Проектирование свайных фундаментов для сейсмостойких зданий и сооружений главным образом основывается на анализе сейсмической реакции слоистых разжиженных грунтов. В данной статье рассматривается реакция свай на интенсивные сейсмические нагрузки во время землетрясений в г. Кобе (Япония, о-в Хонсю, 1995 г.) и г. Апленд (США, штат Калифорния,

1990 г.), которые сопровождались повышением порового давления. Авторами использовался программный комплекс PLAXIS 3D со структурной нелинейной гипопластической моделью грунта, описывающего как разжижающиеся, так и не разжижающиеся грунты при воздействии двух землетрясений разной природы, что дает возможность более глубокого подхода к изучению динамической реакции взаимодействия оснований и сооружений. Гипопластическая структурная модель, примененная для изучения работы свай в водонасыщенных и сухих грунтах, адекватно описывает нелинейное поведение песчаных грунтов в плотном и рыхлом сложении. Отмечается, что для использования модели требуются несколько параметров, которые получаются в ходе стандартных лабораторных испытаний. Модель может реализовать работу грунта при различных напряжениях и плотностях, при этом используя один и тот же набор свойств. Изучено влияние длины свай и расстояния между ними, а также частоты сейсмического воздействия на поведение свайных кустов фундаментов в сухих и водонасыщенных грунтовых условиях. Полученные в ходе исследования данные показали, что инженерно-геологические условия, диаметр и длина свай, а также активизация движения грунта оказывают значительное влияние на динамическую реакцию слоистого разжиженного грунта на площадке. Сопротивление трения вдоль ствола сваи сильно уменьшается, особенно в условиях водонасыщенности. Под воздействием движений грунта, вызванных землетрясениями, увеличение длины свай до соотношения L/D = 55 от начального L/D = 35 привело к возникновению максимального изгибающего момента в сваях примерно 52 и 19% для первого случая и приблизительно 62 и 23% — для второго.

Подготовлена главным редактором журнала А.Г. Шашкиным.

1. Albusoda B.S., 2016. Engineering assessments of liquefaction potential of Baghdad soil under dynamic loading. Journal of Engineering and Development, Vol. 20, No. 1, pp. 59–76.
2. Albusoda B.S., Alahmar M.M., 2014. The behavior of gypseous soil under vertical vibration loading. Journal of Engineering, Vol. 20,
No. 1, pp. 21–30.
3. Albusoda B.S., Almashhadany O.Y., 2014. Effect of allowable vertical load and length/diameter ratio (L/D) on behavior of pile group subjected to torsion. Journal of Engineering, Vol. 20, No. 12, pp. 13–31, https://doi.org/10.31026/j.eng.2014.12.02.
4. Alfach M., 2012. Influence of soil plasticity on the seismic performance of pile foundation — a 3D numerical analysis. Jordan Journal of Civil Engineering, Vol. 6, No. 4, pp. 394–409.
5. Al-Jeznawi D., Jais I.B.М., Albusoda B.S., 2022. The effect of model scale, acceleration history, and soil condition on closed-ended pipe pile response under coupled static-dynamic loads. International Journal of Applied Science and Engineering, Vol. 19, No. 2,
ID 2022018, https://doi.org/10.6703/IJASE.202206_19(2).007.
6. Al-Jeznawi D., Jais I.B.М., Albusoda B.S., Khalid N., 2022. The slenderness ratio effect on the response of closed-end pipe piles in liquefied and nonliquefied soil layers under coupled static-seismic loading. Journal of the Mechanical Behavior of Materials, Vol. 31, No. 1, pp. 83–89, https://doi.org/10.1515/jmbm-2022-0009.
7. Al-Jeznawi D., Jais I.B.М., Albusoda B.S., Alzabeebee S., Keawsawasvong S., Khalid N., 2023. Numerical study of the seismic response of closedended pipe pile in cohesionless soils. Transportation Infrastructure Geotechnology, Vol. 11, pp. 63–89, https://doi.org/10.1007/s40515-022-00273-z.
8. Al-Taie A.J., Albusoda B.S., 2019. Earthquake hazard on Iraqi soil: Halabjah earthquake as a case study. Geodesy and Geodynamics, Vol. 10, No. 3, pp. 196–204, https://doi.org/10.1016/j.geog.2019.03.004.
9. Anaraki K.E., 2008. Hypoplasticity investigated: parameter determination and numerical simulation. MS Thesis, Delft University of Technology, Delft, Netherlands.
10. Bühler M.M., Cudmani R.O., Osinov V.A., Libreros-Bertini A.B., Gudehus G., 2003. Experimental and numerical investigation of the influence of local site conditions on the ground motion during strong earthquakes. Proceedings of the International Symposium on geotechnical measurements and modelling, Karlsruhe, Germany, 2003, pр. 441–449.
11. Chatterjee K., Choudhury D., Poulos H.S., 2015. Seismic analysis of laterally loaded pile under influence of vertical loading using finite element method. Computers and Geotechnics, Vol. 67, рр. 172–186, https://doi.org/10.1016/j.compgeo.2015.03.004.
12. Choudhury D., Chatterjee K., Kumar A., Phule R.R., 2014. Pile foundations during earthquakes in liquefiable soils — theory to practice. Proceedings of the 15th Symposium on earthquake engineering, Roorkee, India, 2014, pp. 327–342, https://doi.org/10.13140/2.1.3796.3847.
13. Fattah M.Y., Zabar B.S., Mustafa F.S., 2017. Effect of saturation on response of a single pile embedded in saturated sandy soil to vertical vibration. European Journal of Environmental and Civil Engineering, Vol. 24, No. 3, pp. 381–400, https://doi.org/10.1080/19648189.2017.1391126.
14. Fattah M.Y., Zbar B.S., Mustafa F.S., 2021. Effect of soil saturation on load transfer in a pile excited by pure vertical vibration. Structures and Buildings, Vol. 174, No. 2, pp. 132–144, https://doi.org/10.1680/jstbu.16.00206.
15. Hussein R.S., Albusoda B.S., 2021. Experimental and numerical analysis of laterally loaded pile subjected to earthquake loading. In book M.O. Karkush, D. Choudhury (eds), Modern applications of geotechnical engineering and construction, pp. 291–303, https://doi.org/10.1007/978-981-15-9399-4_25.
16. Hussien R.S., Albusoda B.S., 2023. Experimental modeling of a single pile in liquefiable soil under the effect of coupled static-dynamic loads. Innovative Infrastructure Solutions, Vol. 8, ID 50, https://doi.org/10.1007/s41062-022-01017-1.
17. Herle I., Gudehus G., 1999. Determination of parameters of a hypoplastic constitutive model from properties of grain assemblies. Mechanics of Cohesive-Frictional Materials, Vol. 4, No. 5, pp. 461–486, https://doi.org/10.1002/(SICI)1099-1484(199909)4:53.0.CO;2-P.
18. Jawad A.S., Albusoda B.S., 2022. Numerical modeling of a pile group subjected to seismic loading using the hypoplasticity model. Engineering, Technology and Applied Science Research, Vol. 12, No. 6, pp. 9771–9778, https://doi.org/10.48084/etasr.5351.
19. Jimenez G.A.L., Dias D., Jenck O., 2019. Effect of layered liquefiable deposits on the seismic response of soil foundations-structure systems. Soil Dynamics and Earthquake Engineering, Vol. 124, pp. 1–15, https://doi.org/10.1016/j.soildyn.2019.05.026.
20. Kolymbas D., 1985. A generalized hypoelastic constitutive law. Proceedings of 11th International Conference on Soil Mechanics and Foundation Engineering, Vol. 5, San Francisco, USA, 1985, ID 2626.
21. Limnaiou T.G., Papadimitriou A.G., 2022. Verification of bounding surface plasticity model with reversal surfaces for the analysis of liquefaction problems. Soil Dynamics and Earthquake Engineering, Vol. 163, ID 107394, https://doi.org/10.1016/j.soildyn.2022.107394.
22. Ramirez J., Barrero A.R., Chen L., Dashti S., Ghofrani A., Taiebat M., Arduino P., 2018. Site response in a layered liquefiable deposit: evaluation of different numerical tools and methodologies with centrifuge experimental results. Journal of Geotechnical and Geoenvironmental Engineering, Vol. 144, No. 10, ID 04018073, https://doi.org/10.1061/(ASCE)GT.1943-5606.0001947.
23. Shen Y., Zhong Z., Li L., Du X., 2022. Nonlinear solid-fluid coupled seismic response analysis of layered liquefiable deposit. Journal of Applied Sciences, Vol. 12, No. 11, ID 5628, https://doi.org/10.3390/app12115628.
24. Ter-Martirosyan A., Le D.A., 2020. Calculation of the settlement of pile foundations taking into account the influence of soil liquefaction. IOP Conference Series Materials Science and Engineering, Vol. 869, No. 5, ID 052025, https://doi.org/10.1088/1757-899X/869/5/052025.
25. Wang R., Fu P., Zhang J.M., 2016. Finite element model for piles in liquefiable ground. Computers and Geotechnics, Vol. 72, No. 5,
pp. 1–14, https://doi.org/10.1016/j.compgeo.2015.10.009.
26. Wu W., Bauer E., Kolymbas D., 1996. Hypoplastic constitutive model with critical state for granular materials. Mechanics of Materials, Vol. 23, No. 1, pp. 45–69.

АЛЬ-ДАМЛУЖДИ О.АЛЬ-Ф.С.*
Багдадский университет, г. Багдад, Ирак
Адрес: Аль-Джадрия, г. Багдад, 10071, Ирак
ДЖАВАД А.С.
Багдадский университет, г. Багдад, Ирак, a.jawad1901p@coeng.uobaghdad.edu.iq
АЛБУЗОДА Б.С.
Багдадский университет, г. Багдад, Ирак, dr.bushra_albusoda@coeng.uobaghdad.edu.iq

The seismic design of pile foundations relies mainly on the analysis of seismic response of layered, liquefiable locations. The seismic response of piles to the intense motions of Kobe and Upland earthquakes which occur with the developing high pore water pressures are studied in this paper. PLAXIS 3D software is utilized with a non linear soil constitutive model, the hypoplastic one, for both liquefiable and non-liquefiable soils under the impact of two earthquakes’ motions of different features to give a complete understanding of the dynamic soil-structure interaction response. The hypoplasticity constitutive model used for researching pile behavior in saturated and dry soils can adequately describe non-linear behavior of loose and dense sandy soils. It has been mentioned that the model application requires several parameters which are obtained during conventional laboratory tests, the model can implement soil behavior at different stresses and densities using the same set of material properties. The influence of a pile length, an inter-pile distance as well as a frequency of seismic action on seismic behavior of pile foundation systems in dry and saturated soil conditions have been studied. The findings from this study shows that the site profile, pile diameter, pile length, and excitation of ground motion significantly affect the dynamic response of the layered liquefiable site. The frictional resistance along the pile greatly decreases,    particularly in the saturated condition. Under the influence of the motion caused by the earthquakes increasing the length of the piles to L/D = 55 from the initial length L/D = 35 increases the maximum bending moment of the piles by about 52 and 19% for the first case, and by about 62 and 23% for the second one.

1. Albusoda B.S., 2016. Engineering assessments of liquefaction potential of Baghdad soil under dynamic loading. Journal of Engineering and Development, Vol. 20, No. 1, pp. 59–76.
2. Albusoda B.S., Alahmar M.M., 2014. The behavior of gypseous soil under vertical vibration loading. Journal of Engineering, Vol. 20,
No. 1, pp. 21–30.
3. Albusoda B.S., Almashhadany O.Y., 2014. Effect of allowable vertical load and length/diameter ratio (L/D) on behavior of pile group subjected to torsion. Journal of Engineering, Vol. 20, No. 12, pp. 13–31, https://doi.org/10.31026/j.eng.2014.12.02.
4. Alfach M., 2012. Influence of soil plasticity on the seismic performance of pile foundations — a 3D numerical analysis. Jordan Journal of Civil Engineering, Vol. 6, No. 4, pp. 394–409.
5. Al-Jeznawi D., Jais I.B.М., Albusoda B.S., 2022. The effect of model scale, acceleration history, and soil condition on closed-ended pipe pile response under coupled static-dynamic loads. International Journal of Applied Science and Engineering, Vol. 19, No. 2,
ID 2022018, https://doi.org/10.6703/IJASE.202206_19(2).007.
6. Al-Jeznawi D., Jais I.B.М., Albusoda B.S., Khalid N., 2022. The slenderness ratio effect on the response of closed-end pipe piles in liquefied and nonliquefied soil layers under coupled static-seismic loading. Journal of the Mechanical Behavior of Materials, Vol. 31, No. 1, pp. 83–89, https://doi.org/10.1515/jmbm-2022-0009.
7. Al-Jeznawi D., Jais I.B.М., Albusoda B.S., Alzabeebee S., Keawsawasvong S., Khalid N., 2023. Numerical study of the seismic response of closedended pipe pile in cohesionless soils. Transportation Infrastructure Geotechnology, Vol. 11, pp. 63–89, https://doi.org/10.1007/s40515-022-00273-z.
8. Al-Taie A.J., Albusoda B.S., 2019. Earthquake hazard on Iraqi soil: Halabjah earthquake as a case study. Geodesy and Geodynamics, Vol. 10, No. 3, pp. 196–204, https://doi.org/10.1016/j.geog.2019.03.004.
9. Anaraki K.E., 2008. Hypoplasticity investigated: parameter determination and numerical simulation. MS Thesis, Delft University of Technology, Delft, Netherlands.
10. Bühler M.M., Cudmani R.O., Osinov V.A., Libreros-Bertini A.B., Gudehus G., 2003. Experimental and numerical investigation of the influence of local site conditions on the ground motion during strong earthquakes. Proceedings of the International Symposium on geotechnical measurements and modelling, Karlsruhe, Germany, 2003, pр. 441–449.
11. Chatterjee K., Choudhury D., Poulos H.S., 2015. Seismic analysis of laterally loaded pile under influence of vertical loading using finite element method. Computers and Geotechnics, Vol. 67, рр. 172–186, https://doi.org/10.1016/j.compgeo.2015.03.004.
12. Choudhury D., Chatterjee K., Kumar A., Phule R.R., 2014. Pile foundations during earthquakes in liquefiable soils — theory to practice. Proceedings of the 15th Symposium on earthquake engineering, Roorkee, India, 2014, pp. 327–342, https://doi.org/10.13140/2.1.3796.3847.
13. Fattah M.Y., Zabar B.S., Mustafa F.S., 2017. Effect of saturation on response of a single pile embedded in saturated sandy soil to vertical vibration. European Journal of Environmental and Civil Engineering, Vol. 24, No. 3, pp. 381–400, https://doi.org/10.1080/19648189.2017.1391126.
14. Fattah M.Y., Zbar B.S., Mustafa F.S., 2021. Effect of soil saturation on load transfer in a pile excited by pure vertical vibration. Structures and Buildings, Vol. 174, No. 2, pp. 132–144, https://doi.org/10.1680/jstbu.16.00206.
15. Hussein R.S., Albusoda B.S., 2021. Experimental and numerical analysis of laterally loaded pile subjected to earthquake loading. In book M.O. Karkush, D. Choudhury (eds), Modern applications of geotechnical engineering and construction, pp. 291–303, https://doi.org/10.1007/978-981-15-9399-4_25.
16. Hussien R.S., Albusoda B.S., 2023. Experimental modeling of a single pile in liquefiable soil under the effect of coupled static-dynamic loads. Innovative Infrastructure Solutions, Vol. 8, ID 50, https://doi.org/10.1007/s41062-022-01017-1.
17. Herle I., Gudehus G., 1999. Determination of parameters of a hypoplastic constitutive model from properties of grain assemblies. Mechanics of Cohesive-Frictional Materials, Vol. 4, No. 5, pp. 461–486, https://doi.org/10.1002/(SICI)1099-1484(199909)4:53.0.CO;2-P.
18. Jawad A.S., Albusoda B.S., 2022. Numerical modeling of a pile group subjected to seismic loading using the hypoplasticity model. Engineering, Technology and Applied Science Research, Vol. 12, No. 6, pp. 9771–9778, https://doi.org/10.48084/etasr.5351.
19. Jimenez G.A.L., Dias D., Jenck O., 2019. Effect of layered liquefiable deposits on the seismic response of soil foundations-structure systems. Soil Dynamics and Earthquake Engineering, Vol. 124, pp. 1–15, https://doi.org/10.1016/j.soildyn.2019.05.026.
20. Kolymbas D., 1985. A generalized hypoelastic constitutive law. Proceedings of 11th International Conference on Soil Mechanics and Foundation Engineering, Vol. 5, San Francisco, USA, 1985, ID 2626.
21. Limnaiou T.G., Papadimitriou A.G., 2022. Verification of bounding surface plasticity model with reversal surfaces for the analysis of liquefaction problems. Soil Dynamics and Earthquake Engineering, Vol. 163, ID 107394, https://doi.org/10.1016/j.soildyn.2022.107394.
22. Ramirez J., Barrero A.R., Chen L., Dashti S., Ghofrani A., Taiebat M., Arduino P., 2018. Site response in a layered liquefiable deposit: evaluation of different numerical tools and methodologies with centrifuge experimental results. Journal of Geotechnical and Geoenvironmental Engineering, Vol. 144, No. 10, ID 04018073, https://doi.org/10.1061/(ASCE)GT.1943-5606.0001947.
23. Shen Y., Zhong Z., Li L., Du X., 2022. Nonlinear solid-fluid coupled seismic response analysis of layered liquefiable deposit. Journal of Applied Sciences, Vol. 12, No. 11, ID 5628, https://doi.org/10.3390/app12115628.
24. Ter-Martirosyan A., Le D.A., 2020. Calculation of the settlement of pile foundations taking into account the influence of soil liquefaction. IOP Conference Series Materials Science and Engineering, Vol. 869, No. 5, ID 052025, https://doi.org/10.1088/1757-899X/869/5/052025.
25. Wang R., Fu P., Zhang J.M., 2016. Finite element model for piles in liquefiable ground. Computers and Geotechnics, Vol. 72, No. 5,
pp. 1–14, https://doi.org/10.1016/j.compgeo.2015.10.009.
26. Wu W., Bauer E., Kolymbas D., 1996. Hypoplastic constitutive model with critical state for granular materials. Mechanics of Materials, Vol. 23, No. 1, pp. 45–69.

OMAR AL-F.S. AL-DAMLUJI*
University of Baghdad; Baghdad, Iraq
Address: Al-Jadriya, 10071, Baghdad, Iraq
AHMED S. JAWAD
University of Baghdad; Baghdad, Iraq; a.jawad1901p@coeng.uobaghdad.edu.iq
BUSHRA S. ALBUSODA
University of Baghdad; Baghdad, Iraq; dr.bushra_albusoda@coeng.uobaghdad.edu.iq