INVESTIGATION OF THE WORK OF DRILL-IMPACT REINFORCED CONCRETE MICROPILES WITH ENLARGED TOE OF DIFFERENT DIAMETERS

Visnyk LNAU: Architecture and Farm Building 2019 №20: 50-52

INVESTIGATION OF THE WORK OF DRILL-IMPACT REINFORCED CONCRETE MICROPILES WITH ENLARGED TOE OF DIFFERENT DIAMETERS

Hnatiuk O., Candidate of Engineering Science
Kosarchyn V., Physics and Mathematics Ph.D.
Lapchuk M. Senior teacher
Lviv National Agrarian University

https://doi.org/10.31734/architecture2019.20.050

Annotation

The research determines impact of the enlargement diameter on the bearing capacity drill-impact reinforced concrete micropiles by means of theoretical studies and experiments.

In order to study impact of the diameter of a pile and enlarged toe on the bearing capacity of drill-impact reinforced concrete micropiles with enlarged toe, two full-scale experimental samples MP-1 with diameter of 250 mm and a spread of 400 mm and MP-2 with a diameter of 200 mm and spread of 350 mm length of 3m in both cases were made in the construction laboratory of LNAU. Plastic sandy loam soils was used as a basis for the piles.

Field researches of the experimental samples of micropiles were carried out according to the method of DSTU B V.2.1-27: 2010, and the theoretical calculation of their bearing capacity was carried out in accordance with the methodology of the current norms of DBN B.2.1-10-2009.

As a result of the research, it was found that the experimental carrying capacity was 150 kN for MP-1 and 105 kN for MP-2 (which 1.2 times exceeded the MP-1 relating to MP-2), the theoretical - 103 and 86 kN respectively (1.43 times excess). Experimental values of the bearing capacity 1.46 times exceeded the theoretically defined one for MP-1 and 1.22 for MP-2, which supplied the design of more economical foundations.

According to the obtained data, the foundations of the cottage building, using the micropiles MP-1 and MP-2, were designed, and their technical and economic comparison was made. According to the estimation, cost of one linear meter of the foundation accounted for 9505 UAH in the first case and 9692 UAH in the second. Consequently, according to the conducted experiment, use of a larger diameter (MP-1) micropiles saved only 2% of costs, despite of their better bearing capacity.

Key words

drill-impact reinforced concrete micropiles, diameter of enlarged toe, bearing capacity, geotechnical conditions, theoretical calculations, experimental researches, technical and economic comparison, estimated cost

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Link

  1. DBN В.2.1-10-2009 «Bases and foundations of constructions. Basic design provisions» with a change of 1.2. Кyiv: Minregionbud of Ukraine, 2009. 96 p.
  2. DSTU B V.2.1-27: 2010 Piles. Determination of bearing capacity, based on the results of field trials / State Committee of Ukraine for Urban Development and Architecture. Kyiv: Ukrahrbudinform, 2011. 14 p.
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  5. Hnatiuk O., Lapchuk M., Kholod P. Bearing capacity of the drill-impact micropiles with enlarged toe in the soils of different type. Journal of Lviv National Agrarian University: Architecture and Agricultural Construction. 2014. № 15. P. 45-49
  6. PP BKF Osnova. URL: http://pposnova.lviv.ua/buronabuvni.html. (accessed 27.06.2019).
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