Tag Archives: несущая способность
Analysis of the influence of fire-retardant coating on strenth properties of wooden building constructions
Russian and international experience in operation of buildings and facilities of different functional purpose, as well as the results of safety research show that operating companies, maintenance staff and supervisors should make ensuring the observance of fire safety requirements at construction sites a priority. The current fire codes classify building materials only in terms of fire hazard, so most of the modern fire-resistant materials for wooden building constructions are designed for reduction of fire hazard by limiting flame spread in case of fire. However, one of the criteria for fire-engineering classification of building constructions is their fire resistance degree. At the same time, the existing fire safety codes and standards apply this parameter for characterizing metal and reinforced concrete constructions only, which significantly limits the use of wooden constructions as load bearing ones. Therefore, it is appropriate to develop a flame retardant, which helps to raise the fire resistance of wooden building constructions in case of fire. Based on the analysis of the existing tools and methods for fire protection of wooden building construction elements, the authors chose the optimal ratio of intumescent coating components for wooden construction structures, application of which in conditions of a construction site is the most promising and effective method of wood material fire protection. The article considers the impact of the fire-retardant coating developed on strength properties of wooden building constructions. The results and methods of the tests conducted for determination of tensile strength of wooden structures after fire exposure are given. The developed fire-retarding composition of the paint helps to prevent decrease of tensile strength of wooden structures in case of fire, and, therefore, to keep their load bearing capacity. These results were achieved due to formation of porous coke framework at high temperatures on the surface of fireproofed samples, which helps to improve thermal-physical properties of the coating as a heat insulating material and increases dehydration period of the components in fire retardant paint and in the wood itself. The developed fire-retarding composition of the paint is harmful for execution of work on fire protection of wood structures of buildings and facilities of civil and industrial construction of the Republic of Bashkortostan.
Problem of building and designing on semi rocky soils (lower Permian soils) is problematic for many regions. In particular, in Russia the problems of building on semirocky soils are not given clearly enough in national construction norms and standards. Approximate calculation methods of end-bearing pile point resistance on weak fissured semi rocky soils, based on SP 24.13330.2011 "Pile foundations" are presented. Some results of static load test are confirms the approximate calculation method results. This method is recommended to use in engineering practice.
The estimation of durability and safety of operation of the welded technological pipeline from a steel 17G1SU in diameter 400 mm with thickness of a wall of 10 mm, loaded with internal pressure 6 МPа, intended for transportation of oil products is made. Dependence of change of limiting bearing ability of the pipeline on operation time in an excited environment is established. Calculation of pressure in a real design with the revealed not through defects is essentially specified. The expediency of application of diagrams of an indestructibility is proved at an estimation of resource characteristics and survivability of the welded equipment from low-alloy steels.
Development of stocks of hydrocarbon raw material and investigation of their site today moves ahead more and more on northern territories of Russia, where there is no developed high system. The technics of oil-and-gas branch and transport on its delivery becomes more powerful, increasing in weight. At the time global changes in a climate remove in later terms of becoming of safe carrying ability of ice ferries and marshy roads. All this dictates development of the ways reinforcement of carrying ability of ice ferries and marshland.