Currrent Issue: Volume 3, Number 4, 2015


Article

Implementing Vibration Framework for Simulation of VIV on Rigid Pier by SPH

1Department of Maritime Engineering, Amirkabir University of Technology, Tehran, Iran


American Journal of Civil Engineering and Architecture. 2015, 3(4), 137-143
doi: 10.12691/ajcea-3-4-4
Copyright © 2015 Science and Education Publishing

Cite this paper:
Hassan Ghassemi, Aliakbar Safaei, Shahryar Abtahi. Implementing Vibration Framework for Simulation of VIV on Rigid Pier by SPH. American Journal of Civil Engineering and Architecture. 2015; 3(4):137-143. doi: 10.12691/ajcea-3-4-4.

Correspondence to: Hassan  Ghassemi, Department of Maritime Engineering, Amirkabir University of Technology, Tehran, Iran. Email: gasemi@aut.ac.ir

Abstract

It is worth mentioning that the effect of waves on fixed and floating platforms is considered as an important element when designing any offshore structures. This paper is developed a numerical model to simulate current and wave interaction with a vertical cylinder as a platform leg using Smooth Particle Hydrodynamics (SPH) method for solving hydrodynamics part and using Finite Element Method (FEM) for structural part. SPH method is Lagrangian meshless based which is accurate enough for free surface modeling in comparison with other Eulerian mesh based methods. Capability of this method to calculate inline and cross flow forces on cylinder taking into consideration different time solution algorithms. The results showed that SPH not only creates much better result for simulating Vortex Induced Vibration (VIV) but also using the predictor-corrector algorithm for time step algorithm can leads to the most accurate results for predicting lift force.

Keywords

References

[1]  Smooth particle hydrodynamics: a review. Benz, W. In J.R. Buchler, editor, The Numerical Modeling of Nonlinear Stellar Pulsatations, pp. 269-288.Kluwer Academic Publishers, 1990. Cited in: Campbell, J.
 
[2]  Monaghan J. J .Siam, (1982), Why particle methods work. J. on Scientific and Statistical Computing, Vol 3(4), pp422-433.
 
[3]  Lucy, LB., Astron J.(1977), A numerical approach to the testing of the fission hypothesis, Astronomical Journal, vol. 82, Dec. 1977, p. 1013-1024.
 
[4]  Gingold, RA., Monaghan, J., Mon Not R Astron Soc,(1977) Smoothed particle hydrodynamics—theory and application to non-spherical stars, Vol.181, pp:375-389.
 
[5]  Monaghan, J. J. and Kocharyan,(1995) A SPH simulation of multi-phase flow, Computer Physics Communication, Vol.87, pp: 225-235.
 
Show More References
[6]  Panizzo, A. and Dalrymple, R. A.,(2004), “SPH modeling of underwater landslide generated waves” In Proc. 29th International Conference on Coastal Engineering, pp: 1147-1159.
 
[7]  Gomez-Gesteira, M. and Dalrymple, R. A., (2004), “Using a 3D SPH Method for Wave Impact on a Tall Structure”, J. Waterway, Port, Coastal and Ocean Engineering, Vol. 130(2), pp: 63-69.
 
[8]  Shao, S. and Gotoh, H.,(2004) “Simulating coupled motion of progressive wave and floating curtain wall by SPH-LES model”, Coastal Engineering Journal, Vol. 46(2), pp: 171-202.
 
[9]  Lee, E.S., Violeau, D., Benoit, M., Issa, R., Laurence, D., and Stansby, P.(2006), “Prediction of wave overtopping on coastal structures by using extended Boussinesq and SPH models”, In Proc. 30th International Conference on Coastal Engineering, pp: 4727-4740.
 
[10]  G R. Liu and M B. Liu., (2002). “Smooth Particle Hydrodynamic a mesh free particle method” World scientific publishing Co. Pte .Ltd. ISBN 981-238-456-1.
 
[11]  Crespo, A., (2008). “Application of the smoothed particle hydrodynamics model SPHysics to free surface hydrodynamics”, Ph.D. thesis, University of De Vigo.
 
[12]  Ostanek, J.K., Thole, K.A., 2012. Wake development in staggered short cylinder arrays within a channel. Exp. Fluids 53, 673-697.
 
[13]  Du, L., Jing, X., Sun, X., 2014. Modes of vortex formation and transition to three-dimensionalityin the wake of a freely vibrating cylinder. Journal o f Fluids and Structures 4 9, 554-573.
 
[14]  Nguyen, T., Koide, M., Yamada, S., Takahashi, T., Shirakashi, M., 2012. Influence of mass anddamping ratios on VIVs of a cylinder with a downstream counterpart in cruciform arrangement. Journal of Fluids and Structures 28, 40-55.
 
[15]  Huang, S., 2011. VIV suppression of a two-degree-of-freedom circular cylinder and dragreduction of a fixed circular cylinder by the use of helical grooves. Journal of Fluids and Structures 27, 1124-1133.
 
[16]  Sun, L., Zong, Z., Dong, J., Dong, G.H., Liu, C., 2012. Stripwise discrete vortex method for VIV analysis of flexible risers. Journal of Fluids and Structures 35,21-49.
 
[17]  Zhang, H., Fan, B., Chen, Z., Li, H., 2014. Numerical study of the suppression mechanism of vortex-induced vibration by symmetric Lorentz forces. Journal of Fluids and Structures 4 8, 62-80.
 
[18]  Chen, X., Xu, S., Yao, N., Shi, Y., 2010. 1.6 V Nanogenerator for mechanical energy harvesting using PZT nanofibers. Nano Letters 10, 2133-2137.
 
[19]  Grouthier, C., Michelin, S., Bourguet, R., Modarres-Sadeghi, Y., De Langre, E., 2014. On the efficiency of energy harvesting using vortex-induced vibrations of cables. Journal of Fluids and Structures 49, 427-4 40.
 
[20]  Quadrante, L.A .R., Nishi, Y., 2014. Amplification/suppression of flow-induced motions of an elastically mounted circular cylinder by attaching tripping wires. Journal of Fluids and Structures 48, 93-102.
 
[21]  Wang, J., Ran, J., Zhang, Z., 2014. Energy harvester based on the synchronization phenomenon of a circular cylinder. Mathematical Problems in Engine erring 2014, 1-9.
 
[22]  Facci, A .L., Porfiri, M., 2013. Analysis of three-dimensional effects in oscillating cantilevers immersed in viscous fluids. Journal of Fluids and Structures 38,205-222.
 
[23]  Grimaldi, E., Porfiri, M., Soria, L., 2012. Finite amplitude vibrations of a sharp-edged beam immersed in a viscous fluid near a solid surface. Journal of Applied Physics 112, 104 907.
 
[24]  Tafuni, A., Sahin, I., 2013. Hydrodynamic loads on vibrating cantilevers under a free surface in viscous fluids with SPH. In: Proceedings of the ASME 2 013International Mechanical Engineering Congress and Exposition (IMECE 2013), IMECE2013 63792.
 
[25]  Phan, C.N., Aureli, M., Porfiri, M., 2013. Finite amplitude vibrations of cantilevers of rectangular cross sections in viscous fluids. Journal of Fluids and Structures 40, 52-69.
 
[26]  De Rosis, A., 2014. Harmonic oscillations of laminae in non-Newtonian fluids: a lattice Boltzmann-Immersed Boundary approach. Advances in Water Resources 73, 97-107.
 
[27]  Intartaglia, C., Soria, L., Porfiri, M., 2014. Hydrodynamic coupling of two sharp-edged beams vibrating in a viscous fluid. Proceedings of the Royal Society of London: Mathematical, Physical and Engineering Sciences Series A 470, 20130397.
 
[28]  De Rosis, A., 2014. Harmonic oscillations of laminate in non-Newtonian fluids: a lattice Boltzmann-Immersed Boundary approach. Advances in Water Resources 73, 97-107.
 
[29]  ANSYS USER MANUA, 2014.
 
[30]  Sangita,M. Computation of Solitary Waves During Propagation and Run up on a Slope. J. Ocean Engineering, Volume 26, Issue 11, Pages 1063-1083, November 1999.
 
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Article

The Upshot of the 2012 Flooding on Structural Components and Fabrics of Buildings at Ogbaru, Anambra State Nigeria

1Department of Building, Nnamdi Azikiwe University, Awka, Nigeria

2Department of Quantity Surveying, Nnamdi Azikiwe University, Awka, Nigeria


American Journal of Civil Engineering and Architecture. 2015, 3(4), 129-136
doi: 10.12691/ajcea-3-4-3
Copyright © 2015 Science and Education Publishing

Cite this paper:
Ezeokoli F. O., Okoye P. U., Ugochukwu S. C.. The Upshot of the 2012 Flooding on Structural Components and Fabrics of Buildings at Ogbaru, Anambra State Nigeria. American Journal of Civil Engineering and Architecture. 2015; 3(4):129-136. doi: 10.12691/ajcea-3-4-3.

Correspondence to: Okoye  P. U., Department of Building, Nnamdi Azikiwe University, Awka, Nigeria. Email: pu.okoye@unizik.edu.ng

Abstract

The study examined the effect of the 2012 flooding on structural components and fabrics of buildings at Ogbaru Local Government Area of Anambra State. It also examined the heights of the ground floors and foundations of the buildings respectively in relation to the height of the flood. Questionnaire survey on the selected households and physical examination on the building structures were carried out. The study revealed that most buildings in the area were either fully or partially submerged during the flood incidence. it further revealed that there no very severe damages on the structural components of the buildings, despite that most of the buildings have low ground floor levels (74%) and shallow foundations (68%) below 300mm. However, building fabrics and elements such as finishes and electrical fittings were severely damaged when the flood height rose 1 metre above the ground floor level. More so, the study revealed that the flood severely damaged both the structural components and fabrics of very old, weak and mud buildings. Based on this, the study recommended that building constructors in the area should raise the ground floor level of their building projects to at least 1 metre above the ground level. It also recommended suspension of buildings on plinths and use of deep stripe or raft foundation. The use water resistant materials and components such as paints, doors, windows and electrical fittings and incorporation of oversite concrete as floors while building new structures or refurbishing existing ones are also recommended.

Keywords

References

[1]  Ofori, G., Construction industry development for disaster prevention and response, Singapore University Press, Singapore, 2006.
 
[2]  Adedeji, O.H., Odufuwa, B.O. and Adebayo, O.H., “Building capabilities for flood and hazard preparedness and risk reduction in Nigeria: need for spatial planning and land management,” Journal of sustainable Development in Africa, 14 (1), 45-58, 2012.
 
[3]  Haigh, R., “Developing a resilience built environment: post-disaster reconstruction as a window of opportunity,” International Conference on sustainable environments (ICSBE,) Kandy, Dec. 13-14, 2010.
 
[4]  Linham, M. M. and Nicholls, R.J., “Technologies for climate change adaptation – coastal erosion and flooding,” UNEP Risø Centre on Energy, Climate and Sustainable Development Risø DTU National Laboratory for Sustainable Energy, Roskilde Denmark, 2010. Available: http://www.uneprisoe.org/ http://tech-action.org/ [Accessed November 5, 2014].
 
[5]  Schramn, D. and Dries, R., Natural Hazard; causes and effects, University of Wisconson, U.S.A, 1986.
 
Show More References
[6]  Nwilo, P.C., “Geospatial information in flooding and disaster management in Nigeria,” 7th Annual Lecture of Faculty of Environmental Sciences Nnamdi Azikiwe University, Awka, Nigeria, 2013.
 
[7]  Don Okpala, V.U., “The environmental effects of flood disaster in Anambra state,” Advances in Applied Science Research, 4(1), 499-505, 2013. [Online]. Available: www.pelagiaresearchlibrary.com [Accessed September 26, 2014].
 
[8]  Ezeabasili, A.C.C. and Okonkwo, A.U., “Climate change impacts on the built environment in Nigeria,” African Research Review, 7(4), 288-303, 2013.
 
[9]  National Emergency Management Agency (NEMA), “Annual report on flood,” Official Gazette, Abuja, 2012.
 
[10]  Ajaero, C.K. and Mozie, A.T., “Socio-demographic differentials in vulnerability to flood disasters in rural Southeastern Nigeria,” International Seminar on Demographic Differential Vulnerability to Natural Disasters in the Context of Climate Change Adaptation organised by IUSSP in collaboration with Chulalongkorn University Bangkok and the Wittgenstein Centre for Demography and Global Human Capital (IIASA, VID/OAW,WU) held in Kao Lak, Thailand, 23-25 April, 2014.
 
[11]  Nigerian Meteorological Agency (NIMET), Nigerian Meteorological Agency (NIMET) 2012 seasonal rainfall prediction & socio-economic implications for Nigeria, 2012.
 
[12]  Jha, A., Lamond, J., Bloch, R., Bhattacharya, N., Lopez, A., Papachristodoulou, N., Bird, B., Proverbs, D., Davies, J. and Barker, R., Five feet high and rising cities and flooding in the 21st century,” Policy Research Working Paper, The World Bank East Asia and Pacific Region Transport, Energy & Urban Sustainable Development Unit, 2011.
 
[13]  CIRIA, Improving the flood performance of new buildings flood resilient construction, RIBA Publishing, London, UK, 2007.
 
[14]  United Nations Office for the Coordination of Humanitarian Affairs (OCHA), “Nigeria: Floods Situation Report No. 2 (as of 15 November 2012),” Report of OCHA Humanitarian Advisory team in Nigeria in collaboration with humanitarian partners, 2012. www.ochaonline.un.org/rowca
 
[15]  Anambra State Government (ANSG), “Anambra State Flood Disaster Relief Coordinating Committee Interim Report 1,” Anambra Forum, 2012.
 
[16]  Anambra State Emergency Management Agencies (ANSEMA), “Report on flood in Anambra state,” Official Report, Awka, 2012.
 
[17]  Efobi, K. and Anierobi, C., “Impact of flooding on riverine communities: the experience of the Omambala and other areas in Anambra State, Nigeria,” Journal of Economics and Sustainable Development, 4(18), 58-63, 2013.
 
[18]  Monanu, P.C., “Temperature and sunshine,” in Ofomata, G.E.K.(ed), Nigeria in Maps: Eastern States, Ethiope Publishing House, Benin City, 16-18, 1975a.
 
[19]  Monanu, P.C., “Humidity,” in Ofomata, G.E.K.(ed), Nigeria in Maps :Eastern States, Ethiope Publishing House, Benin City, 19-21, 1975b.
 
[20]  Ezenwaji E.E., Orji M.U., Enete, C.I. and Ahiadu, H.O., “The effect of climate change on the communities of Ogbaru Wetland of South West Anambra State, Nigeria,” New York Science Journal, 7(10), 68 - 74, 2014. http://www.sciencepub.net/newyork
 
[21]  National Population Commission (NPC), “Population census figures for 2006,” Official Gazette, Abuja, 2006.
 
[22]  Cochran, W. G., Sampling techniques, (3rd ed.), John Wiley & Sons, New York, 1977.
 
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Article

Traditional vs FEA Based Analysis/Design of Baseplates for Tall Telecommunication & Transmission Poles

1Senior Consulting Engineer, B&V, Canada

2City University, London, UK


American Journal of Civil Engineering and Architecture. 2015, 3(4), 118-128
doi: 10.12691/ajcea-3-4-2
Copyright © 2015 Science and Education Publishing

Cite this paper:
Tahir Kibriya, Leena Tahir. Traditional vs FEA Based Analysis/Design of Baseplates for Tall Telecommunication & Transmission Poles. American Journal of Civil Engineering and Architecture. 2015; 3(4):118-128. doi: 10.12691/ajcea-3-4-2.

Correspondence to: Tahir  Kibriya, Senior Consulting Engineer, B&V, Canada. Email: t_kibriya@yahoo.com

Abstract

Various shapes of steel poles are commonly used in the telecommunications and transmission industry for carrying telecommunication equipment to transmit signals for communication equipment or wires and power equipment like transformers etc. for power transmission purposes. These poles vary from 50’ to almost 500’ heights with winds being the governing loads in addition to superimposed equipment loads and snow/ice loads and hence require careful design. The poles vary from being round in geometry to 8/12/16/24/28 sided shapes. With large base diameters and appreciable moments and direct loads, typically the pole baseplates are round, hexagonal or square with/without stiffeners and either rest on the supporting anchor rod base nuts or on grout over the base support, all of which require different analysis/ design procedures. From the literature, one can observe that while baseplate analysis and design for large poles structures has not been amply investigated, limited investigations and testing carried out on base plates designed by various methods and most test results have indicated most procedures to be under designing plates. While AISC and ASCE 48 codes provide limited guidance on design of these various types of pole baseplates, ANSI/EIA/TIA 222F & 222G codes merely refer to AISC for design of these different configurations of baseplates. Many proprietary base plate analysis/design worksheets commercially available produce different results. With the availability of advanced structural analysis techniques like FEA, a comparison is made between the baseplates designed by typical methods using commercially available baseplate worksheets and those designed by using the FEA techniques. The analysis results vary appreciably between the traditional methods and the FEA based method. This paper analyses few pole base plates based on FEA and compares them with the baseplates designed by traditional methods and suggests appropriate improvements in the current design/ analysis procedures so as to reduce the appreciable differences between the both procedures.

Keywords

References

[1]  ANSI/ TIA 222G – 2005, Structural Standard for Antenna Supporting Structures and Antennas, EIA/ TIA, 2005.
 
[2]  ANSI/ TIA/ EIA – 222F – 1996, Structural Standards for Steel Antenna Towers and Antenna Supporting Structures, TIA/ EIA, 1996.
 
[3]  AISC Steel Design Guide 1 – Base Plate and Anchor Rod Design, AISC, 2006.
 
[4]  Horn, Daniel, Technical Manual 1, Design of Monopole Bases, Concepts Inc., 2004.
 
[5]  ASCE/SEI 48-05, Design of Steel Transmission Poles, ASCE/ SEI, 2011.
 
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[6]  Honek, William C. & Westphal, Derek, Practical Design and Detailing of Steel Column Base Plates, Forell Elsesser Engineers Inc., July, 1999.
 
[7]  Chabbra, Surendra J., Column Base Plate Design Table, Engineering Journal, AISC, 2003 pp 12-20.
 
[8]  Drake, Richard M. & Elkin, Sharon J., Beam-Column Base Plate Design - LRFD Method, Engineering Journal, AISC, First Quarter, 1999.
 
[9]  Timoshenko, S. & Woinowsky-Krieger, S., Theory and Design of Plates and shells, 2nd Ed, McGraw Hill, 1976.
 
[10]  Young, Warren C. & Budynas, Richard G. Roark’s Formulas for Stress & Strain, 7th Ed. McGraw Hill, 2002.
 
Show Less References

Article

Adfreeze Forces on Lightly Loaded Pile Foundations of Solar PV Farms in Cold Regions

1Senior Consulting Engineer, Black &Veatch, Toronto, Canada

2MSc Structural Engineering, City University, London, UK


American Journal of Civil Engineering and Architecture. 2015, 3(4), 109-117
doi: 10.12691/ajcea-3-4-1
Copyright © 2015 Science and Education Publishing

Cite this paper:
Kibriya T., Tahir L.. Adfreeze Forces on Lightly Loaded Pile Foundations of Solar PV Farms in Cold Regions. American Journal of Civil Engineering and Architecture. 2015; 3(4):109-117. doi: 10.12691/ajcea-3-4-1.

Correspondence to: Kibriya  T., Senior Consulting Engineer, Black &Veatch, Toronto, Canada. Email: t_kibriya@yahoo.coml

Abstract

Renewable energy generation through utility scale ground mounted solar photo-voltaic systems has gained steady popularity with increasing number of such facilities being constructed in various regions worldwide. Solar PV systems are very popular in the province of Ontario in Canada and strong growth in this sector is led by the popular initiatives of the Government of Ontario which offers extremely attractive rates for generation of renewable energy through Ontario Hydro’s popular Feed-In Tariff (FIT) Program. Many other countries offer incentives on such generation of renewable energy while many governments aim at increasing the percentages of renewable energy in their systems tremendously. Most ambitious plan has recently been launched by the state of Hawaii to deploy 100% of renewable energy in their grid by 2045. Solar PV systems are a cheap source of renewable energy as the energy released by the sun is harnessed as electricity by the solar photo-voltaic panels which is fed to the main transmission systems after raising its voltage. The costs of solar photo-voltaic panels meanwhile have also kept downward trends while the manufacture of various types of solar panels has multiplied rapidly. These renewable energy generation facilities are fully sustainable being completely recyclable on completion of their design/ contract period. Typical utility scale ground mounted solar PV facilities usually comprise of solar PV panels mounted on series of racking tables supported on foundations mostly comprising of partially embedded steel pipes. The governing loads for the foundations of these lightly loaded solar PV structures are usually frost loads in areas facing extremely cold winters. In fine grained soils like silty/ clayey soils, large adfreeze stresses develop due to penetrating frost deep into the soil resulting into uplift of foundation piles. Typical winter conditions in Ontario are harsh with extreme frost conditions in most areas which poses unique issues for design and construction of such foundations. Being a relatively newer technology, codes and standards for design and testing of such lightly loaded solar PV structures are still in the formulation stages. Frost heaving and its effects often create adverse conditions for these structures thereby affecting the production and continuous supply of renewable energy. Due to larger depths of frost penetration in extreme winter conditions, understanding the action of frost and related development of adfreeze stresses on these lightly loaded pile foundations is extremely important. Calculating reasonable frost depths and thereby the design loads is an important part of pile design for such facilities while the contractors tend to save on pile lengths to save on costs and compromising the structural design. Many such Solar PV facilities have experienced frost uplift of foundation piles either during the construction phase or during its lifetime. Since frost heave is more of a serviceability related issue, unfactored adfreeze loads without any factor of safety is a usual tendency by the EPC contractors. This paper investigates the frost depths and adfreeze stress related issues with the foundation piles of solar PV facilities hence the governing design forces on these piles and suggests appropriate frost related design stresses for the foundation piles. The authors have been heavily involved in design/ design reviews, pile selection/ design and pile load testing in the majority of the solar PV farms in Canada and US along with rehabilitation of piles affected by frost [1,2,3].

Keywords

References

[1]  Kibriya, T., Racking Foundation Piles Design and Testing Review Report for Various Solar PV Farms in Ontario, 2013.
 
[2]  Kibriya, T., Construction Issues Faced By Renewable Energy Production Facilities – Solar PV Farms in Ontario, Canada, Standard Scientific Research and Essays Vol1 (14): 391-397, December 2013.
 
[3]  Kibriya T. & Tahir L., Renewable Energy Generation - Critical study on design of pile foundations for Solar Photovoltaic (PV) ground mounted systems in Ontario, Canada, Standard Scientific Research and Essays Vol. 3(3): 056-065, March, 2015.
 
[4]  Pewe, Troy L. & Paige, Russell A., Frost Heaving of Piles with an Example from Fairbanks, Alaska, Geological Survey Bulletin 1111-1, 1963.
 
[5]  Canadian Geotechnical Society, Canadian Foundation Engineering Manual, 4th Edition, 2006.
 
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[6]  Penner. E., Uplift Forces on foundations in frost heaving soils, Canadian Geotechnical Journal, Volume 11, No.3, 1974.
 
[7]  Penner, E. & Goodrich, L.E., Adfreezing Stresses on Steel Piles, Thompson, Manitoba, Proceeding of Fourth International Conference – Permafrost, Fairbanks, Alaska, July 17-22, 1983.
 
[8]  Department of Army and Air Force, TM5-852-4, Arctic and Sub-Arctic Construction - Foundations for Structures, October, 1983.
 
[9]  Sailors Engineering Associates, Adfreeze Bond Reduction by Slick-coat Friction Reduction Epoxy Coating, Georgia, USA.
 
[10]  Parmesvaran, V.R., Table 1, Adfreeze strength of piles in ice with varying loading rates, Adfreeze strength of model piles in ice, Canadian Geotech. J. Vol. 18. 1981.
 
[11]  Hiroshi S., Mechanical properties between ice and various materials used in hydraulic structures. Int. Journal for. Offshore and Polar Engg. Vol. 21, No. 2. 2011.
 
[12]  Domaschuk, L., (1982). Frost heave forces on embedded structural units, Department of Civil Engineering, University of Manitoba, Winnipeg, Canada, Proceedings of the 4th Canadian Permafrost Conference, National Research Council, Canada 1982.
 
[13]  Volokhov, S.S., The role of the zone of contact of frozen soils with foundation materials in the formation of adfreezing strengths, Permafrost – Seventh International Conference, Yellowknife, Canada, Collection Nordicana # 55.
 
[14]  ASTM, D3689, Standard Test Methods for Deep Foundations under Static Axial Tensile Load, 2007.
 
[15]  ASTM, D1143, Standard Test Methods for Deep Foundations under Static Axial Compressive Load, 2007.
 
[16]  ASTM, D3966, Standard Test Methods for Deep Foundations under Lateral Load, 2007.
 
Show Less References