Martin Stolárik

Seismic impact of the railway on the geotechnical constructions

Nowadays, the focus on more ecological means of material and persons transport is still higher. Big loads can be transported on railways more effectively and with lower environment impact than on roads. The geotechnical structures are inherent parts of railway infrastructure, such as embankments, sides of notches and, of course, tunnels, foundation constructions of buildings or pillars of bridges and the others geotechnical constructions (e.g. retaining walls, culverts, transition area of bridges). By train pass, vibrations are caused and these vibrations are relayed to the soil. These vibrations can make adverse impact to surrounding objects and to technologies placed in. This so far uncared-for influence gets into the foreground by current trend of everyday life technical equipment increasing. The article introduces different kinds of geotechnical structures and the influence of by-passing railway transport on their constructions and surroundings. The data are evaluated in the amplitude and frequency domain.

Dynamic effect of harmonic vibrations: various approaches to monitor

The undesirable dynamic effects of harmonic vibrations due to various devices and technologies are commonly monitored using by seismic stations operating on the principle of mechanical vibration systems (using on horizontal foundation structures or rock mass) or by resistance strain gauges (using e.g. on vertical concrete or steel elements). Modern, progressively evolving alternative to monitor these dynamic effects are methods based on fiber-optic principle. There is used fiber Bragg grating (FBG) or fiber-optic interferometric sensors. At the experimental level the article presents results comparison of conventional approaches to the monitoring of harmonic vibrations and approaches based on fiber-optic principle. Data was process in both amplitude and frequency domain.

Comparison of measurements of the rail transport impact on the rock environment using a classical seismic sensor and fiber-optic interferometric sensor

Road car transport is today the main species of cargo and passenger transport. However, car transport is accompanied by large negative effects with adverse environmental impacts. Therefore, it is an effort to shift part of the transported costs to rail transport. But the problem is vibrations which created the passing vehicles. The vibrations are transmitted over the rails and the railway infrastructure into the rock environment. These vibrations can adversely affect buildings around the railroad. This article presents a comparison of vibration measurements using a classical commonly used seismic sensor and innovative fiber-optic interferometric sensor. Presented results are based on the real measurements of train traffic. Presented results can serve as a basis for mathematical models which predict the future load of objects in the vicinity of railway tracks.

Numerical modeling and measurement of polydimethylsiloxane deformation with fiber Bragg grating sensor

This paper deals with mechanical properties of polydimethylsiloxane (PDMS) as material for preparation of deformation sensors. PDMS is widely used especially in medical area. Some application of PDMS as material for preparation of deformation sensors with fiber optics has been prepared. Due to its hyper-elastic and viscoelastic of this material is complicate to use it with long time and large deformation mechanics. In this paper authors compare the numerical models of prepared sensor using hyper-elastic models and mechanical experiment at large deformation.

Parametric Study on the Effects of Soil to Oscillation Velocity / Parametrická Studie Vlivu Typu Zeminy Na Amplitudu Rychlosti Kmitání

Abstract The paper focuses on the possibility of evaluating the influence of character of the soil to oscillations velocity induced dynamic loads. Mathematical modeling is used to solve the parametric study. Models are created in software Plaxis 2d based on finite element method. Dynamic load is based on experimental measurements on the stand in the area of the Faculty of Civil Engineering, VSB-TUO. Soil properties are determined from the normative indicative characteristics. Abstrakt Příspěvek je zaměřen na možnost posouzení vlivu charakteru zemin na amplitudu rychlosti kmitání vyvolanou dynamickým zatížení. Pro řešení parametrické studie je využito matematického modelování ve výpočetním programu Plaxis 2D založeného na metodě konečných prvků. Dynamické zatížení vychází v příspěvku z experimentálního měření provedeného na standu v areálu Fakulty stavební, VŠB-TUO. Vlastnosti zemin vycházejí ze směrných normových charakteristik.

Seismic Response Hydraulic Hammer on the Secundary Lining Tunnel / Seizmická Odezva Hydraulického Bouracího Kladiva Na Definitivní Ostění Tunelu

Abstract Construction and subsequent tunnels collapse of the Jablunkovsk’s pass are already among well known of the professional public. After the collapse left part of the tunnel already standing with secondary lining. The second part was temporarilied concrete secured stopper and heavy bridge formwork. During the progress of work was already reached that stage when plug must be removed. The stopper was removed by combination of blasting operations and hydraulic hammer. This article deals with seismic effect hydraulic hammer. It is therefore a unique measuring effect of vibration on the final tunnel lining. A vibration downturn was monitored in the first meters of the lining and the records were evaluated in the amplitude and frequency resort. This assessment was made on the basis CSN 73 0040. Abstrakt Výstavba a následná havárie tunelů v Jablunkovském průsmyku jsou již mezi širokou odbornou veřejností dobře známy. Po havárii zůstala část tunelu stát s již vybudovaným definitivním ostěním. Druhá část byla provizorně zajištěna betonovou zátkou a těžkým mostním bedněním. Při postupu prací se již dosáhlo etapy, kdy musí být zátka odstraněna. K odstranění se používá kombinace trhacích prací a hydraulického bouracího kladiva. Tento článek se zabývá seizmickým vlivem hydraulického bouracího kladiva. Jedná se tedy o unikátní měření vlivu vibrací přímo na definitivní ostění tunelu. Byl sledován útlum vibrací v prvních metrech ostění a získané záznamy byly vyhodnoceny v amplitudové i frekvenční oblasti. Vyhodnocení bylo provedeno na základě ČSN 73 0040.