№ 10 (91)
октябрь, 2021 г.
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include: topographic, engineering-geological, hydro-
graphic, seismic and a number of others.
Natural conditions create obstacles for laying the
route in the shortest direction between the support
points. These obstacles can be divided into two types:
high-altitude and contour, or situational. High-altitude
obstacles are mountain ranges and gorges, high water-
sheds and deep valleys, steep steep banks of rivers and
lakes (clamps), etc. Contour obstacles include water-
courses and reservoirs, nature reserves, nature reserves
and other specially protected areas, as well as places un-
favorable in engineering and geological terms: swamps,
zones of distribution of weak soils and karst, areas of
landslides and scree, unstable ravines, areas of ava-
lanches and mudflows, etc [7].
Along with natural factors, some obstacles of a so-
cial nature also belong to contour ones: settlements, en-
gineering communications, valuable agricultural land.
The most favorable overcoming, crossing or bypassing
of high-altitude and contour obstacles determine the po-
sition of the so-called "fixed points" through which it is
desirable to pass the route of the projected railway.
Fixed points are the passing or lowest "saddles" of inter-
sected watersheds, the most convenient places for cross-
ing rivers, engineering communications, as well as cir-
cumvention of contour obstacles. Taking into account
the reference points and fixed points, options for the di-
rection of the projected line are outlined. The variants of
the direction of the projected HSR between the same ref-
erence points can be preliminarily estimated by the fol-
lowing indicators: the length of the variant, the number
and size of large watercourses crossed by the route, the
extent of geologically unfavorable sections, etc [8].
In general, the position of the reference points, and,
consequently, fixed points, may not be strictly defined.
Then the task of choosing the direction of the projected
line becomes more complicated and its solution will re-
quire more mutual coordination of the work of various
modes of transport, consideration of the expanded poly-
gon of the network of existing railways and other com-
munication routes, as well as the use of additional indi-
cators and criteria for evaluating options. The most com-
petitive variants of the HSR are adopted to further clar-
ify the position of the route between the reference points
and (or) fixed points, taking into account technical fac-
tors and natural features of specific design sites. The
technical factors that influence the direction and position
of the route include such important main technical pa-
rameters of the HSR as the set maximum speed of trains
and the guiding slope.
The maximum speed determines the position of the
route through the minimum required radius of curves
and the conditions for its entry into the terrain and the
system of situational restrictions. Due to the high cost of
each kilometer of a double-track electrified line, when
designing the HSR, one should strive to reduce its
length. Reducing the length of the HSR, in particular,
can be achieved by increasing the guiding bias. But this,
in turn, may lead to an increase in the cost of train traffic.
Reducing the length at a fixed value of the limiting
slope, as a rule, leads to an increase in the volume of
work (excavation, construction of culverts, etc.). How-
ever, under favorable topographic conditions (relief
without prolonged maximum ascents) this increase in
volumes can be compared with a decrease in the cost of
structures that depend on the length of the route (the up-
per structure of the track, SCB and communications, etc.).
The position of the route is also influenced by: environ-
mental requirements (location of specially protected nat-
ural areas, water protection zones and coastal protective
strips of water bodies, noise impact from train traffic,
migration routes of rare and valuable animals, etc.); fa-
vorable location of associated watersheds, river valleys
and gentle slopes; the presence of complex physical and
geographical phenomena (slope processes, wetlands,
ice, seismic impacts, etc.) and a number of additional
factors and conditions specific to the design area.
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