Failure Probabilities of Reinforced Concrete Square Pile Caps

2007 ◽  
Vol 23 (2) ◽  
pp. 173-180
Author(s):  
W.-Y. Lu
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Design Method ◽  
Main Body ◽  
Concrete Pile ◽  
Diagonal Compression ◽  
Pile Cap ◽  
Pile Caps ◽  
Strut And Tie Model ◽  
Failure Probabilities

AbstractAn analytical model for determining the shear strength of concrete pile caps under the failure mode of diagonal-compression originally based on the softened strut-and-tie model is proposed. The failure probabilities of reinforced concrete pile caps are investigated by Monte Carlo method. The results indicate that the proposed model can accurately predict the shear strength of the pile caps. The distribution of the failure probabilities for pile caps designed to ACI 318-02 Appendix A and the proposed design method are more uniform than that designed to the ACI 318-99. The ACI 318-99 is very conservative and cannot provide a consistent safety for pile caps design. It is suggested that the procedures in the ACI 318-02 Appendix A should be moved to the main body of ACI 318-02 and the proposed design method should be incorporated into the current reinforced concrete pile cap design methods.

scholarly journals Analysis of nodal stress on reinforced concrete two-pile caps supported on steel piles

2020 ◽  
Vol 13 (6) ◽  
Author(s):  
Rodrigo Gustavo Delalibera ◽  
Marco Aurélio Tomaz ◽  
Vitor Freitas Gonçalves ◽  
José Samuel Giongo
Keyword(s):  
Reinforced Concrete ◽  
Structural Behavior ◽  
Concrete Piles ◽  
Strut And Tie ◽  
Concrete Pile ◽  
Steel Piles ◽  
Pile Cap ◽  
Pile Caps ◽  
Embedment Length ◽  
Strut And Tie Model

abstract: Reinforced concrete pile caps may be designed trough plastic models (strut and tie model) or models based on bending theory. The formulae available for verifying the stress is based on caps supported on concrete piles, with few studies about the stress distribution on caps supported on steel piles. To analyze the structural behavior of caps supported on steel piles, as well as the stress on the superior and inferior nodal zones, four two-pile caps supported on steel piles were tested. The variables were the embedment length and in one of the specimens a steel plate was welded on top of both piles. It was observed that the embedment length has substantial influence on pile cap structural behavior. It was concluded that, to verify the stress on inferior nodal zone of the cap, aside from pile area, an area of concrete confined between the flaps of the pile must be considered.

An evaluation of pile cap design methods in accordance with the Canadian design standard

2004 ◽  
Vol 31 (1) ◽  
pp. 109-119 ◽  
Author(s):  
William Cavers ◽  
Gordon A Fenton
Keyword(s):  
Reinforced Concrete ◽  
Structural Design ◽  
Design Methods ◽  
Building Codes ◽  
Design Models ◽  
Design Standard ◽  
Strut And Tie ◽  
Pile Cap ◽  
Pile Caps ◽  
Strut And Tie Model

There are a number of design methods that have been described for the design of pile caps, but there has been no consensus on which method provides the best approach for the working designer. This paper describes a study conducted to establish the performance of several pile cap design methods, particularly with respect to the Canadian standard, CSA A23.3-94. Previous research was examined to determine the basis of the design methods and the state of current research. The design methods identified were then applied to pile caps for which test data were available. The theoretical loads obtained using the various design methods were compared with the experimental loads. The results of this study indicate that two design models of the five examined are the most suitable. This study also indicates that the provisions of the Canadian design standard are adequate. A possible refinement of the strut-and-tie model incorporating a geometric limit is also outlined.Key words: building codes, footings, pile caps, reinforced concrete, structural design.

scholarly journals Enhanced strut-and-tie model for reinforced concrete pile caps

2017 ◽  
Author(s):  
Alexandre Mathern ◽  
Gautier Chantelot ◽  
Per-Ola Svahn ◽  
Per Kettil ◽  
Rasmus Rempling ◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Strut And Tie ◽  
Concrete Pile ◽  
Pile Caps ◽  
Strut And Tie Model

Strength predictions of pile caps by a strut-and-tie model approach

2008 ◽  
Vol 35 (12) ◽  
pp. 1399-1413 ◽  
Author(s):  
JungWoong Park ◽  
Daniel Kuchma ◽  
Rafael Souza
Keyword(s):  
Reinforced Concrete ◽  
American Concrete Institute ◽  
Valuable Insight ◽  
Strain Compatibility ◽  
Strut And Tie ◽  
Pile Cap ◽  
Pile Caps ◽  
Strut And Tie Model ◽  
And Behavior ◽  
Model Approach

In this paper, a strut-and-tie model approach is presented for calculating the strength of reinforced concrete pile caps. The proposed method employs constitutive laws for cracked reinforced concrete and considers strain compatibility. This method is used to calculate the load-carrying capacity of 116 pile caps that have been tested to failure in structural research laboratories. This method is illustrated to provide more accurate estimates of behavior and capacity than the special provisions for slabs and footings of the 1999 American Concrete Institute (ACI) code, the pile cap provisions in the 2002 CRSI design handbook, and the strut-and-tie model provisions in either the 2005 ACI code or the 2004 Canadian Standards Association (CSA) A23.3 standard. The comparison shows that the proposed method consistently well predicts the strengths of pile caps with shear span-to-depth ratios ranging from 0.49 to 1.8 and concrete strengths less than 41 MPa. The proposed approach provides valuable insight into the design and behavior of pile caps.

A Study on the Safety of the Shear Capacity Design of Reinforced Concrete Beam-Column Joints

2006 ◽  
Vol 22 (4) ◽  
pp. 311-320 ◽  
Author(s):  
W.-Y. Lu
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Beam ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Theoretical Shear Strength ◽  
Strut And Tie ◽  
Flexural Reinforcement ◽  
Strut And Tie Model ◽  
Failure Probabilities

AbstractThe shear failure probabilities of reinforced concrete beam-column joints have been investigated by Monte Carlo method. The theoretical shear strength of joints is based on the softened strut-and-tie model proposed by Hwang and Lee (2002). The random variables included in this study are the strengths of concrete, the ultimate compression strain of concrete, the strengths of reinforcement, the dimensions of cross-section, and the model error of theoretical shear strength of joints. The shear failure probabilities of joints with SD 280 flexural reinforcement in the beams designed using the ACI Code are all higher than 0.04. The joints designed according to the softened strut-and-tie model are safer than those designed according to the ACI Code. The shear failure probabilities of exterior joints are higher than those of interior joints. The shear failure probabilities of joints with SD 280 flexural reinforcement in the beams are higher than those of joints with SD 420 flexural reinforcement.

scholarly journals Analytical and Experimental Study of the Piles Cap Normal and Light Weight Aerated Concrete: Literature Review

2021 ◽  
Vol 27 (10) ◽  
pp. 86-105
Author(s):  
Noor Ali Hussien ◽  
Mohammed Mosleh Salman ◽  
Husain Khalaf Jarallah
Keyword(s):  
Reinforced Concrete ◽  
Shear Capacity ◽  
Shear Mode ◽  
Factors Affecting ◽  
Concrete Pile ◽  
Pile Cap ◽  
Pile Caps ◽  
Design Documents ◽  
The Many ◽  
And Behavior

The main objective of this study is to understand the work of the pile caps made of lightweight aerated foam concrete and study the many factors affecting the ability and the capacity of the shear. The study was done by analyzing previous practical and theoretical experiences on the reinforced concrete pile caps. The previous practical results indicated that all specimens failed by shear diagonal compression or tension modes except one specimen that failed flexural-shear mode. Based on test specimens' practical results and behavior, some theoretical methods for estimating the ultimate strength of reinforced concrete pile caps have been recommended, some of which evolved into the design documents available on the subject. A theoretical and practical study of compression concluded that the shear capacity is limited by the nodal zone bearing stresses. The flexural capacity can be described by the column load that would cause the yielding of the tie (i.e., steel reinforcement). Therefore, the design of pile caps should include a check on bearing strength to be added to the traditional section force approach for pile cap design.

Study on Mechanical Performance of Deep Pile Cap Failure

2015 ◽  
Vol 730 ◽  
pp. 39-42
Author(s):  
Hong Lei Guo
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Failure Mechanism ◽  
Mechanical Performance ◽  
Load Bearing Capacity ◽  
Truss Model ◽  
Concrete Pile ◽  
Pile Cap ◽  
Complete Procedure ◽  
Pile Caps

This paper presents the test of 3 reinforced concrete pile caps and the complete procedure of failure as well as the stressed mechanism, including the description of the occurrence of cracks. The influences of reinforcement types on load-bearing capacity are also probed. A spatial truss model is put forward and can explain satisfactorily some phenomena observed in the test and the failure mechanism is investigated.

scholarly journals Experimental study of reinforced concrete pile caps with external, embedded and partially embedded socket with smooth interface

2013 ◽  
Vol 6 (5) ◽  
pp. 737-750
Author(s):  
R. Barros ◽  
J.S. Giongo
Keyword(s):  
Experimental Study ◽  
Reinforced Concrete ◽  
Ultimate Load ◽  
Reference Model ◽  
Precast Concrete ◽  
Smooth Interface ◽  
Pile Cap ◽  
Pile Caps ◽  
Monolithic Connections ◽  
Scaled Models

On Precast concrete structures the column foundation connections can occur through the socket foundation, which can be embedded, partially embedded or external, with socket walls over the pile caps. This paper presents an experimental study about two pile caps reinforced concrete with external, partially embedded and embedded socket submitted to central load, using 1:2 scaled models. In the analyzed models, the smooth interface between the socket walls and column was considered. The results are compared to a reference model that presents monolithic connections between the column and pile cap. It is observed that the ultimate load of pile cap with external sockets has the same magnitude as the reference pile cap, but the ultimate load of models with partially embedded and embedded socket present less magnitude than the reference model.

Behaviour of precast reinforced concrete pile caps

2000 ◽  
Vol 14 (2) ◽  
pp. 73-78 ◽  
Author(s):  
Toong Khuan Chan ◽  
Chee Keong Poh
Keyword(s):  
Reinforced Concrete ◽  
Concrete Pile ◽  
Pile Caps
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