Research paper "The use of modern materials for filling the inner cavity of piles and the use of seam pipes as pile structures" | The team of authors of PJSC NK Rosneft and the N. M. Gersevanov Research Institute of Natural Sciences
Due to the presence of permafrost soils, the climate change observed in the world in recent years is of particular importance both for the cryolithozone and for the Russian Arctic as a whole. An increase in air temperature causes their degradation and intensification of dangerous cryogenic processes that negatively affect the stability of buildings and structures. As the temperature of permafrost increases, their strength properties decrease and their deformation characteristics increase, which subsequently leads to the destruction of capital construction facilities.
Joint research work on changing the regulatory impact of the Codes of Practice SP 25.13330 "Foundations and foundations on permafrost soils" and SP 24.13330 "Pile foundations" has brought positive results.
Laboratory studies were conducted in the laboratories of the N.M. Gersevanov National Research Institute of Physics and Technology, and field tests of piles were conducted in Irkutsk region.
As part of the work, it was possible to confirm (an expert opinion was developed) the possibility of using a dry cement-sand mixture (hereinafter referred to as CPS) when filling the cavities of steel piles in thawed and frozen soils, while ensuring their tightness and seam pipes as an alternative to seamless ones for structures of normal and increased responsibility.
The amendments made to the text of SP 25.13330 are designed to close existing gaps in the implementation of oil and gas facilities in harsh climatic conditions, and will also avoid the need to develop special technical conditions for deviation from the requirements of regulatory and technical documentation.
Potential effect after the entry into force of the revised Joint venture 25.13330:
- more than 365 thousand rubles. per year
- year-round management of the CMP
- the absence of wet processes when conducting SMR in harsh climatic conditions
- reducing the timing of the QMS
- lack of annual investments in the development of STU
The changes made to the text of the code of rules "Foundations and foundations on permafrost soils" are designed to close existing gaps in design requirements and will allow in the future to avoid the need to develop a number of special technical conditions related to the possibility of using straight-seam pipes for piling in permafrost soils, the use of dry mixes for filling metal piles. The results of the work were agreed upon and highly appreciated by the organizations of the oil and gas industries. The changes will make it possible to achieve significant cost savings during construction in the Far North, including due to the absence of a long shoulder for the delivery of concrete mortar and the need to organize mortar units on the site. These savings are estimated at over 400 million rubles per year, and the use of CPS will reduce the installation time of work by approximately 20% relative to the existing labor costs when using solutions."
