Study of Structures Stress-Strain State of a Building with Protective Measures in the Zone of Deep Excavation Impact

In conditions of underground construction in dense urban development, including the construction of deep pits, it is necessary to ensure the strength, reliability and durability of existing structures. This is facilitated by the implementation of a geotechnical forecast using the «base-foundations-aboveground structures» system in relation to the surrounding development. The results of the study of the stress-strain state of structures when calculating the surrounding development using such a system in the zone of influence of a deep pit are presented, including the construction of protective measures (strengthening of foundations with bored-injection piles, fixing their base with soil-cement elements, the arrangement of a geotechnical cut-off screen, underpinning of the slab foundation). For two types of ground conditions (Sands from shallow to gravelly, medium density and dense; loams and clays from soft-plastic to fluid), numerical experiments were performed in the Plaxis 2D program on a geotechnical model consisting of a deep pit, an array of soil and a building of the surrounding construction site. The features of setting the Plaxis 2D load from a building in this case are considered. The analysis of the received displacements and additional forces in the building structures of the surrounding development is made. With the help of numerical studies, it was possible to determine which of the considered protective measures made it possible to the most effectively reduce additional efforts in the building structures.

A.V. KONNOV, Engineer, (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Research Institute of Building Physics of RAACS (21, Lokomotivniy Driveway, Moscow, 127238, Russian Federation)

1. Shashkin A.G., Shashkin K.G. The main regularities of interaction between the base and above-ground structures of the building. Razvitie gorodov i geotekhnicheskoe stroitel’stvo. 2006. No. 10, pp.63–92.
2. Ulitskii V.M., Shashkin A.G., Shashkin K.G., Shashkin V.A. Osnovy sovmestnykh raschetov zdanii i osnovanii [Basic principles of buildings and bases design]. Saint Petersburg: Georeconstructcia, 2014. 328 p.
3. Ter-Martirosyan Z.G., Ter-Martirosyan A.Z., Several problems of underground construction. Zhilishchnoe Stroitel’stvo [Housing Constructions]. 2013. No. 9, pp. 2–6. (In Russian).
4. Shashkin A.G., Shashkin K.G. Interaction of buildings and bases: calculation methods and their application in design. Razvitie gorodov i geotekhnicheskoe stroitel’stvo. 2003. No. 7, pp.129-145. (In Russian).
5. Ilyichev V.A., Nikiforova N.S., Tupikov M.M. Deformation of soil masses during construction of shallow utility tunnels. Osnovaniya, fundamenty i mekhanika gruntov. 2011. No. 3, pp. 8–15. (In Russian).
6. Nikiforova N.S. Obespechenie sokhrannosti zdanii v zone vliyaniya podzemnogo stroitel’stva [Ensuring of buldings’ preservation in the zone of underground construction impact]. Moscow: MGSU, 2016. 152 p.
7. Ter-Martirosyan A.Z., Sidorov V.V., Ermoshina L.Yu. Peculiarities of using the results of laboratory tests for geotechnical calculations. Geotekhnika. 2018. Vol. 10. Iss. 1–2, pp. 28–38. (In Russian).
8. Bathe K.J. Finite Element Procedures. New Jersey.: Prentice Hall, 1996. 1037 p.
9. Nikiforova N.S., Konnov A.V. The forecast of buildings` settlement with protection measures in the zone of underground construction influence. Vestnik grazhdanskikh inzhenerov. 2016. No. 2 (55), pp. 94–100. (In Russian).
10. Nikiforova N.S., Konnov A.V., Zakirova A.I. A study of the effectiveness of protective measures for existing buildings with underground construction subject to the production technology works. Soil mechanics in geotechnics and foundation construction: proc. of int. sci. tech. conf. Novocherkassk. 2018. pp. 430–440. (In Russian).
11. Ilyichev V.A., Nikiforova N.S., Konnov A.V. A settlement calculation for neighbouring buildings with mitigation measures upon underground construction. Proceedings of 19th International Conference on Soil Mechanics and Geotechnical Engineering. Seul, Korea. 2017, pp. 1789–1792.
12. Nadezhda Nikiforova, Artem Konnov. Settlement prediction for protected buildings nearby deep excavation. IOP Conf. Ser.: Mater. Sci. Eng. 2018. No. 365. http://iopscience.iop.org/article/10.1088/1757-899X/365/4/042028/pdf (дата обращения 18.11.2019).
13. Mangushev R.A., Nikiforova N.S. Tekhnologicheskie osadki v zone vliyaniya podzemnogo stroitel’stva [Technological settlements in the zone of underground construction impact]. Мoscow: ASV, 2017. 168 p.