Experimental and theoretical studies of bearing capacity and deformation of reinforced soil foundations under cyclic loading

Author(s):  
Ilizar Mirsayapov ◽  
Irina Koroleva
2018 ◽  
Vol 5 (3) ◽  
Author(s):  
Mikhail Fedotov ◽  
Maxim Loskutov ◽  
Ivan Shelemba ◽  
Alexey Kolesnikov ◽  
Igor Ovchinnikov

This article describes results of studies on the monitoring of deformations of load-bearing metal structures of a span structure of a bridge using fiber-optic sensors based on fiber Bragg gratings before and after reinforcement by polymer composite materials. It is received, that as a result of strengthening the deflection of the bridge has decreased in 2 times. The results of the experimental studies were compared with the computational justification carried out in PC LIRA 10.8. As a result of experimental and theoretical studies it was confirmed that the installed reinforcement system using composite spigots can be effectively used to restore the bearing capacity of artificial structures.


2020 ◽  
Author(s):  
Thomas Louis-Goff ◽  
Huu Vinh Trinh ◽  
Eileen Chen ◽  
Arnold L. Rheingold ◽  
Christian Ehm ◽  
...  

A new, efficient, catalytic difluorocarbenation of olefins to give 1,1-difluorocyclopropanes is presented. The catalyst, an organobismuth complex, uses TMSCF<sub>3</sub> as a stoichiometric difluorocarbene source. We demonstrate both the viability and robustness of this reaction over a wide range of alkenes and alkynes, including electron-poor alkenes, to generate the corresponding 1,1-difluorocyclopropanes and 1,1-difluorocyclopropenes. Ease of catalyst recovery from the reaction mixture is another attractive feature of this method. In depth experimental and theoretical studies showed that the key difluorocarbene-generating step proceeds through a bismuth non-redox synchronous mechanism generating a highly reactive free CF<sub>2</sub> in an endergonic pre-equilibrium. It is the reversibility when generating the difluorocarbene that accounts for the high selectivity, while minimizing CF<sub>2</sub>-recombination side-reactions.


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