring that the factored resistance equals or exceeds the factored load effects. Load and resistance factors are determined to ensure that the resulting design is sufficiently safe. Load factors are typically prescribed in structural codes and take into account load uncertainty. Factors applied to resistance depend on both uncertainty in the resistance (accounted for by a resistance factor) and desired target reliability (accounted for by a newly introduced consequence factor). This paper concentrates on how the consequence factor can be defined and specified to adjust the target reliability of a shallow foundation designed to resist bearing capacity failure.

Resistance Factors for Drilled Shafts in Weak Rock Based on O-Cell Test Data

2008 ◽  
Vol 2045 (1) ◽  
pp. 62-67 ◽  
Author(s):  
Xiaoming Yang ◽  
Jie Han ◽  
Robert L. Parsons ◽  
Robert W. Henthorne
Keyword(s):  
Test Data ◽  
Drilled Shafts ◽  
Rock Properties ◽  
Weak Rock ◽  
Foundation Design ◽  
Resistance Factors ◽  
Side Resistance ◽  
Measured Resistance ◽  
Log Normal ◽  
Load And Resistance Factor

Load and resistance factor design (LRFD) has been mandatory for all FHWA-funded bridges since October 2007. The resistance factors included in the current AASHTO specifications for foundation design are not all calibrated by using field data. A calibration of resistance factors for side resistance of drilled shafts in weak rock is based on the statistical data collected from 19 O-cell tests in the midwestern United States. The field test data were used to determine the measured resistance, and the in situ rock properties and the dimensions of drilled shafts were used to calculate the predicted resistance by using the FHWA method. The Monte Carlo method was selected to perform the calibration. On the basis of the normally distributed loads and log normal distributed resistance from the test data, side resistance factors were determined at a target reliability index of 3.0. The calibrated resistance factors were compared with those in the current AASHTO LRFD Bridge Design Specifications.

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