MODELLING AND MONITORING OF STRUCTURAL SAFETY OF UNIQUE UNDERGROUND STRUCTURES OF THE SEWAGE SYSTEM OF LARGE CITIES IN DIFFICULT GROUND CONDITIONS

2021 ◽  
Vol 12 (1) ◽  
pp. 30-45
Author(s):  
N. A Perminov

Anthropogenic and dynamic impacts on facilities of underground urban infrastructure increase at intensive development of megacities. The unique long-operating underground structures of sewage system require special protection against anthropogenic influence as their wear degree in difficult soil conditions reaches 70 % and more. Therefore, providing structural (mechanical) safety of underground structures of excessive level of danger and responsibility defines sustainable operation and future development of geotechnical infrastructure of the megacity in general. Long-term studying dynamics of changes of technical state of underground sewage structures of the megacity, long operating (for more than 70 years) in soft soils, allowed establishing regularities of influence of intensive anthropogenic and dynamic impacts on this process. For the first time, based on developed continuous models of defective structures potentially dangerous sections have been identified, they are subjected to manifestation of critical failures; ways of their correction are presented. Numerical simulation has defined borders of defectless joint operation of the system “target area - geomassif - underground structure". Scientific substantiation of boundaries of areas with potentially dangerous sections of underground sewage facilities with account of external anthropogenic and dynamic impacts constitutes the basis for elaborating regulations on safe development of geotechnical infrastructure of the historical area of St. Petersburg. The proposed methods of monitoring and protection of geotechnical infrastructure have been successfully used for many years by St. Petersburg Vodokanal in areas of influence of anthropogenic factors and objects under construction on underground structures, they ensure an optimal combination of sustainable operation and development of geotechnical infrastructures of megacities.

Author(s):  
Nickolai Perminov

Emperor Alexander I Saint-Petersburg State Transport University, Saint-Petersburg, RUSSIA Abstract: Simulation of the parameters of a defectless lifecycle of large caissons at the stage of their plunging into heterogeneous soil milieu allows considerable expansion of the area of rational use of underground areas of megacities for deep transport facilities and engineering infrastructure due to provision of structural safety and sustainable operation of a special underground structure. Mega sizes of an RC caisson allow creating open underground areas, unique in volumes and deepness. The analysis of behavior of a massive gravitational fencing caisson at its incrementing and plunging into heterogenenous soil milieu allowed identifying the nature of its non-linear and unsteady behavior. Unsteadiness of the processes of interaction of a large structure and soil milieu accompanied by geometrical changeability causes the necessity to create methods of adaptive control of strain- stress behavior of the system “gravitational large body - heterogeneous host medium” for decreasing aggravating influence of these effects on strength, deformability and reliability of the structure at the subsequent stages of its lifecycle. Due to joint step-by-step implementation of geotechnical and structural calculations a history of the processes of caisson-soil milieu interaction is modeled and the parameters of adaptive control of strain-stress behavior are predicted, thus providing conditions of controlled lowering. The paper demonstrates results of consistent implementation of the given concept at the lifecycle stages of the unique caissons for the sewage system of the megacity beginning from numerical modeling during design to computer models of control of strain-stress behavior of the system “large caisson - soil bulk” using the methods of geotechnology with subsequent monitoring provision of the defectless stage of construction.


Buildings ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 323
Author(s):  
Vachara Peansupap ◽  
Pisal Nov ◽  
Tanit Tongthong

The kingpost was a vertical element that was used to support the structural strut in the deep excavation. The structural kingpost was commonly arranged by experienced engineers who used two-dimensional construction drawings. Thus, it was still time-consuming and error-prone. Currently, an available construction program has been developed to arrange the structural kingpost by identifying the clash problems in the 3D environment. However, they have a limitation for detecting the clash that was unable to visualize the concurrent clashes between kingpost and many underground structures. Then, the engineer cannot see all the clash incidents with each kingpost and move the kingpost to avoid the clashes successfully. Since the kingpost arrangement was still an inefficient practice that was limited in the visualization aspect, this research used engineering knowledge and advanced construction technology to detect and solve the clashes between kingposts and underground structures. The methodology used engineering knowledge of kingpost arrangement to develop the system modules by using a rule-based approach. Then, these modules were developed into the system by using visual programming of Building Information Modelling (BIM). To test the system, an underground structure from building construction was selected as a case study to apply the developed system. Finally, the finding of this study could overcome human judgment by providing less interaction in the kingpost arrangement and visualization improvement of clash occurrences in the 3D model.


2005 ◽  
Vol 42 (2) ◽  
pp. 491-498
Author(s):  
Dae-Sang Kim ◽  
Kazuo Konagai

Earthquake observations at different sites within alluvial soil deposits have demonstrated that the motion of buried underground structures closely follows that of the surrounding soil. Therefore, it is usual in a seismic design process to apply free-field ground displacements through Winkler-type soil springs to an underground structure to evaluate stress patterns induced within its structural members. Using a simplified approach, this paper provides a clear understanding of resonant horizontal ground displacement of and strain in a surface soil deposit with a radical change of depth and of where they occur.Key words: simple approach, seismic design, earthquake, resonance, underground structures.


2018 ◽  
Vol 38 ◽  
pp. 03038
Author(s):  
Ran Liao

With the vigorous development of urban rail transit system, especially the construction of subway system, the safety of subway system draws more and more attention. The study of anti-seismic for underground structures has also become an important problem to be solved in the construction of Metro system. Based on the typical underground structure seismic damage phenomenon, this paper summarizes the seismic characteristics, research methods and design methods of underground structures to offer a guide for engineers.


2018 ◽  
Vol 182 ◽  
pp. 02063 ◽  
Author(s):  
Vladimir Kekelidze ◽  
Alexander Kovalenko ◽  
Richard Lednicky ◽  
Victor Matveev ◽  
Igor Meshkov ◽  
...  

The NICA (Nuclotron-based Ion Collider fAcility) is the new international research facility under construction at the Joint Institute for Nuclear Research (JINR) in Dubna. The main targets of the facility are the following: 1) study of hot and dense baryonic matter at the energy range of the maximum baryonic density; 2) investigation of nucleon spin structure and polarization phenomena; 3) development of JINR accelerator facility for high energy physics research based on the new collider of relativistic ions from protons to gold and polarized protons and deuterons as well with the maximum collision energy of sqrt(sNN) ~11GeV (Au79+ +Au79+) and ~ 27 GeV (p+p). Two collider detector setups MPD and SPD are foreseen. The setup BM@N (Baryonic Matter at Nuclotron) is commissioned for data taken at the existing Nuclotron beam fixed target area. The MPD construction is in progress whereas the SPD is still at the beginning design stage. An average luminosity of the collider is expected at the level of 1027 cm-2 s-1 for Au (79+) and 1032 cm-2 s-1 for polarized protons at 27 GeV. The status of NICA design and construction work is briefly described below.


2016 ◽  
Vol 53 (6) ◽  
pp. 988-999 ◽  
Author(s):  
Taous Kamel ◽  
Ali Limam ◽  
Claire Silvani

Old tunnels suffer from deterioration and it is necessary to assess their residual strength to properly organize their repair and strengthen them. The stress state of underground structures evolves over time, firstly because of the advancement of the working face during construction, then due to gradual changes in soil properties and mechanical properties of materials composing the infrastructures, such as reduction of cohesion, loss of strength and (or) stiffness, etc. These changes are caused by combined actions such as creep and (or) weathering processes as well as the appearance of cracks that induce redistribution of stresses and therefore strains. This study investigates tunnels and galleries of the Paris underground. Macromodeling based on the finite element method allows consideration of different scenarios of tunnel-lining deterioration, specifically at the extrados of the galleries or tunnels. To understand changes in the stress state, and also damage occurrence and associated redistributions (stress and strain), it is necessary to model the delayed deformations. To model the infrastructure behavior, a time-dependency approach has been chosen. This approach can quantify the damage and predict the residual strength of this type of underground structure. An elastic–viscoplastic constitutive model with strain-softening is used to reproduce the appearance of the degraded zones and their behavior. The results obtained with the numerical approach reproduce Paris metro tunnel behavior, corroborate geoendoscopy results, clarify their interpretation, and improve the management of infrastructure repairs.


Author(s):  
Oleg V. Mkrtychev ◽  
Yury V. Novozhilov ◽  
Anton Yu. Savenkov

At the objects of space infrastructure and at nuclear power facilities there are industrial structures, the main task of which is to protect a person, equipment or machinery from emergencies such as, for example, explosions, falling of various objects, fragments. In accordance with the requirements of the Federal Law On the Protection of the Population and Territories from Natural and Technogenic Emergencies, when calculating such structures, all types of loads corresponding to their functional purpose must be taken into account. So, for structures located in the area of a possible accident and the fall of space rockets, it is necessary to calculate for the fall of the destroyed parts of the rocket engine. For nuclear power plant facilities, such accidents occur when containers and other heavy objects fall on the ground, affecting underground structures located in the ground, and for civil defense protective structures built into the basement floors of buildings, it is necessary to consider situations in which the overlying floors of a building collapse when exposed to there is an air shock wave on them. Therefore, this problem is relevant, and in this study, a finite-element method for calculating an underground structure in a non-linear dynamic setting has been developed when a large overall object collides with the ground.


2018 ◽  
Vol 4 (11) ◽  
pp. 2756 ◽  
Author(s):  
Alireza Darvishpour ◽  
Asadollah Ranjbar ◽  
Amirmohammad Amiri

The passage of underground structures from the bottom of the structures on the ground causes a change in the stresses and strains created in the structure as well as the soil environment surrounding the tunnel due to the existence of an interaction between these two sides. In this way, the existence of the surface structure leads to a change in the strain and stress conditions around the tunnel, and in contrast, the tunnel also leads to a change in the stress and settlement around the structures. Therefore, such a reciprocal behavior is very important. In this research, with the help of Abaqus finite element software, two main possible conditions are considered: the creation of an underground structure in the presence of the superstructure, as well as the reverse state of the concept of constructing a building in the state in which the underground structure already exists. One of the subjects studied in this research is the physical modelling effect of the structure, rather than the effect of its wide load on the ground. Other parameters considered in this research are the number of story, the depth of the tunnel, the width of the tunnel, the thickness of the lining, the effect of changes in the soil parameters in the depth and the horizontal distance of the tunnel center from the building center. The results of this research are validated based on the results obtained by other researchers. According to the results obtained in this research, by the increase of the distance between the tunnel center and structure center and depending on the stiffness of the tunnel lining, significant asymmetric stresses are created in the superstructure. The construction of the structure before and after the tunnel construction can affect the unsymmetrical settlement of the structure The stress and strain created in the lining of the tunnel and the surrounding area are also different due to the amount of mobilized force in the reinforcements.


Author(s):  
Alexander M. Belostotsky ◽  
Pavel A. Akimov ◽  
Dmitry D. Dmitriev

As is known, underground facilities are an integral part of the infrastructure of modern society. These objects have some specific characteristics such as complex construction, high cost, long life cycle, etc. Once it is destroyed, the direct and indirect losses are more seriousness than the general structure in the ground. Under-ground facilities built in areas subject to earthquake activity must withstand both seismic and static loading. Therefore, it is very important to carry on the seismic design of the underground structure in a safe and economi-cal way. The distinctive paper presents a summary of the current state of seismic analysis for underground struc-tures. Classification and brief overview of methods of seismic analysis of underground structures (force-based methods, displacement-based methods, numerical methods of seismic analysis of coupled system “soil – under-ground structure”) are presented, problems of soil-structure interaction are under consideration as well. So-called static finite element method with substructure technique for seismic analysis of underground structures is de-scribed.


2021 ◽  
Vol 11 (23) ◽  
pp. 11245
Author(s):  
Ruijie Zhang ◽  
Dan Ye ◽  
Jianting Zhou ◽  
Dengzhou Quan

At present, the seismic design research of underground structures in loess areas is lagging behind compared with practical engineering requirements. The selection of seismic calculation methods and parameters does not consider the influences of the special geological conditions in various regions, so their usefulness is limited. Based on the above problems, a modified displacement-based method (DBM) was proposed and its application was compared with the most commonly used methods of analysis (force-based design method, displacement-based design method, detailed equivalent static analysis numerical method, and the full dynamic time-history method). The results were also validated by considering data from shaking table tests conducted on a case study involving the underground Feitian Road subway station in Xi’an. The results show that compared with DBM, the average accuracy of the modified DBM technique is improved by 41.65%. The modified DBM offers good accuracy, simplicity in its model, a rapid analysis time, and easy convergence.


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