Âñåðîññèéñêèé íàó÷íî-èññëåäîâàòåëüñêèé èíñòèòóò ïðîòèâîïîaeàðíîé îáîðîíû Ì×Ñ Ðîññèè (Ðîññèÿ, 143903, ã. Áàëàøèõà Ìîñêîâñêîé îáë., ìêð. ÂÍÈÈÏÎ, 12) ÐÅÇÞÌÅ Ââåäåíèå. AEåëåçîáåòîííûå êîíñòðóêöèè èç òÿaeåëîãî áåòîíà ïîâûøåííîé âëàaeíîñòè (áîëåå 3,5 %) èìåþò ñêëîííîñòü ê âçðûâîîáðàçíîìó ðàçðóøåíèþ, êîòîðîå ìîaeåò ïðèâåñòè ê ïðåaeäåâðåìåííîìó íàñòóïëåíèþ ïðåäåëà îãíåñòîéêîñòè òàêèõ êîíñòðóêöèé è ÷àñòè÷íîìó èëè ïîëíîìó îáðóøåíèþ çäàíèé è ñîîðóaeåíèé. Ïîâûøåííàÿ âëàaeíîñòü aeåëåçîáåòîííûõ êîíñòðóêöèé îáû÷íî âñòðå÷àåòñÿ â ïîäçåìíûõ ñîîðóaeåíèÿõ è âî âíîâü âîçâîäèìûõ çäàíèÿõ. Îãíåñòîéêîñòü aeåëåçîáåòîííûõ òþáèíãîâ ïîäçåìíûõ ñîîðóaeåíèé â çíà÷èòåëüíîé ñòåïåíè çàâèñèò îò âçðûâîîáðàçíîãî (õðóïêîãî) ðàçðóøåíèÿ áåòîíà ïðè âîçäåéñòâèè âûñîêèõ òåìïåðàòóð ïîaeàðà íà ïîâåðõíîñòü îáäåëêè òîííåëÿ. Ìàòåðèàëû è ìåòîäû.  êà÷åñòâå îáúåêòà èññëåäîâàíèÿ áûëè âûáðàíû aeåëåçîáåòîííûå òþáèíãè èç òÿaeåëîãî áåòîíà âëàaeíîñòüþ 6 % ñ äîáàâêîé ïîëèïðîïèëåíîâîé ôèáðû â êîëè÷åñòâå 1 êã/ì 3 . Ïðîâåäåíû êðóïíîìàñøòàáíûå îãíåâûå èñïûòàíèÿ íà ñïåöèàëüíî èçãîòîâëåííîì ñòåíäå ïðè íàãðóaeåíèè îáðàçöîâ âåðòèêàëüíîé è ãîðèçîíòàëüíîé íàãðóçêîé. Ðåçóëüòàòû è îáñóaeäåíèå. Ïðåäñòàâëåíû îñíîâíûå ðåçóëüòàòû ýêñïåðèìåíòàëüíîãî èññëåäîâàíèÿ îãíåñòîéêîñòè aeåëåçîáåòîííûõ òþáèíãîâ ñ äîáàâêîé ïîëèïðîïèëåíîâîé ôèáðû è áåç íåå. Ïî ðåçóëüòàòàì óñòàíîâëåíî, ÷òî ïðåäåë îãíåñòîéêîñòè aeåëåçîáåòîííîãî òþáèíãà ñ äîáàâêîé ïîëèïðîïèëåíîâîé ôèáðû ñîãëàñíî ÃÎÑÒ 30247.0-94 ñîñòàâèë íå ìåíåå 125 ìèí (REI 120). Ðàçðàáîòàíà àíàëèòè÷åñêàÿ ìîäåëü îöåíêè îãíåñòîéêîñòè. Äëÿ ðåøåíèÿ òåïëîòåõíè÷åñêîé çàäà÷è ïðîâåäåí ÷èñëåííûé ýêñïåðèìåíò ñ ïîìîùüþ ïðîãðàììíîãî êîìïëåêñà "ANSYS". Ïðåäëîaeåíà àíàëèòè÷åñêàÿ çàâèñèìîñòü îïðåäåëåíèÿ äîïîëíèòåëüíîãî òåìïåðàòóðíîãî ïðîãèáà äëÿ ãåîìåòðè÷åñêè íåëèíåéíîãî ýëåìåíòà. Ðàñ÷åò ïðåäåëà îãíåñòîéêîñòè aeåëåçîáåòîííîãî òþáèíãà ñ äîáàâêîé ïîëèïðîïèëåíîâîé ôèáðû ïî ðàçðàáîòàííîé àíàëèòè÷åñêîé ìîäåëè ñ ó÷åòîì ðàíåå ïîëó÷åííûõ ïðî÷íîñòíûõ è òåïëîòåõíè÷åñêèõ õàðàêòåðèñòèê ïîäòâåðäèë ðåçóëüòàòû îãíåâûõ èñïûòàíèé: ïðåäåë îãíåñòîéêîñòè ñîñòàâèë REI 120. Çàêëþ÷åíèå. Èñïîëüçîâàíèå äëÿ îãðàaeäàþùèõ êîíñòðóêöèé òîííåëÿ aeåëåçîáåòîííûõ òþáèíãîâ èç ôèáðîáåòîíà ñ ïîëèïðîïèëåíîâîé ôèáðîé ïîçâîëèò çíà÷èòåëüíî ñíèçèòü çàòðàòû íà óñòðîéñòâî îãíåçàùèòû è ñîêðàòèòü ñðîêè ñòðîèòåëüñòâà.Êëþ÷åâûå ñëîâà: ñòàíäàðòíûé òåìïåðàòóðíûé ðåaeèì ïîaeàðà; òåïëîòåõíè÷åñêàÿ çàäà÷à; ñòàòè÷åñêàÿ (ïðî÷íîñòíàÿ) çàäà÷à; âçðûâîîáðàçíîå (õðóïêîå) ðàçðóøåíèå áåòîíà; îáäåëêà òîííåëÿ.

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The article presents the results of studies on parametric approximation in spaces R2 (functions of one variable), R3 (functions of two variables) and Rn(n>3) (functions of three or more variables). Various classes of functions satisfying a priori conditions were studied: f(0, 0, 0)=0, $\mathop {\lim 1}\limits_{{x_i} \to + \infty } \,\,({x_1},\, \ldots ,\,{x_n}) = {c_i}$, ci = cont. Working algorithms and C/C++ software functioning in Microsoft Visual Studio 2019 system in Microsoft Windows 10 environment were developed. The main studies of the authors were aimed at developing effective computational algorithms for constructing approximating functions of two variables from various given classes of three-dimensional data samples (three-dimensional interconnected time series). The article provides a detailed description of the problem statement, introduces classes of approximating functions, provides algorithms for estimating the parameters of approximating functions and a description of the software. The estimation algorithm considered in the article is constructed according to the scheme of the coordinate descent method with optimization of the step length (Gauss-Seidel method).

Hay is one of the most valuable types of roughage in the diet of ruminants. During the winter period, animals get about half of the nutrients and digestible protein from hay. Leguminous-cereal hay is rich in protein, minerals, carbohydrates, vitamins. When harvesting hay in rolls, balers with a constant-volume pressure chamber are most often used. The roll forming process consists in continuously winding the flow of plant mass onto the core to a predetermined diameter. The process of roll formation occurs due to the gradual compaction of the roll from the outside, as a result of which rolls with a low density core are formed. Studies have shown that hay compaction from the outside leads to the fact that pressure transfer from the outer layers to the inner layers occurs with some delay (stress relaxation) and the location of stems in this case will have some significant effect on the density of hay inside the roll. Experimental studies have shown that the density of hay inside the roll also varies as for the width of the roll. In the middle part of the roll (in width), the density of hay is 2 to 3 times higher than along its edges, the zone of increased density is 0.7 m, which is 44 % of the width of the roll.