DESIGNING AND DETAILING OF BUILDING SYSTEMS. MECHANICS IN CIVIL ENGINEERING

The theory of deformability calculation of timber joints on cylindrical nails

Vestnik MGSU 7/2015
  • Markovich Aleksey Semenovich - Moscow State University of Civil Engineering (MGSU) Candidate of Technical Sciences, Senior Lecturer, Department of Architectural and Construction Design, Moscow State University of Civil Engineering (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation; This e-mail address is being protected from spambots. You need JavaScript enabled to view it .

Pages 41-46

This article is devoted to the peculiarities of calculating deformability modifications of the timber elements on mechanical linkages. Here we analyze in detail the method of V.M. Kochenov used in the design standards of the Russian Federation. This method allows accurately determining the number of links that are able to resist the shear force in the linkage, however, this method does not include analyzing of shear deformation in modifications. And it is an important disadvantage. In this article the author considers another approach, based on the idea of determining the shear deformation of the mechanical linkage, installed in the connection. In order to calculate the shear deformations of the connections in the linkage it is necessary to conduct a preliminary analysis of the construction, to establish the type of connection and the thickness of the connected elements, to determine the number of slice planes, the number of established connections and the load level on the connection. After determining these values, structural analysis design is performed. This article describes in detail the theoretical aspects of this method, used assumptions and limitations. A test case is considered for validation of the considered methods.

DOI: 10.22227/1997-0935.2015.7.41-46

References
  1. SP 64.13330.2011. Derevyannye konstruktsii. Aktualizirovannaya redaktsiya SNiP II-25—80 [Requirements SP 64.13330.2011. Timber Constructions. The Actualized Edition of the Construction Norms SNiP II-25—80]. Moscow, Minregion Rossii Publ., 2011, 87 p. (In Russian)
  2. Posobie po proektirovaniyu derevyannykh konstruktsiy k SNiP II-25—80 [Guidelines on the Design of Timber Constructions to SNiP II-25—80]. Moscow, Stroyizdat Publ., 1986, 215 p. (In Russian)
  3. Kochenov V.M. Nesushchaya sposobnost’ elementov soedineniy derevyannykh konstruktsiy [Durability of Joining Elements of Timber Structures]. Moscow, Gosstroyizdat Publ., 1953, 320 p. (In Russian)
  4. Dmitriev P.A. Issledovanie dlitel’noy nesushchey sposobnosti soedineniy derevyannykh elementov na stal’nykh tsilindricheskikh nagelyakh [Investigation of Long-term Durability of Joints of Timber Elements on Steel Nails]. Izvestiya vysshikh uchebnykh zavedeniy. Stroitel’stvo i arkhitektura [News of Higher Educational Institutions. Construction and Architecture]. 1973, no. 5, pp. 28—35. (In Russian)
  5. Dmitriev P.A., Strizhakov Yu.D., Shvedov V.N. O raschete nesimmetrichnykh nagel’nykh soedineniy derevyannykh elementov so stal’nymi nakladkami i prokladkami // nagelyakh [On Calculation of Asymmetrical Nail Joints of Timber Elements with Steel Fish Plates and Linings]. Izvestiya vysshikh uchebnykh zavedeniy. Stroitel’stvo [News of Higher Educational Institutions. Construction]. 1999, no. 4, pp. 10—15. (In Russian)
  6. Shvedov V.N., Grokhotov A.B. Effektivnyy sposob soedineniy v derevyannykh konstruktsiyakh [Effective Method of Joints of Timber Constructions]. Povyshenie effektivnosti sel’skogo stroitel’stva : Mezhdunarodnyy sbornik trudov NGASU [Increase of Efficiency of Rural Construction. The international Collection of Works of NSUACE]. Novosibirsk, 2000, pp. 61—63. (In Russian)
  7. Rekomendatsii po ispytaniyu soedineniy derevyannykh konstruktsiy [Recommendations on Test of Joints of Timber Constructions]. Moscow, Stroyizdat Publ., 1980, 40 p. (In Russian)
  8. Gulvanessian H., Calgaro J.-A. Designers’ guide to Eurocode 0: Basis of Structural Design, 2nd edition. ISBN-10: 0727741713. ICE Publishing, 2012, 248 p.
  9. ISO 12491:1997. Statistical Methods for Quality Control of Building Materials and Components. ISO/TC 98/SC 2, Geneva, 1997, 30 p.
  10. Holicky M., Vorlicker M. General Lognormal Distribution in Statistical Quality Control. ICASP 7. Paris, 1995, pp. 719—724.
  11. Porteous A.J., Ross P. Designers’ Guide to Eurocode 5: Design of Timber Buildings. EN 1995-1-1. 978-0-7277-3162-3. Forthcoming: 2012, 220 p.
  12. BS 5268-2:2002. Structural Use of Timber. Code of Practice for Permissible Stress Design, Materials And Workmanship. BSI, London, 2002, 170 p.
  13. BS EN 408:2010+A1:2012. Timber Structures. Structural Timber and Glued Laminated Timber. Determination of Some Physical and Mechanical Properties. BSI, London, 2012. 42 p.
  14. Calgaro J.-A., Gulvanessian H., Holicky M. Bases de calcul des structures selon l’Eurocodes 0 : NF en 199. Paris, Le Moniteur Editions, 2013, 275 p.
  15. BS EN 912:2011. Timber Fasteners. Specifications for Connectors for Timbers. BSI, London, 2011, 52 p.
  16. Dias A.M.P.G., Cruz H.M.P., Lopes S.M.R., van de Kuilen J.W. Stiffness of Dowel-Type Fasteners In Timber — Concrete Joints. Proceedings of the ICE-Structures and Buildings. 2010, 163 (584), pp. 257—266.
  17. BS EN 13271:2002. Timber Fasteners. Characteristic Load-Carrying Capacities and Slip-Moduli for Connector Joints. BSI, London, 2002, 18 p.
  18. BS EN 1383:1999. Timber Structures. Test Methods. Pull-Through Resistance of Timber Fasteners. BSI, London, 1999, 8 p.
  19. DIN 1052—2008. Design of Timber Structures — General Rules and Rules for Buildings. 2008, 239 p.
  20. DIN 1052-10—2012. Design of Timber Structures — Part 10: Additional Provisions. 2012, 19 p.

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CALCULATION METHODS OF LATERALLY LOADED DRILLED SHAFTS IN ROCK

Vestnik MGSU 10/2015
  • Khokhlov Khokhlov Ivan Nickolaevich - Moscow State University of Civil Engineering (National Research University) (MGSU) postgraduate student, Department of Soil Mechanics and Geothechnics, Moscow State University of Civil Engineering (National Research University) (MGSU), 26 Yaroslavskoe shosse, Moscow, 129337, Russian Federation.

Pages 40-53

Today the design and calculation of pile foundations in rocks is poorly considered in the national regulatory and technical literature. It should be also noted that the need of taking into consideration the mechanical properties of rocky soils often occurs when designing structures for various purposes. The Requirements SP 24.13330.2011 “Pile foundations” in Appendix B (recommended) set out the calculation methodology of the combined effect of a horizontal force and torque of a single pile. The pile in this methodology is substituted by beam on an elastic foundation and the surrounding soil may be regarded as a linear-elastic deformable medium characterized by a coefficient of subgrade reaction. The manual for the design of pile foundations contains two calculation methods of piles for the combined effect of horizontal forces and torque (basic and tabular methods), which are based on considering the subgrade reaction on the side of a pile. Also this guide provides the guidance on calculation of single piles in rock under lateral loading. At the same time uniaxial compressive strength of intact rock is used as the main characteristics for rock massive. In general, the methods outlined in the manual are extensive explanation of the design methods with the examples of calculation, which is the development of the paragraph of the construction norms SNIP , which are now replaced by the actualized SP. In the analysis of the foreign experience of the design of drilled shafts in rock, there are three main groups of calculation methods of laterally loaded drilled shafts in rock: 1. Analytical methods based on the theory of elasticity; 2. Joint deformation of piles and soil with taking into account the non-linear subgrade reaction of soil (the so-called “p-y method”); 3. Numerical methods (FEM and DEM), which are implemented in a variety of special software computer systems. Among the first group of methods the following ones should be distinguished: Carter and Kulhawy (1992) and Zhang (2000). The “p-y” method was studied by Reese (1997). Poulos and Davis (1980) obtained solutions for piles using numerical methods. Randolph (1981) made a parametrical study of drilled shafts socketed into continuous elastic rock mass. The analysis of domestic and foreign calculation methods shows that there are no methods, which can be effectively applied both at the preliminary and detailed stage of the project. The majority of them require obtaining specific data, such as the coefficient of subgrade reaction along the length of the shaft or p-y deformation curves for a reliable estimation of shaft behavior in each case . However, today the materials on rock mechanics are accumulated and systematized, allowing to accurately enough determine the mechanical characteristics of the rock mass with a limited number of input data. Furthermore, the numerical modeling methods, having significant development and upgrading recently, can replace time-consuming and expensive field-testing. It is also worth considering that the numerical simulation can be effectively used on the stage of detailed calculations. In this preliminary study for the project design the use of numerical methods can be combined with the method of experimental design that allows getting the desired response function depending on several factors. Guided by this approach, the author carried out the study of the numerical models of laterally loaded drilled shafts in rock. Using 3D modeling and experimental design method the behavior of shafts was described depending on various factors. After processing of the results it is possible to obtain the parametric dependencies and nomograms. In this study, the parameters and the limits of their changes were chosen. In order to carry out the numerical experiment the matrix of experimental design was created that allows within the varied factors to obtain a mathematical relationship (response function) of bearing capacity of the shaft from three selected factors. The experiments and calculations allowed obtaining the dependence of bearing capacity of shaft from the set parameters: The checking of the adequacy of the equation shows the convergence of 2...9 % and it was conducted on the models with intermediate features within a selected factor space. The further processing and systematization of the obtained results is currently conducted, as well as the construction of nomograms after obtaining of parametric equations. The results of this study may be used for the preliminary assessment of the bearing capacity and deformation of laterally loaded drilled shafts in rocks. Using this technique it is also possible to reduce the number of field tests and increase their efficiency, reduce material consumption and the amount of shaft installation works, without decreasing of safety of the building.

DOI: 10.22227/1997-0935.2015.10.40-53

References
  1. Zertsalov M.G., Konyukhov D.S. O raschete svay v skal’nykh gruntakh [On Calculating Piles in Rock Soils]. Osnovaniya, fundamenty i mekhanika gruntov [Soil Mechanics and Foundation Engineering]. 2007. No. 1 (27). Pp. 8—12. (In Russian)
  2. Fedorovskiy V.G., Levachev S.N., Kurillo S.V., Kolesnikov Yu.M. Svai v gidrotekhnicheskom stroitel’stve [Piles in Hydraulic Engineering]. Moscow, ASV Publ., 2003, 240 p. (In Russian)
  3. Bezvolev S.G. Metodika opredeleniya koeffitsientov zhestkosti grunta pri raschete svay na gorizontal’nuyu nagruzku [Methods of Determining Soil Stiffness Coefficient at Calculating the Longitudinal Load of Piles]. Osnovaniya, fundamenty i mekhanika gruntov [Soil Mechanics and Foundation Engineering]. 2012, no. 2, pp. 8—12. (In Russian)
  4. Bakholdin B.V., Trufanova E.V. Nekotorye sravnitel’nye sopostavleniya rascheta svay na gorizontal’nuyu nagruzku s eksperimental’nymi dannymi [Some Comparisons of Longitudinal Load Calculation of Piles with Experimental Data]. Problemy mekhaniki gruntov i fundamentostroeniya v slozhnykh gruntovykh usloviyakh : trudy Mezhdunarodnoy nauchno-tekhnicheskoy konferentsii, posvyashchennoy 50-letiyu BashNIIstroy [Issues of Soil Mechanics and Foundation Engineering in Complicated Soil Conditions : Works of International Science and Technical Conference Dedicated to the 50th Anniversary of BashNIIstroy]. Ufa, 2006, vol. 3, pp. 18—22. (In Russian)
  5. Shishov I.I., Doshkov A.G. Raschet svai na deystvie vertikal’noy i gorizontal’noy sil [Calculation of Vertical and Horizontal Loading of Piles]. Vestnik Yuzhno-Ural’skogo gosudarstvennogo universiteta. Seriya: Stroitel’stvo i arkhitektura [Proceedings of South Ural State University. Series: Construction and Architecture]. 2007, no. 22 (94), pp. 67—68. (In Russian)
  6. Zhang L. Drilled Shafts in Rock. Analysis and Design. A.A. Balkema publishers, 2004, 383 p.
  7. Rock-socketed shafts for highway structure foundations. Transportation research board executive committee. NCHRP Synthesis 360, Washington, D.C., 2006, 137 p.
  8. Meyer B., Reese C. Analysis of Single Piles under Lateral Loading. Researchreport 244-1. Center for Highway Research, The University of Texas in Austin, Dec. 1979, 145 p.
  9. Nusairat J., Liang R.Y., Engel R.L. Design of Rock Socketed Drilled Shafts. Ohio Department of Transportation Research Final Report FHWA/OH-2006/21, 2006, 398 p.
  10. Pells P.J.N. State of Practice for the Design of Socketed Piles in Rock. Proceedings, 8th Australia New Zealand Conference on Geomechanics. Hobart, 2006, pp. 307—327.
  11. To A.C., Ernst H., Einstein H.H. Lateral Load Capacity of Drilled Shafts in Jointed Rock. Journal of Geotechnical and Geoenvironmental Engineering. ASCE. Aug. 2003, pp. 711—726. DOI: http://dx.doi.org/10.1061/(ASCE)1090-0241(2003)129:8(711).
  12. Chong W.L., Haque A., Ranjit P.G., Shahinuzamman A. A Parametric Study of Lateral Load Behavior of Single Piles Socketed into Jointed Rock Mass. Australian Geomechanics. March 2011, vol. 46, no. 1, pp. 43—50.
  13. Hegazy Y.A., Gushing A.G., Lewis C.J. Driven Pile Capacity in Clay and Drilled Shaft Capacity in Rock after Field Load Tests. Proceedings: Fifth International Conference on Case Histories in Geotechnical Engineering. New York, April 13—17 2004, 8 p.
  14. Drilled Shafts: Construction Procedures and Design Methods. Publication No FHWA-IF-99-025, US department of transportation, August 1999, 790 p.
  15. Foundation Design and Construction. The government of the Hong-Kong special administrative region, GEO Publication No. 1/2006, 376 p.

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