Calculation of monolithic bridges taking into account seismic conditions of Republic of Uzbekistan
←
→
Page content transcription
If your browser does not render page correctly, please read the page content below
E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
Calculation of monolithic bridges taking into
account seismic conditions of Republic of
Uzbekistan
Ulugbek Shermukhamedov*, Anora Karimova, Abdurakhim Abdullaev, and Inobat
Hikmatova
Tashkent State Transport University, Tashkent, 100067, Uzbekistan
Abstract. To improve the transport infrastructure of the Republic of
Uzbekistan, the monolithic structure of bridges and overpasses began to be
used. The article presents the calculation of a monolithic overpass on the
1083rd km of the M-39 highway passing through Samarkand. The results
of the calculation of a monolithic overpass from dynamic load are
presented based on the records of two real seismograms for two dangerous
earthquakes for the system with spectral composition: Gazli (Uzbekistan)
and Manjil (Iran). The calculations show that to ensure guaranteed seismic
safety of transport structures, it is necessary to carry out design
calculations based on sets of records of earthquakes that occurred, close in
dominant frequencies to the characteristics of the construction site. Such a
provision should be introduced into the relevant regulatory documents.
1 Introduction
The importance of the transport logistics system in today's globalized world economy is
even greater. Developing a logistics system that meets modern requirements is one of the
signs of a country's prosperity. Railways, roads, bridges, tunnels, and other artificial
structures built on these roads can be indicated as the main part of the logistics system.
Providing citizens of our country with convenient and high-quality transport services and
ensuring the stable operation of transport and communication systems are important for the
development of our state. Today, construction is considered a promising plan for the
development of the economy of the Republic of Uzbekistan. The modern construction
industry is one of the most prominent national sectors of the economy of the Republic of
Uzbekistan, showing stable annual growth.
In a speech at a joint meeting of the chambers of the Oliy Majlis, the President of the
Republic of Uzbekistan Sh.M. Mirziyoyev "From the Action Strategy to the Development
Strategy: Priority Tasks Implemented as part of the Development Strategy", a special place
was given to the construction industry as a locomotive of the economy for the further
accelerated development of the construction of buildings and artificial structures on
railways and roads.
*Corresponding author: ulugbekjuve@mail.ru
© The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative
Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
As part of the implementation of the Decree of the President of the Republic of
Uzbekistan dated October 4, 2019 No. DP-3309 "On improving the system for organizing
the construction and operation of road bridges, overpasses, and other artificial structures, "
dated November 27, 2018 No. DP-4035 "On measures to introduction of advanced foreign
methods of organizing work in the construction and operation of roads", work is underway
to build roads and bridges to ensure safe traffic.
In this regard, in recent years, there has been an increased interest in the world in the
modernization and expansion of the road network, including bridge structures, using
modern technologies and designs of bridges and overpasses made of monolithic reinforced
concrete. Although monolithic construction began its development relatively recently, this
construction method is considered the most promising at present. Monolithic bridges are
used in all developed countries of the world. Monolithic construction is a method of
erecting buildings and structures, in which the main material of the structures is monolithic
reinforced concrete. The reinforced concrete structure is strong and durable and also has
high performance. The main feature of monolithic construction is that the place for
producing material for monolithic bridges and other engineering structures is a construction
site. The use of monolithic reinforced concrete makes it possible to realize a variety of
architectural forms and reduce steel consumption by 7-20% and concrete by up to 12%. In
addition, there are several advantages of this method:
– construction speed. This method allows you to install supports very quickly and move
on to the next stage of construction;
– reliability. A monolithic reinforced concrete structure, made in strict accordance with
the technology, has increased strength and resistance to design loads;
– price. Because the technological process of monolithic construction is quite fast and
economical in terms of resources, the cost of work on this technology is much lower than
that of possible analogs;
– it is possible to create complex geometric shapes, i.e., many construction companies
are convinced that superstructures made of prestressed monolithic reinforced concrete,
along with undeniable technical and economic advantages, also have aesthetic appeal. And
this is especially important for a city world-famous for its beauty.
To date, to improve the transport infrastructure of the Republic of Uzbekistan, they
began to use the monolithic structure of bridges and overpasses. One of the clearest
examples of this is the new overpass, which is being built on the 1083rd km of the M-39
highway passing through the city of Samarkand, which is being built by the Kuprikkurilish
Trust UE, which is a structural subdivision of Uzbekistan Temir Yollari JSC. The total
length of the overpass is 110 meters, and the width is 28.9 meters. The overpass will be
divided into 3 lanes on each side with a width of 3.5 meters.
Another example is the construction in Tashkent of a six-lane highway and three
overpasses that connect the Sergeli district with the central part of the city [1]. The overpass
construction, which shortly will become another excellent example of the creativity of
architecture, is carried out based on the latest technologies following international
standards.
It is known that the territory of Central Asia, especially Uzbekistan, is a seismically
active zone. As a result, the design and construction of bridges, overpasses, and overpasses
must be subject to high requirements. In this regard, it is of interest to develop methods and
software for calculating bridges and overpasses for the effect of earthquakes based on the
available seismic records [2, 3]. Seismic isolating devices are used to dampen vibrations
under seismic impacts [3].
Currently, in Uzbekistan, for the design of earthquake-resistant structures, there are
current standards KMK 2.01.03-19, and for transport facilities - ShNK 2.01.20-16
"Construction of transport structures in seismic areas". However, in the section of the new
2E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
ShNK 2.01.20-16 concerning bridges and overpasses, there are practically no issues of
special seismic protection in the calculations of bridges for seismic effects.
Carrying out calculations based on the available real records of seismograms [4],
recorded during strong earthquakes and stored in well-known databases in Europe and the
USA, makes it possible to study the behavior of the structure in real-time, as well as to
evaluate the strength of the elements of calculated bridges and overpasses. This approach
will ensure the reliability of bridges and overpasses under seismic effects that have a certain
intensity at the construction site.
2 Methods
More than twenty monographs have been published on the issues of seismic isolation of
buildings and bridge structures. The classification of seismic isolation devices is given by
scientists and specialists V.A. Verkholin [5], A.M. Uzdin and T.A. Sandovich [6], G.S.
Shestoperov [7], R. Skinner, W. Robinson, and G. Mtsverri [8] and other authors. In [9], the
issues of seismic isolation and seismic damping of bridges, considering the features of
seismic vibrations of bridges, assessing seismic loads, and setting the design impact and
coefficients of seismic and moving loads combinations are considered.
The three-span reinforced concrete monolithic overpass, 110 m long and 10.5 m wide,
has a variable thickness along the overpass. The overpass design is divided into finite
elements, taking into account the change in height along the span length. The finite element
models axial tension-compression, bending about axes perpendicular to the longitudinal
axis of the overpass, and torsion about the longitudinal axis [10, 11]. The span structure of
the overpass is made by a continuous monolithic reinforced concrete design scheme of 33m
+ 42m + 33m of individual design. On the facade, the superstructure is made with a slab of
variable height - 1.3 m in the span and 2.3 m above the support.
Bridge structures consist of many elements, the most important of which are supports
and supporting parts [12]. The support and supporting parts are the bridge structure's most
vulnerable elements; therefore, seismic isolating devices, particularly rubber-metal ones,
are used for the supporting part. The supporting part is a seismic insulating rubber-metal
device. Due to low shear rigidity, it allows the span to move in the longitudinal direction in
the range from 0.1 m to 0.35 m, depending on the models used. The vertical stiffness of the
supporting part is 5.908x109 H/m; the horizontal stiffness is 4.72x106 H/m. The bearing
part is modeled as a finite element operating in tension/compression, shear in two
directions, and torsion. Intermediate supports have dimensions: height of 5.85 m, width
along the facade - 2 m, and in the lateral direction, it has a variable height from 5 m to 8.4
m. In this calculation, we assume their movement is equal to the movement of the base
during an earthquake. The material of all structures is concrete of class B35 in strength,
with specific gravity γ = 25000 N/m3, elastic modulus E = 35200 MPa, and Poisson's ratio
= 0.2.
The seismicity of the territory of Samarkand, according to the map of seismic
microzoning made by the Institute of Seismology in 1980, is estimated at 9 and 8 points.
The site of the projected construction is located in the 8-point zone.
Following Table 1.1 of KMK 2.01.03-96 within site in the upper 10-meter thickness,
counting from the base of the foundations, soils of the II category in terms of seismic
properties occur - loams with a porosity coefficient eE3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
Fig. 1. Scheme of a monolithic overpass passing at 1083 km of the M-39 highway
Fig. 2. General view of the intermediate support
In [13-15], studies were conducted in detail on the method of calculating damped
systems; the effectiveness of using the mass damper setting to reduce damage after strong
earthquakes was obtained.
Recently, seismograms of earthquake records have been taken as seismic impacts [16,
17]. It is interesting to develop methods and software for calculating bridges and overpasses
for earthquake impacts based on the available seismic records.
3 Results and Discussions
The impact is set in the form of a series of seismogram records in three directions with
amplitude adjustment for different intensities. The equation of motion of the structure after
applying the discretization by the finite element method is reduced to the form
[]{̈ } + ƞ[]{̇ } + [ ]{} = { }, (1)
with initial conditions from the static solution of the problem
4E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
{( )} = [(0)], ( ̇ )
= {̇ (0)}, (2)
where {u(t)} is the vector of absolute displacements of the nodal points of the finite
element model of the structure; for nonlinear problems, the matrices [M], [C], [K] depend
on the absolute displacement vector, {P(t)} includes the specified movement soil and
forces. Ground motion is specified in seismogram records [2, 18-21].
The seismic action is transmitted to the structure at four points through the supports in
the form of equal displacements of the supports and the base surface. At the beginning of
the overpass - the left end of the span is rigidly connected to the abutment, and at the end of
the overpass - the right end is connected to the abutment with movable bearing parts.
The article presents the results of calculations of a monolithic overpass from the
dynamic load based on the records of two real seismograms of dangerous earthquakes:
Gazli (Uzbekistan) and Manjil (Iran).
Gazli (Uzbekistan) earthquake dated May 17, 1976, more than 9 points on the MSK-64
scale, maximum acceleration, velocity, and displacement in the direction of seismic wave
propagation: 7.22 m/s2; 0.62 m/s; 0.18 m. Vertical acceleration 14 m/s2.
Manjil (Iran) earthquake of 06/20/1990, 8 points on the MSK-64 scale, maximum
acceleration, speed, and displacement in the direction of seismic wave propagation: 1.93
m/s2; 0.21 m/s; 0.064 m
The calculation was carried out by the finite element method according to the beam
theory; the Newmark method was used for the time variable. The need to carry out
calculations for the seismic resistance of unique structures, as well as structures with
seismic isolating devices using records of accelerograms and seismograms (displacements)
of the soil surface, required the modification of the SHARK software (prof. I. Mirzaev
created the software package), which meets the modern needs of researchers and designers
in the field of construction in seismic regions [2].
For discretization, the overpass was divided into 220 finite elements, taking into
account the operation of each type of finite element. The calculations were carried out using
an implicit scheme with a time step of 0.005 s. The energy loss is taken into account in the
Rayleigh form.
Earthquake records are taken from the European Strong Earthquake Database [21, 22].
On fig. 3 shows the longitudinal movement of the right end of the overpass (black line),
which is free from longitudinal stress, and the movement of the corresponding abutment
from active soil pressure (red line) during the Gazli earthquake.
It can be seen from the graph that the maximum displacement in a seismic wave
propagating along the longitudinal axis of the overpass is 0.18 m. The seismic wave
propagation velocity is 500 m/s. In this case, the maximum difference between
displacements is 0.07 m, and at a seismic wave propagation velocity of 250 m/s, this
displacement difference will be 0.14 m. This is due to the difference in wave propagation
velocities in the monolithic structure of the overpass and in the ground, which leads to a
delay in the arrival of the wave along the ground. It follows that the bearing part of the right
end of the overpass does not allow the span to fall from the abutment because the maximum
displacement of the rubber-metal bearing part is 0.2 m.
5E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
Fig. 3. Change in time of the longitudinal movement of the right end of the overpass span and base
(Gazli earthquake)
For comparison, the behavior of the overpass structure was also calculated during the
Manzhil earthquake. In this case, the maximum difference between displacements is 0.03
m, and at a seismic wave propagation velocity of 250 m/s, this displacement difference will
be 0.06 m.
On fig. 4 shows a graph of the change in time of the vertical movement of the overpass
span in the middle of the first and second spans during the Gazli earthquake.
Fig. 4. Change in time of the vertical movement of the overpass span in the middle of the first (black
line) and second (red line) spans (Gazli earthquake)
Here, the vertical displacements of the monolithic overpass are indicated at a distance of
16.5 m from the left end with a black line and at a distance of 54 m from the left end with a
red line. The maximum displacement is 0.21 m, which is associated with a large vertical
6E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
acceleration value in the earthquake record, equal to 14 m/s 2. In the middle of a large span,
high-frequency oscillations are observed. A separate comparison of the graphs of vertical
displacements of the upper part of the support and the corresponding point of the
monolithic overpass showed that the vertical component of the seismic wave tosses the
monolithic part of the overpass over the support by fractions of millimeters [23]. In this
case, the bearing parts work in tension, which may cause high-frequency oscillations.
Figure 5 and figure 6 show the changes in time of the vertical shear force and bending
moment relative to the horizontal axis of the overpass span above the first intermediate
support during the Gazli earthquake.
On figure 5 shows the change in time of the vertical shear force of a monolithic
overpass at a distance of 33 m from the left end, i.e., above the support. The maximum
absolute value is 13.3 MN; the static value is - 6.7 MN.
Change in time of the bending moment relative to the horizontal axis of the cross-
section of a monolithic overpass at a distance of 33 m from the left end, i.e., above the
support, shown in figure 6. Maximum value 79.76 MNm, static value 46.89 MNm.
Fig. 5. Change in time of the vertical shearing force of the overpass span above the first intermediate
support (Gazli earthquake)
Change in time of the bending moment relative to the horizontal axis of the cross-
section of a monolithic overpass at a distance of 33 m from the left end, i.e., above the
support, shown in fig. 6. Maximum value 79.76 MNm, static value 46.89 MNm.
7E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
Fig. 6. Change in time of the bending moment relative to the horizontal axis of the overpass span
above the first intermediate support (Gazli earthquake)
Figure 7 shows the change in time of the longitudinal stress at a distance of 54 m from
the left end of the overpass span at the midpoint along the width under the upper surface
(black line) and above the lower surface (red line) during the Gazli earthquake. This
seismic wave causes the stress to increase more than twice the static stress value. After the
passage of a seismic wave, the voltage quickly returns to a static state.
Fig. 7. Change in time of the longitudinal stress at a distance of 54 m from the left end of the overpass
span (Gazli earthquake)
On figure 8 shows the change in the vertical shear force along the overpass at different
times (t=14.26 s; t=15.77 s; t=18.25 s; t=20.45 s) during the Gazli earthquake. In this
figure, you can see the oscillatory change in the shear force during an earthquake.
8E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
Fig. 8. Change in the vertical shear force along the overpass at different points in time (Gazli
earthquake)
On figure 9 shows the change in the bending moment relative to the horizontal axis
along the overpass at different times (t=14.26 s; t=15.77 s; t=18.25 s; t=20.45 s) during the
Gazli earthquake. In this figure, you can also see the oscillatory change in the bending
moment.
Fig. 9. Change of the bending moment relative to the horizontal axis along the overpass at different
times (Gazli earthquake)
4 Conclusion
The current regulatory documents on the earthquake-resistant construction of transport
facilities do not reflect the seismic resistance of structures, taking into account multi-level
design. Unfortunately, in transport construction, domestic design institutes do not use
records of real earthquakes in the calculations of bridges for seismic resistance and are
9E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
limited to linear-spectral calculations due to the lack of information about the situational
seismicity of the territory of Uzbekistan. In this regard, to ensure the guaranteed seismic
safety of transport facilities, it is required to carry out design calculations on sets of records
of occurred earthquakes that are close in dominant frequencies to the characteristics of the
construction site. This provision must be included in the relevant regulatory documents.
References
1. Shermukhamedov U.Z., Kadirova Sh.Sh., Abdullayev A.R. Vybor ratsional'nykh
variantov konstruktsii metro estakady goroda Tashkent. Mezhdunarodnaya nauchno-
prakticheskaya konferentsiya «Novyye tekhnologii v mostostroyenii (NTM - 2022)».
SPb, 2022.
2. Rashidov T.R., Kuznetsov S.V., Mardonov B.M., Mirzayev I. Prikladnyye zadachi
seysmodinamiki sooruzheniy. Kniga 1. Tashkent.: Navruz, s. 268. (2019)
3. Shermukhamedov U.Z. Gasheniye prodol'nykh seysmicheskikh kolebaniy opor
balochnykh mostov s seysmoizoliruyushchimi opornymi chastyami. Monografiya.
Tashkent.: s. 180. (2020)
4. Mirzaev I., Bekmirzaev D. Earthquake resistance assessment of buried pipelines of
complex configuration based on records of real earthquakes. Soil Mechanics and
Foundation Engineering, 57(6), pp. 491-496 (2021) https://doi.org/10.1007/s11204-
021-09697-0.
5. Verkholin V.A Osobennosti rascheta i podbora parametrov seysmoizolyatsii mostov.
Seysmostoykoye stroitel'stvo. Bezopasnost' sooruzheniy. № 2. s. 44-48. (2004)
6. Uzdin A.M., Sandovich T.A., Al'-Naser-Mokhomad Samikh Amin. Osnovy teorii
seysmostoykosti i seysmostoykogo stroitel'stva zdaniy i sooruzheniy. S. Peterburg:
Izd.VNIIG, s. 175. (1993)
7. Shestoperov G.S. Obzornaya informatsiya. Antiseysmicheskiye ustroystva v
mostostroyenii. M.: VPTITRANSSTROY, s. 46 (1986)
8. Skiner R.I., Robinson W.H., McVerry G.H. An introduction to seismic isolation. Ney
Zeuland. John Wiley and Sons. p. 353 (1993)
9. A.M. Uzdin, I.O. Kuznetsova. Seysmostoykost' mostov. Kniga. Palmarium Academic
Publishing. s. 456 (2014)
10. Myachenkov V.I., Mal'tsev V.G., Mayboroda V.P. Raschot mashinostroitel'nykh
konstruktsiy metodom konechnykh elementov, M.: Mashinostroyeniye, s. 520 (1989)
11. Shaposhnikov N.N., Tarabasov A.D., Petrov V.V., Myachenkov V.I. Raschot
mashinostroitel'nykh konstruktsiy na prochnost' i zhestkost'. M.: Mashinostroyeniye, s.
264 (1984)
12. Alatyrtseva Ye.L., Uzdin A.M., Dolgaya A.A., Shermukhamedov U.Z., Shul'man S.A.
Seysmoizolyatsiya zheleznodorozhnogo mosta v Uzbekistane. Nauchno-tekhnicheskiy
zhurnal. «Prirodnyye i tekhnogennyye riski. Bezopasnost' sooruzheniy». – SPb.: RF. №
1. s. 33-37, (2021)
13. A. Benin, A. Uzdin, O. Nesterova. Efficiency of using tuned mass damper to reduce
damage after strong earthquakes. MATEC Web of Conferences 239, (2018).
https://doi.org/10.1051/matecconf/201823905014
14. C.S. Lee, K. Goda, H.P. Hong. Effectiveness of using tuned-mass dampers in reducing
seismic risk. Structure and Infrastructure Engineering, 8(2), pp. 141-156 (2012)
https://doi.org/10.1080/15732470903419669.
10E3S Web of Conferences 365, 02005 (2023) https://doi.org/10.1051/e3sconf/202336502005
CONMECHYDRO - 2022
15. U. Shermuxamedov, S. Saliхanov, S. Shaumarov, F. Zokirov. Method of selecting
optimal parameters of seismic-proof bearing parts of bridges and overpasses on high-
speed railway lines. European Journal of Molecular and Clinical Medicine, 7(2), pp.
1076-1084, (2020)
16. I. Mirzaev, A. Yuvmitov, M. Turdiev, J. Shomurodov. Influence of the Vertical
Earthquake Component on the Shear Vibration of Buildings on Sliding Foundations.
E3S Web of Conferences 264, (2021) https://doi.org/10.1051/e3sconf/202126402022.
17. E. Kosimov, I. Mirzaev, D. Bekmirzaev. Comparison of the impacts of harmonic and
seismic waves on an underground pipeline during the Gazli earthquake. IOP Conf.
Series: Materials Science and Engineering 1030 (2021) doi:10.1088/1757-
899X/1030/1/012082.
18. Ulugbek S., Saidxon S., Said S., and Fakhriddin Z. Method of selecting optimal
parameters of seismic-proof bearing parts of bridges and overpasses on high-speed
railway line. European Journal of Molecular & Clinical Medicine, 7(2), pp. 1076-1080.
(2020)
19. Shermuxamedov U., Shaumarov S., and Uzdin AUse of seismic insulation for seismic
protection of railway bridges. E3S Web of Conferences, 264, (2021)
20. Rashidov T. R., Tursunbay R., and Ulugbek S. Features of the theory of a two-mass
system with a rigidly connected end of the bridge, in consideration of seismic influence
on high-speed railways. European Journal of Molecular and Clinical Medicine, 7(2),
pp. 1160-1166. (2020)
21. Uzdin A.M., Kuznetsova I.O. Seysmostoykost' mostov. Kniga. Saarbryuken
(Germaniya), Palmarium, s. 450 (2014)
22. Ambraseys N.N., Smit P., Douglas J., Margaris B., Sigbjörnsson R., Ólafsson S.,
Suhadolc P., Costa G. Internet site for European strong-motion data. Bollettino di
Geofisica Teorica ed Applicata, 45(3) (2004)
23. Mirzaev I., A. Yuvmitov, M.Turdiev and J. Shomurodov. Influence of the Vertical
Earthquake Component on the Shear Vibration of Buildings on Sliding Foundations.
E3S Web of Conferences 264, (2021), https://doi.org/10.1051/e3sconf/202126402022
11You can also read
