Reliability analysis of rigid pile caps using an iterative strut-and-tie model

• Autorzy: Araújo J. M.
• Języki publikacji: EN

Abstrakty

EN

The aim of this work is to present a new strut-and-tie model for design of rigid pile caps based on the concept of magnified area under the column. In this magnified area, compressive stresses have been reduced enough not to cause crushing of the struts. An iterative algorithm is used to determine the required depth of the magnified area. The model considers both failure by crushing of the compressed struts and by yielding of the tie reinforcement. A large number of experimental results available in the literature is used to test the model. The partial safety factors method is employed for pile caps design and structural safety is evaluated by means of the reliability index. The small failure probability, estimated through the reliability index, demonstrates the safety of the proposed method. A numerical example of practical use of the model is also presented.

PL

Celem pracy było przedstawienie nowego modelu S-T do projektowania sztywnych oczepów fundamentów palowych opartego na koncepcji zwiększonego pola u podstawy słupa. W obrębie tak powiększonego pola powierzchni naprężenia ściskające zostały zredukowane na tyle, aby nie doprowadzić do zmiażdżenia krzyżulców ściskanych. Algorytm iteracyjny został wykorzystany do określenia wymaganej głębokości odpowiadającej powiększonemu polu przekroju naprężeń. W modelu wzięto pod uwagę zarówno zniszczenie przez zmiażdżenie krzyżulców ściskanych, jak i w wyniku uplastycznienia prętów rozciąganych. W celu weryfikacji modelu wykorzystano dużą liczbę wyników badań literaturowych. Przy projektowaniu oczepów fundamentów palowych przyjęto częściowe współczynniki bezpieczeństwa, a bezpieczeństwo konstrukcji zostało określone przy przyjęciu wskaźnika niezawodności. Niskie prawdopodobieństwo zniszczenia, określone z wykorzystaniem wskaźnika niezawodności, pokazuje wysoki poziom bezpieczeństwa dla przedstawionej metody. Dodatkowo przedstawiono praktyczne zastosowanie modelu na przykładzie numerycznym.

Słowa kluczowe

EN

strut-and-tie; pile caps; reinforced concrete; structural design; structural safety

PL

strut-and-tie; oczepy fundamentów palowych; beton zbrojony; projektowanie konstrukcji; bezpieczeństwo konstrukcji

• Wydawca: Silesian University of Technology
• Czasopismo: Architecture Civil Engineering Environment
• Rocznik: 2017
• Tom: Vol. 10, no. 2
• Strony: 65--75
• Opis fizyczny: Bibliogr. 31 poz.

Twórcy

autor

Araújo J. M.

• Engineering School, Federal University of Rio Grande, Av. Itália, km 8, Rio Grande, RS, 96203-900 – Brazil

Bibliografia

• [1] Schlaich J., Schäfer K., Jennewein M. (1987). Toward a consistent design of structural concrete. PCI Journal 32(3), 74–150.
• [2] ACI; (2014). Building Code Requirements for Structural Concrete (ACI 318-14) and Commentary (ACI 318R-14). American Concrete Institute, Farmington Hills, MI, USA.
• [3] JSCE; (2010). Standard Specifications for Concrete Structures – 2007, Design. JSCE Guidelines for Concrete No.15, Japan Society of Civil Engineers. Tokyo, Japan.
• [4] EHE; (2011). Instruction for Structural Concrete. EHE-08, Comisión Permanente Del Hormigón, Madrid, Spain (in Spanish).
• [5] EN 1992-1-1; (2014). Eurocode 2: Design of Concrete Structures – Part 1-1: General Rules and Rules for Buildings. EN 1992-1-1:2004+A1:2014, European Committee For Standardization, Brussels, Belgium.
• [6] FIB; fib Model Code 2010. International Federation For Structural Concrete, Lausanne, Switzerland.
• [7] Adebar P., Zhou Z. (1996). Design of deep pile caps by strut-and-tie models. ACI Structural Journal, 93(4), 1–12.
• [8] Brown M.D., Sankovich C.L., Bayrak O., Jirsa J.O., Breen J.E., Wood S.L. (2006). Design for Shear in Reinforced Concrete Using Strut-and-Tie Models. Report No. FHWA/TX-06/0-4371-2. Center for Transportation Research, The University of Texas at Austin, USA.
• [9] Chantelot G.,Mathern, A. (2010). Strut-and-tie modelling of reinforced concrete pile caps. Master of Science Thesis, Chalmers University of Technology, Sweden.
• [10] ACI. (2010). Further Examples for the Design of Structural Concrete with Strut-and-Tie Models. ACI SP-273, American Concrete Institute, Farmington Hills, MI, USA.
• [11] Araújo J.M. (2016). Design of rigid pile caps through an iterative strut-and-tie model. Journal of Advanced Concrete Technology 14(8), 397–407.
• [12] CSA. (2014). A23.3-14: Design of Concrete Structures. Canadian Standards Association, Mississauga, Ontario, Canada.
• [13] CEB-FIP. (1993). CEB-FIP Model Code 1990. Comité Euro-International Du Béton, edited by Thomas Telford, London, UK.
• [14] Fusco P.B. (1995). Technique of Arming Concrete Structures. Pini, São Paulo, Brazil (in Portuguese).
• [15] Jimenez Montoya P., Garcia Mesegner A., Moran Cabre F. (2000). Reinforced Concrete. 14nd ed. Gustavo Gili , Barcelona (in Spanish).
• [16] Calavera J. (2000). Calculation of Foundation Structures. 4nd ed. INTEMAC, Madrid (in Spanish).
• [17] Adebar P., Kuchma D., Collins M. P. (1990). Strutand- tie models for the design of pile caps: an experimental sudy. ACI Structural Journal. 87(1), 81–92.
• [18] Araújo J.M. (2001). Probabilistic analysis of reinforced concrete columns. Advances in Engineering Software 32(12), 871–879.
• [19] Ang A.H.S., Tang W.H. (1984). Probability Concepts in Engineering Planning and Design – Vol. II: Decision, Risk and Reliability. John Wiley & Sons, New York, NY, USA.
• [20] Munhoz F.S. (2014). Experimental and numerical analysis of rigid two-pile caps with columns of square and rectangular sections and different reinforcement rates. Doctoral thesis, Escola de Engenharia de São Carlos, USP, São Carlos, Brazil (in Portuguese).
• [21] Mautoni M. (1972). Pile Caps on Two Supports. Grêmio Politécnico, São Paulo, SP, Brazil, (in Portuguese).
• [22] Blévot J., Frémy R. (1967). Semelles sur pieux, (The pile caps). Institut Technique du Batiment et des Travaux Publics 20(230), 223–295.
• [23] Miguel M.G. (2000). Experimental and numerical analysis of three-pile caps. Doctoral thesis, Escola de Engenharia de São Carlos, USP, São Carlos, Brazil. (in Portuguese).
• [24] Clarke J.L. (1973). Behavior and Design of Pile Caps with Four Piles, Technical Report No. 42.489, Cement and Concrete Association, London, UK.
• [25] Suzuki K., Otsuki K., Tsubata T. (1998). Influence of bar arrangement on ultimate strength of four-pile caps. Transactions of the Japan Concrete Institute, 20, Tokyo, Japan.
• [26] Suzuki K., Otsuki K., Tsubata T. (1999). Experimental study on four-pile caps with taper. Transactions of the Japan Concrete Institute (21), Tokyo, Japan.
• [27] Suzuki K., Otsuki K., Tsuhiya T. (2000). Influence of edge distance on failure mechanism of pile caps. Transactions of the Japan Concrete Institute, 22, Tokyo, Japan.
• [28] Suzuki K,, Otsuki K. (2002). Experimental study on corner shear failure of pile caps. Transactions of the Japan Concrete Institute (23), Tokyo, Japan.
• [29] Souza R., Kuchma D., Park J., Bittencourt T. (2009). Adaptable strut-and-tie model for design and verification of four-pile caps. ACI Structural Journal, 106(2), 142–150.
• [30] EN 1990; (2009). Eurocode – Basis of Structural Design. European Committee For Standardization, Brussels, Belgium.
• [31] Haldar A., Mahadevan S. (2000). Probability, Reliability and Statistical Methods in Engineering Design. John Wiley & Sons, New York, NY, USA.