مهندسی سازه و ساخت

مهندسی سازه و ساخت

بازتوزیع بار و پاسخ سازه ای قابهای بتن آرمه شهری تحت تاثیر نشست سطحی ناشی از حفاری تونل

نوع مقاله : علمی - پژوهشی

نویسندگان
1 کارشناس ارشد، دانشکده مهندسی، دانشگاه کاشان، کاشان، ایران
2 استادیار، دانشکده مهندسی، دانشگاه کاشان، کاشان، ایران
10.22065/jsce.2025.509143.3672
چکیده
حفاری زیرزمینی و ایجاد تونل در مناطق شهری پرجمعیت می‌تواند باعث بروز نشست غیریکنواخت در سطح زمین و در نتیجه ایجاد خسارت‌های قابل توجه در سازه‌های موجود شود. ارزیابی و شناسایی الگوی بازتوزیع نیروهای داخلی در اجزای باربر ساختمان‌‌های متداول شهری، از جمله اقداماتی است که برای مقابله با این آسیب‌ها ضرورت دارد. در این پژوهش، پاسخ یک ساختمان مسکونی ۵ طبقه تیپ با سیستم قاب خمشی بتنی تحث اثر ۱۲ سناریوی مختلف ارزیابی و مقایسه گردید. این سناریوها با فرض دو پروفیل نشست ناشی از عبور تونل (با بیشینه نشست سطحی ۹۰ یا ۲۳۰ میلیمتر)، 3 محل عبور محور تونل از زیر پلان ساختمان (گذرنده از زیر قاب میانی، عبور از زیر قاب ما قبل آخر و یا گذرنده از کنار پلان) و دو زاویه بین محور تونل و محورهای اصلی سازه (۰ یا 45 درجه) تعریف گردیدند. در ادامه، با اعمال گام به گام نشست تفاضلی فزاینده در پای ستون‌ها، روند تغییرات نیروی محوری ستون‌های طبقه اول و الگوی ایجاد و انتشار مفاصل پلاستیک در سازه مورد بررسی قرار گرفت. بر پایه یافته‌های مدل‌های عددی، اگرچه پروفیل با بیشینه نشست بزرگتر، تغییرات گسترده‌تری در نیروی محوری ستون‌ها ایجاد نمود ولی موقعیت قرارگیری پلان سازه نسبت به پروفیل نشست نیز اثرات چشمگیری در بازتوزیع نیروهای داخلی برجا گذاشت. در کلیه سناریوها، ستون‌های دارای بزرگترین نشست، همواره با افت شدیدی در مقدار نیروی محوری فشاری خود مواجه گردیدند. ضمنا مفاصل خمیری در وهله نخست عموما در انتهای تیرهای پل‌زننده بر روی دو ستون مجاوری که دارای بیشترین نشست تفاضلی بودند تشکیل شده و تعداد آنها در حالت عبور تونل از زیر قاب میانی سازه و به موازات آن، به بیشترین مقدار خود رسید.
کلیدواژه‌ها

موضوعات


عنوان مقاله English

Load redistribution and structural response of urban Reinforced Concrete frames subjected to tunnel-induced Surface settlements

نویسندگان English

Mojtaba Masaeimanesh 1
Alireza Pachenari 2
1 M.Sc., Faculty of Engineering, University of Kashan, Kashan, Iran
2 Assistant professor, Faculty of Engineering, University of Kashan, Kashan, Iran
چکیده English

Underground excavation and tunnel construction in densely populated urban areas can lead to uneven surface settlements, which may cause substantial damage to existing structures. To mitigate such risks, it is essential to evaluate the load redistribution patterns in the load-bearing elements of typical residential buildings. In this study, the response of a 5-story reinforced concrete moment frame residential building was assessed and compared under 12 different scenarios. The scenarios considered two settlement profiles with maximum surface settlements of 90 mm and 230 mm, three building positions relative to the settlement profile, and two angles between the tunnel axis and the main axes of the structure (0 and 45 degrees). By incrementally applying differential settlement to the columns, changes in the axial force of the first-story columns and the formation patterns of plastic hinges were investigated. According to the numerical model findings, although the settlement profile with the maximum surface settlement induced more significant variations in the axial forces of the columns, but the location of the frame relative to the settlement profile also had significant effects on the redistribution of internal forces. In all scenarios, the columns subjected to the largest settlement experienced a severe reduction in their compressive axial force. Furthermore, plastic hinges initially formed predominantly at the ends of the beams connecting the two adjacent columns with the largest differential settlement. The number of plastic hinges reached its peak when the tunnel passed beneath the central frame of the structure and aligned parallel to it.

کلیدواژه‌ها English

Surface settlement profile
Concrete moment frame
Tunnel excavation
Load redistribution
Differential settlement
Plastic hinge
[1] Sasani, M., Bazan, M., & Sagiroglu, S. (2007). Experimental and analytical progressive collapse evaluation of actual reinforced concrete structure. ACI Structural Journal, 104(6), 731.
[2] Qian, K., Li, B., & Ma, J. X. (2015). Load-carrying mechanism to resist progressive collapse of RC buildings. Journal of Structural Engineering, 141(2), 04014107.
[3] Hou, J., & Song, L. (2016). Progressive collapse resistance of RC frames under a side column removal scenario: The mechanism explained. International Journal of Concrete Structures and Materials, 10, 237-247.
[4] Arezoomand, M., Pachenari, A. (2021). Load redistribution pattern in a RC moment frame due to excavation-induced 3D ground surface settlement profiles. Journal of Structural and Construction Engineering, 8(10), 5-22.
[5] Lin, L., Hanna, A., Sinha, A., and Tirca, L. (2015). Structural response to differential settlements of its foundations, Journal of Civil Engineering Reserach, 5(3): 55-69.
[6] Hakam, A., Ismail, F. A., Al Jauhari, Z., & Chairani, C. (2024). Evaluation of an RC frame building exposed to differential settlement in Padang city, Indonesia. GEOMATE Journal, 27(123), 125-132.
[7] Chen, W., & Hanna, A. (2023). Experimental investigation on structural response of multi-story buildings subjected to differential settlement of its foundations. International Journal of Structural Integrity, 14(2), 204-228.
[8] Fayed, S., Mansour, W., & Farhan, M. H. (2022). Using surveying instruments in monitoring 3D deformations of RC structure subjected to differential settlement of its footings. Arabian Journal for Science and Engineering, 47(4), 5315-5336.
[9] Lin, L., Hanna, A., Sinha, A., & Tirca, L. (2017). High-rise building subjected to excessive settlement of its foundation: a case study. International Journal of Structural Integrity, 8(2), 210-221.
[10] El Naggar, A., Youssef, M. A., El Naggar, H., & El Ansary, A. M. (2021, May). Differential settlement effect on RC framed structures. In: Canadian Society of Civil Engineering Annual Conference. Singapore: Springer Nature Singapore, 683-694.
[11] Pachenari, A., Pirayande, E., Pachenari, Z. (2019). Influence of increasing differential settlement under columns on a RC frame response considering different support conditions. Journal of Structural and Construction Engineering, 6(Special Issue 1), 173-186.
[12] Camós, C., Molins, C., & Arnau, O. (2014). Case study of damage on masonry buildings produced by tunneling induced settlements. International Journal of Architectural Heritage, 8(4), 602-625.
[13] Houlsby, G. T., Burd, H. J., & Augarde, C. E. (1999). Analysis of tunnel-induced settlement damage to surface structures. In: Proceedings of the 12th European Conference on Soil Mechanics and Foundation Engineering. Delft: The Netherlands Society of Soil Mechanics and Geotechnical Engineering, 147-152.
[14] Castaldo, P., & De Iuliis, M. (2014). Effects of deep excavation on seismic vulnerability of existing reinforced concrete framed structures. Soil Dynamics and Earthquake Engineering, 64, 102-112.
[15] Boldini, D., Losacco, N., Bertolin, S., & Amorosi, A. (2018). Finite element modelling of tunnelling-induced displacements on framed structures. Tunnelling and Underground Space Technology, 80, 222-231.
[16] Yang, H., Shi, H., Jiang, X., Liu, C., & Yu, L. (2021). Study on Influence of Construction Process of Double-Line Shield Tunnels on Frame Structure. Geotechnical and Geological Engineering, 39(2), 1465-1484.
[17] National Building Regulations (2020). Design and Implement of Reinforced Concrete Buildings. Tehran: Ministry of Rood & Urban Development (in Persian).
[18] National Building Regulations (2020). Loads on buildings. Tehran: Ministry of Rood & Urban Development (in Persian). [19] Building and Housing Research Center (2014). Iranian Code of Practice for Seismic Resistant Design of Buildings. Standard No. 2800, 4th edition. Tehran: BHRC.
[20] Peck, B. B. (1969). Deep excavation and tunnelling in soft ground, State of the art volume. In: 7th International Conference on Soil Mechanics and Foundation Engineering. Mexico City, Sociedad Mexicana de Mecanica, 225-290.
[21] Son, M., & Cording, E. J. (2011). Responses of buildings with different structural types to excavation-induced ground settlements. Journal of Geotechnical and Geoenvironmental Engineering, 137(4), 323-333.
[22] Hasanpour, R., Chakeri, H., Ozcelik, Y., & Denek, H. (2012). Evaluation of surface settlements in the Istanbul metro in terms of analytical, numerical and direct measurements. Bulletin of Engineering Geology and the Environment, 71, 499-510.
[23] JAME BEHRO CONSULTING ENGINEERS Co (2025). Weekly report of Tehran Metro Line 10 instrumentation- Issue 9: First week of Bahman 1403. Tehran.  Tehran Urban & Suburban Railway Operation Co, 1-18.
[24] Darabi, A., Ahangari, K., Noorzad, A., & Arab, A. (2012). Subsidence estimation utilizing various approaches–A case study: Tehran No. 3 subway line. Tunnelling and Underground Space Technology, 31, 117-127.
[25] Ocak, I. (2008). Control of surface settlements with umbrella arch method in second stage excavations of Istanbul Metro. Tunnelling and Underground Space Technology, 23(6), 674-681.
[26] Yi, W. J., He, Q. F., Xiao, Y., & Kunnath, S. K. (2008). Experimental study on progressive collapse-resistant behavior of reinforced concrete frame structures. ACI Structural Journal, 105(4), 433-439.
[27] SAP2000®, Version 19.2.2 “Linear and Nonlinear Static and Dynamic Analysis and Design of Three-Dimensional
Structures,” Computers and Structures Inc., Berkeley, CA, 2017.
[28] FEMA 356, F. E. (2000). Prestandard and commentary for the seismic rehabilitation of buildings. Federal Emergency Management Agency: Washington, DC, USA.
[29] National Building Regulations (2021). Geotechnics and foundation engineering. Tehran: Ministry of Rood & Urban Development (in Persian).

  • تاریخ دریافت 09 اسفند 1403
  • تاریخ بازنگری 05 اردیبهشت 1404
  • تاریخ پذیرش 18 اردیبهشت 1404