Review of Design Methods of the Ultimate Side Shear and Base Resistance for Rock-Socketed Pile

2013 ◽  
Vol 353-356 ◽  
pp. 60-67 ◽  
Author(s):  
Guo Liang Dai ◽  
Abdellatif Boucheloukh ◽  
Wei Ming Gong
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Ultimate Load ◽  
Load Capacity ◽  
Design Methods ◽  
Load Test ◽  
Rock Properties ◽  
Base Resistance ◽  
Ultimate Load Capacity ◽  
The Relationship

To determine the ultimate load capacity of drilled shaft socketed into rock under axial compression loading, it is necessary to predict both the ultimate side shear resistance and the base resistance based on field load test or/ and laboratory tests. In geotechnical engineering there are several methods proposed the relationship between rock properties (the unconfined compressive strength) and the ultimate side shears resistance and base resistance. This paper presents the review of design methods of ultimate side shear and base resistance for rock-socketed pile. These empirical functions depend on the socket type and the range of the unconfined compressive strength of rock.

Improvement of the Geotechnical Axial Design Methodology for Colorado's Drilled Shafts Socketed in Weak Rocks

2005 ◽  
Vol 1936 (1) ◽  
pp. 100-107 ◽  
Author(s):  
Naser M. Abu-Hejleh ◽  
Michael W. O'Neill ◽  
Dennis Hanneman ◽  
William J. Attwooll
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Design Methods ◽  
Drilled Shafts ◽  
Load Test ◽  
Empirical Methods ◽  
Weak Rocks ◽  
Rock Formations ◽  
Load Tests ◽  
Geotechnical Tests

Drilled shaft foundations embedded in weak rock formations support a large percentage of bridges in Colorado. Since the 1960s, empirical methods that entirely deviate from the AASHTO design methods have been used for the axial geotechnical design of these shafts. The margin of safety and expected shaft settlement are unknown in these empirical methods. Load tests on drilled shafts provide the most accurate design and research data for improvement of the design methods. Four Osterberg axial load tests were performed in Denver on drilled shafts embedded in soil-like claystone, very hard sandy claystone, and extremely hard clayey sandstone. An extensive program of simple geotechnical tests was performed at the load test sites, including standard penetration tests (SPT), unconfined compressive strength tests (UCT), and pressuremeter tests (PMT). Information on the construction and materials of the test shafts was documented, followed by thorough analysis of all test results. Conservative equations were suggested to predict the unconfined compressive strength and mass stiffness of weak rocks from SPT and PMT data. Colorado Department of Transportation (CDOT) and AASHTO–FHWA design methods for drilled shafts were thoroughly assessed. Design equations to predict the shaft ultimate unit base resistance ( qmax), side resistance ( fmax), and an approximate load–settlement curve as a function of the results of simple geotechnical tests were developed. The qualifications and limitations for using these design methods are presented (e.g., construction procedure, field conditions). Finally, a detailed strategic plan to identify the most appropriate design methods per LRFD for Colorado's drilled shafts was developed.

Ultimate Load Test and Analysis of a Retrofitted Model Steel Dome

1998 ◽  
Vol 13 (2) ◽  
pp. 53-63
Author(s):  
Hewen Li ◽  
Lewis C. Schmidt
Keyword(s):  
Finite Element ◽  
Ultimate Load ◽  
Load Capacity ◽  
Load Test ◽  
Finite Element Analyses ◽  
Loading Test ◽  
Ultimate Load Capacity ◽  
Geometrical Imperfections ◽  
Hexagonal Grids ◽  
Post Tensioned

This paper concerns the test and analysis of a retrofitted post-tensioned and shaped steel dome that failed in an original loading test. The post-tensioned and shaped steel dome was formed by a post-tensioning operation from a planar layout constituted of hexagonal grids. After its first loading to failure, the dome was retrofitted in situ. The retrofitting method and the results of a subsequent ultimate load test and nonlinear finite element analyses of the retrofitted dome are presented. It is found that the retrofitted dome has a much greater ultimate load capacity than the original dome. The results of finite element analyses show that the prestress member forces caused during shape formation can cause a reduction of ultimate load capacity, and that the post-tensioned and shaped steel dome investigated here is sensitive to geometrical imperfections. It is also noted that the retrofitting process can be used to erect a domic structure from a near flat layout. The proposed method of considering prestress forces can be useful in nonlinear analysis of structures involving prestress forces.

scholarly journals Theoretical Analysis of Factors Affecting Ultimate Nominal Load of Reinforced Concrete Axially Loaded Short Squire Columns (Pu) Comparing use Prokon Program

2021 ◽  
Vol 3 (2) ◽  
pp. 37-43
Author(s):  
Yasser I O Yahia ◽  
Manal O Suliman ◽  
Abdulrazzaq Jawish Alkherret ◽  
Shehdeh Ghannam
Keyword(s):  
Compressive Strength ◽  
Ultimate Load ◽  
Load Capacity ◽  
Ultimate Load Capacity ◽  
Factors Affecting ◽  
Load Carrying ◽  
Compressive Strength Of Concrete ◽  
Nominal Load ◽  
Axially Loaded ◽  
Loaded Column

One of this theoretical study, parameters that affecting the ultimate load capacity of the axially loaded column are studied. The parameters such as compressive strength of concrete and steel reinforcement ratio.  Throughout study a different value of each factor will be assumed. Then the nominal load-carrying capacity of axially loaded column was calculated for these different factors parameters according using the simplified methods provided in (ACI-318- 14) building code requirement for structural concrete and Prokon Program. It is observed that increasing the compressive strength of concrete result in improving the ultimate load capacity. Using compressive strength of concrete more than 40MPa which results in increasing of (Pu) from (2362kN) to(5918KN) . On other hand The total area of longitudinal reinforcement bars (AST), and the gross area of concrete section (Ag) have a significant effects also on increasing of (Pu) value but not as (Fcʹ).  

Discussion of “Ultimate Load Capacity of Arch Dams”

1967 ◽  
Vol 93 (3) ◽  
pp. 259-267
Author(s):  
Marek Janas ◽  
Lance A. Endersbee ◽  
M.L. Juncosa ◽  
K.V. Swaminathan ◽  
A. Rajaraman
Keyword(s):  
Ultimate Load ◽  
Load Capacity ◽  
Ultimate Load Capacity ◽  
Arch Dams

Performance of Reinforced Concrete Beams with Multiple Openings

2020 ◽  
Vol 857 ◽  
pp. 162-168
Author(s):  
Haidar Abdul Wahid Khalaf ◽  
Amer Farouk Izzet
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Concrete Beams ◽  
Load Capacity ◽  
Reinforced Concrete Beams ◽  
Design Parameters ◽  
Ultimate Load Capacity ◽  
Concentrated Load ◽  
Simply Supported ◽  
Group I

The present investigation focuses on the response of simply supported reinforced concrete rectangular-section beams with multiple openings of different sizes, numbers, and geometrical configurations. The advantages of the reinforcement concrete beams with multiple opening are mainly, practical benefit including decreasing the floor heights due to passage of the utilities through the beam rather than the passage beneath it, and constructional benefit that includes the reduction of the self-weight of structure resulting due to the reduction of the dead load that achieves economic design. To optimize beam self-weight with its ultimate resistance capacity, ten reinforced concrete beams having a length, width, and depth of 2700, 100, and 400 mm, respectively were fabricated and tested as simply supported beams under one incremental concentrated load at mid-span until failure. The design parameters were the configuration and size of openings. Three main groups categorized experimental beams comprise the same area of openings and steel reinforcement details but differ in configurations. Three different shapes of openings were considered, mainly, rectangular, parallelogram, and circular. The experimental results indicate that, the beams with circular openings more efficient than the other configurations in ultimate load capacity and beams stiffness whereas, the beams with parallelogram openings were better than the beams with rectangular openings. Commonly, it was observed that the reduction in ultimate load capacity, for beams of group I, II, and III compared to the reference solid beam ranged between (75 to 93%), (65 to 93%), and (70 to 79%) respectively.

scholarly journals Experimental Study on the Effect of Heel Plate Length on the Structural Integrity of Cold-formed Steel Roof Trusses

2018 ◽  
Vol 65 ◽  
pp. 08010
Author(s):  
Je Chenn Gan ◽  
Jee Hock Lim ◽  
Siong Kang Lim ◽  
Horng Sheng Lin
Keyword(s):  
Ultimate Load ◽  
Structural Integrity ◽  
Load Capacity ◽  
Local Buckling ◽  
Ultimate Capacity ◽  
Ultimate Load Capacity ◽  
Plate Length ◽  
Roof Truss ◽  
Cold Formed Steel ◽  
Structural Failures

Applications of Cold-Formed Steel (CFS) are widely used in buildings, machinery and etc. Many researchers began the research of CFS as a roof truss system. It is required to increase the knowledge of the configurations of CFS roof trusses due to the uncertainty of the structural failures regarding the materials and rigidity of joints. The objective of this research is to investigate the effect of heel plate length to the ultimate load capacity of CFS roof truss system. Three different lengths of heel plate specimens were fabricated and subjected to concentrated loads until failure. The highest ultimate capacity for the experiment was 30 kN. The results showed that the increment of the length of the heel plate had slightly increased the ultimate capacity and strain. The increment of the length of the heel plate had increased the deflection of the bottom chords but decreased the deflection of the top chords. Local buckling of top chords adjacent to the heel plate was the primary failure mode for all the heel plate specimens.

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