Bored Injection Piles ERT (RIT, FORST, ERST) - Structures for Ensuring Slope Stability
Sokolov Nikolai Sergeevich1,2
1NPF LLC “FORST”, 109a, ul. Kalinina, 428000, Cheboksary, Russian Federation
2Federal State-Funded Educational Institution of Higher Education, IN Ulianov Chuvash State University, 15, Moskovskiy pr., 428015, Cheboksary, Russian Federation
NS Sokolov, Candidate of Sciences (Engineering), Associate Professor, Director, Federal State-Funded Educational Institution of Higher Education, IN Ulianov Chuvash State University, 15, Moskovskiy pr., 428015, Cheboksary, Russian Federation.
The problem of increasing the bearing capacity of foundations is always an urgent task in modern geotechnical construction. It is of particular importance when building on slopes cut by ravines. As a rule, construction on slope surfaces due to the discharge of filtration flows in the form of springs is always a problematic measure. Hydrogeological processes often bring rugged surfaces intended for the construction of objects into an unstable state, leading them to landslides. Thus, the safe erection of buildings and structures in such areas is always accompanied by the simultaneous erection of retaining buried building structures. The most competitive retaining structures are monolithic reinforced concrete corner retaining walls erected on bored piles and fixed with ground anchors. The article gives examples of the use of ERT bored piles (RIT, FORST, ERST) and ERT ground anchors.
Keywords: Retaining Recessed Structures, Geotechnical Construction, EDT Electric Discharge Technology, EDT Bored Pile, Monolithic Reinforced Concrete Grillage
Modern capital construction for the most part is confined to areas heavily crossed by ravines and slopes [1-3]. As a rule, such construction sites are characterized and classified as unstable due to the fact that filtration flows are unloaded on their inclined surfaces. When static equilibrium is disturbed, filtration processes on slopes in most geotechnical cases lead to flooding of construction pits, water saturation of engineering-geological elements that make up engineering-geological sections of the foundations of built-up objects [4-7]. In the case of a qualified approach to the engineering preparation of the construction site in such conditions, it is possible to avoid negative factors. So, for example, in modern geotechnical practice, ERT (RIT, FORST, ERST) bored injection piles are widely used as buried structures [8,9]. Their use in combination with ground anchors makes it possible to ensure the stability of slopes including corner monolithic reinforced concrete retaining walls in their joint static work [10-12]. The article under consideration presents a number of successfully completed geotechnical objects on slopes in various regions of the Middle Volga region, carried out with the direct participation of the authors of the article.
Object Number 1: Monolithic reinforced concrete corner retaining wall as a recessed retaining structure on piles of bored-injection ERT (RIT, FORST, ERST) on the slope of the Oka congress in the city of. N. Novgorod. The support was erected in connection with the expansion towards the slope of the right-side bank of the Oka River of two-way traffic into a one-way road. In connection with the placement of one strip directly on the slope, it became necessary to install four corner monolithic reinforced concrete retaining walls (see Figure 1a) on EDT bored-injection piles (Figure 1b). The architectural elegance of the retaining walls can be observed from Komsomolskaya Square. All four retaining walls at their tops pour into one inclined straight line. Reliable operation of retaining walls indicates the correct choice of technical solution.
Object Number 2: Ribbon pile field of ERT (RIT, FORST, ERST) drilled piles united by a monolithic reinforced concrete grillage as a buried retaining structure along Pozharskaya Street in Nizhny Novgorod (see Figure 2 a and 2 b). The need to erect such a building structure was caused in connection with the construction of a five-story hotel “Moscow”. It should be noted that initially there was a project for a pile field of bored piles with a diameter of d = 630.0 mm. Due to the impossibility of the tightness of the construction site, it was decided to switch to ERT bored injection piles (RIT, FORST, ERST). The hotel was commissioned more than five years ago and no one has any questions about the reliable operation of the retaining wall.
Object number 3: Recessed retaining reinforced concrete structures using ERT bored piles (RIT, FORST, ERST), ERT ground anchors and monolithic reinforced concrete corner retaining walls in the city of Cheboksary (see Figure 3). The need to design and install monolithic reinforced concrete corner retaining walls together with ERT bored piles (RIT, FORST, ERST) and ERT ground anchors arose in connection with horizontal movements of the leaning slope and deformations of the objects erected on it. Initially, the project of retaining structures of bored piles with a diameter of d = 630.0 mm was carried out in one row with the installation of a monolithic reinforced concrete strapping belt. When analyzing the causes of deformations, several flaws were revealed. Firstly, a single-row pile arrangement was used as buried structures, which is not acceptable from the point of view of maintaining the rigidity of the structure. Secondly, it is arranged only at the base of the slope. It was necessary to arrange the retaining building structures on the top of the slope. Thus, the use of ERT borehole piles (RIT, FORST, ERST) and ERT ground anchors in combination with monolithic reinforced concrete corner retaining walls at the site made it possible to ensure trouble-free operation of the leaning slope.
- Ilyichev VA, Mangushev RA, Nikiforova NS (2012) Experience in the development of the underground space of Russian megacities. Foundations, foundations and soil mechanics. 2: 17-20.
- Hassiotis S, Chamcau JL, Gunaratne M (1997) Design method for stabilisation of slopes with piles. Journal of Geotechnical and Geoenvironmental Engineering 123: 314-323.
- Lee JH, Salgado R (1999) Detervination of pile base resistance in sands. Journal of Geotechnical and Geoenvironmental Engineering 125: 673-683.
- Mandolini A, Russo G, Veggiani C (2005) Pile foundations: experimtntal investigations, analisis and design. Ground Engineering 38: 34-38.
- Nikiforova NS (2011) Geotechnical cut-off diaphragms for built-up area protection in urban underground development Nikiforova NS Vnukov. The pros, of the 7thI nt. Symp. Geotechnical aspects of underground construction in soft ground, 16-18 May, 2011, tc28 IS Roma, AGI, 2011, No157NIK.
- Petrukhin OA, Shuljatjev OA, Mozgacheva (2003) Effect of geotechnical work on settlement of surrounding buildings at underground construction. Proceedings of the 13th European Conference on Soil Mechanics and Geotechnical Engineering. Prague.
- Th Triantafyllidis, R Schafer (2007) Impact of diaphragm wall construction on the stress state in soft ground and serviceability of adjacent foundations. Proceedings of the 14th European Conference on Soil Mechanics and Geotechnical Engineering, Madrid, Spain, 22 27 September 2007. 683-688.
- Sokolov NS (2016) Technological methods for the installation of bored injection piles with multi-place broadening. Housing construction. 10: 54.
- Sokolov NS, Sokolov SN, Sokolov AN (2023) Inconsistencies in the reliable operation of the cultural heritage object - the Chuvash Drama Theater named after Ivanova KV. Housing construction. 4: 70-75.
- Sokolov HC, Petrov MV, Ivanov VA (2014) Problems of calculation of bored-injection piles made using discharge-pulse technology. In the collection: New in architecture, design of building structures and reconstruction. Materials of the VIII All-Russian (II International) Conference. Editorial Board: Sokolov NS (responsible editor), D.L. Kuzmin (responsible secretary), Plotnikov AN, Sakmarova LA, Lukin AG, Bogdanov VF, Tarasov VI. 415-420.
- Sokolov NS, Sokolov AN, Sokolov SN, Glushkov VE, Glushkov AV (2017) Calculation of ERT bored injection piles of increased bearing capacity // Housing construction 11: 20-25.
- Sokolov NS, Sokolov SN, Sokolov AN (2016) Experience in restoring the building of the Vvedensky Cathedral in the city of Cheboksary. Geotechnics 1: 60-65.