Analysis of international experience in the field of building information modelling of transport infrastructure objects

In this paper, the authors consider the current state and level of implementation of building information modeling applied to transport infrastructure at the stages of their life cycle in Russia and abroad. Possible prerequisites for the transfer of knowledge and technologies of building information modeling from the civil and industrial facilities to the field of transport construction are highlighted according to the accumulated experience in the design, construction and operation of such facilities in various countries and Russia. Special emphasis is placed on examples of the world’s largest implemented or ongoing projects for the construction of transport infrastructure. The experience of implementing these projects was analyzed from the point of view of the software used in relation to all stages of the life cycle of transport infrastructure objects: design, construction and subsequent operation. The prospects for the development of data exchange formats in the context of the existing problem of mutual integration of BIM and GIS for transport infrastructure objects to ensure their complementarity and compatibility are also considered. The functional levels of the use of various software within the framework of companies implementing project activities using information modeling technologies are highlighted. A list of criteria characterizing the level of information modeling technologies integration to transport infrastructure objects into the activities of participants in the life cycle of these objects is highlighted. A review of the regulatory framework of information modeling in construction in Russia is carried out, and the main differences in this area with the regulatory regulation of this area in the European Union are noted. Conclusions are made about the key reference points for the development of information modeling of transport infrastructure facilities on a national scale, leading customer companies and contractors

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements