Civil Engineering

This paper discusses the results of in situ vibration measurements that have been performed during the homologation tests of the line L2 of the high speed train (HST) track between Brussels and Köln. Measurements have been performed on both tracks and in the free field during the passage of an IC train and a Thalys HST at variable speed. The results will subsequently be used to validate the numerical prediction models.

Some problems regarding numerical modeling of predicted vibrations excited by railway traffic are discussed. Model formulation in the field of structural mechanics comprises a vehicle, a track (often in a tunnel) and soil. Time consuming computations are needed to update large matrices at every discrete step. At first, a sequential Matlab code is generated. Later on, the formulation is modified to use grid computing, thereby a significant reduction in computational time is expected.

Przedmiotem niniejszego artykułu jest określenie niektórych cech dynamicznych gruntu wpływających na propagację fali sprężystej. Wykorzystano tutaj informacje uzyskane z dynamicznych badań powierzchniowych, wykonanych w przekroju gruntowym za pomocą różnego typu wymuszeń impulsowych oraz sondowań wgłębnych. Analizowano propagację fal sprężystych w gruncie oraz obliczono, stosując Metodę Elementów Brzegowych, odpowiedzi dynamiczne gruntu dla parametrów uzyskanych z badań.

This paper focuses on the results of in situ vibration measurements that have been performed prior and during the homologation tests of the line L2 of the high speed train (HST) track between Brussels and Köln. Several experiments have been performed in order to determine the track and the soil dynamic characteristics. The vibrations have been measured during the passages of an IC train and a Thalys HST at variable speed. Furthermore, it is briefly outlined how the free field vibrations can be predicted by means of a numerical model that accounts for the dynamic interaction between the train, the track and the soil. A preliminary validation of the model using experimental results is performed.

Landslides in the Carpathian flysch have a peculiar susceptibility to activation. This is due to the geological structure of the flysch. This study addresses analysing the effects of a landslide, particularly in regards to the operation of a transportation route that runs through the Carpathian flysch. The studies include both field work and laboratory testing of basic geotechnical parameters. The field work comprises surveys made by a terrestrial laser scanner. The study also includes a number of 2–D and 3–D numerical models. Subsequently, survey results and an analysis of the effects of landslide susceptibility and the behaviour of the road and terrain surface, due to the different loading conditions, are shown.

Terrestrial laser scanning helps us to detect unstable subsurface behaviour, assessing the slope stability and potential landslide failure modes. If the slopes are regularly observed, the risk of slope movement and subsequent consequences may be considerably reduced. This allows for optimum land use conditions that are economically justified. Landslides in the Carpathian flysch have a peculiar susceptibility to activation due to the region’s geological structure. This work addresses the problem of monitoring and analysing the effects of landslides associated with the operation of routes (roads and railway lines) running through the slopes of the Carpathian flysch. The terrestrial laser scanner enables site remote sensing in a simple and automated manner. Regular measurements with multiple scanner positions may be used for long term slope monitoring. A detailed geological structural model allows for risk assessment with regards to failure modes, and it allows for a slope stability as...

Przedmiotem artykułu jest system pomiarowy wykorzystywany w badaniach laboratoryjnych osiadań gruntu. System zbudowany jest z wielu elementów (modułów) składowych, pozwala kontrolować przebieg różnych eksperymentów. Szczególnie przydaje się w przypadku długotrwałych (wielodniowych) badań. Przykładem takich badań są laboratoryjne badania gruntu zalecane przez normy krajowe oraz europejskie. Zaprezentowano również wyniki badań przeprowadzonych przy użyciu tego systemu pomiarowego.

Docelowe wartości poziomów (wskaźników) niezawodności według różnych zaleceń normowych krajowych i międzynarodowych nie są spójne. Zalecane wartości wskaźników niezawodności są zwykle podawane dla jednego lub dwóch okresów odniesienia (1 rok i 50 lat), bez wyraźnego odniesienia do projektowanego okresu użytkowania. W artykule podjęto próbę wyjaśnienia związku między wymaganym wskaźnikiem niezawodności i projektowanym okresem użytkowania oraz określenia zależności pomiędzy docelowym poziomem niezawodności dla zadanych konsekwencji zniszczenia a projektowanym okresem użytkowania i stopą dyskontową. Analizowano zalecenia zawarte w PN-EN 1990, PN-ISO 2394 i JCSS: 2001. Probabilistic Model Code. Ze wspomnianych tutaj norm/dokumentów nie wynika wyraźny związek między projektowanym okresem użytkowania i docelowym poziomem niezawodności. Analizując niezawodność w odniesieniu do projektowanego okresu użytkowania można stwierdzić, że zwiększenie jakości i niezawodności powoduje wzrost kosztów realizacji/wybudowania obiektu budowlanego, sprawia jednak, że maleją koszty użytkowania, eksploatacji i straty wynikające np. z pojawiających się uszkodzeń obiektu podczas użytkowania. Dokonując weryfikacji docelowych wskaźników niezawodności według różnych zaleceń normowych, krajowych i zagranicznych, można stwierdzić, że optymalne wskaźniki niezawodności zależą przede wszystkim od stosunku kosztów awarii konstrukcji (koszty nieprawidłowo użytkowanej konstrukcji), natomiast mniej istotny wpływ na projektowany okres użytkowania i docelowy wskaźnik niezawodności według M. Holicky'ego ma wartość stopy dyskonta nieruchomości.

In recent years, there is an increase of landslide risk observed, which is associated with intensive anthropogenic activities and extreme weather conditions. Appropriate monitoring and proper development of measurements resulting as maps of areas at risk of landslides enables us to estimate the risk in the social and economic aspect. Landslide monitoring in the framework of SOPO project is performed by several methods of measurements: monitoring of surface (GNSS measurement and laser scanning), monitoring in-deepth (inclinometer measurements) and monitoring of the hydrological changes and precipitation (measuring changes in water-table and rainfall).

Due to the significant role and noticeable development of transportation routes running from the north to the south of central Europe, several problems related to the construction and functioning of roads in the Carpathian foothills have been revealed. Recent climate change causes areas, where transport routes are particularly exposed to hazards, to succumb to technical exploitation and degradation. The elimination of the threats related to the activation of landslide phenomena becomes particularly expensive. Old roads, which were once designed for significantly lower axle loads and less heavy traffic conditions, are predominantly exposed. At the present, these roads are heavily exploited and have become overloaded. As a result, both the roadway and the subgrade undergo damage, which causes an increase in dynamic loads, and in potentially endangered areas, the activation of landslides. Landslides in the Carpathian flysch have a peculiar susceptibility to activation due to its geolog...

The aim of the work is to acquire the answer for a question if, and to what extent the dynamic excitation forced by underground movement of metro carts or another vibration source impacts the condition of the existing building. To get that assessment, a corresponding numerical model of the tunnel and soil and the structure is created. As input, the acceleration response spectrum computed for the Gulf of Aquaba earthquake is used, as well as the quasi-static axle loading of typical metro carts. The output is shown as the time-history response of the ground-level nodes that will later be used to assess the influence of vibrations with the help of Ciesielski (SWD) scales.

The main activity of open pit mining of aggregates are aggregates' exploitation of natural mineral deposits and its modification in order to obtain high-quality aggregates. The development of aggregate production is conditioned by a number of factors. The most important are: documented material resources, mining and manufacturing capabilities, the need of environmental protection (environmental aspects), the subordination of the plan of spatial development, formal and legal issues, as well as economic and financial aspects. While identifying and assessing the environmental impacts of manufacturing aggregates one may distinguish those environmental aspects that have or may have the greatest magnitude of the impact on the environment as a result of industrial activities. Manufacturers producing aggregates located in the areas covered by the special environmental protection require extra diligence in the conduct of mining activities for preservation of natural resources. The article discusses some main environmental aspects of the production of construction aggregates on the example of one of the largest producers of this material in Subcarpathian province of Poland. Environmental protection in production of aggregates may refer to four aspects: the use of natural resources, having excluded land from agriculture and forestry, land reclamation after exploitation, and use of energy from renewable energy sources. The economic and environmental impact of production volume of aggregates is evaluated by the index information capacity method and the method of graphs.

At present, the requirements for thermal insulation of the external walls in buildings are being increased. There is a need to reduce energy consumption for heating rooms during the winter season. This may be achieved by increasing the thermal resistance of the outer partitions, using solutions that utilize either recuperation or solar radiation. The most popular systems include either solar collectors, or heat pump links or ground exchangers. Trombe walls (TW) are a very promising passive heating system, which requires little or no effort to operate, and may be very convenient in different climate conditions. A typical TW consists of a masonry wall painted a dark, heat absorbing paint colour and faced with a single or double layer of glass. The principle of operation is based on the photothermal conversion of solar radiation. There are various modifications of TW. They may improve the energy efficiency in relation to the climate conditions in which they operate. The hybrid solutions are also known. The efficiency of walls is related to the use of proper materials. In TW, the compromise should be sought between the thermal resistance and the ability to distribute heat from the absorbed energy of solar radiation. The paper presents an overview of the most commonly used solutions and discusses its own concept dedicated to the climate conditions of Central Europe.