The structural strength of roads and streets as well as the uniformity of strength are ensured by a design strength of subgrade, sub-base and pavement layers, characterized by a deformation modulus, the value of which depends on the properties of materials used for the pavement structural layers and thickness of the layers. During construction of road or street pavement structure and its operation the continuous static and dynamic vehicle loads may cause the intermixing of the subgrade soil with the frost blanket course. Analogical process could happen between the frost blanket course and the sub-base constructed from the large particles of aggregate. Eventually, the intermixed materials of the different structural layers of road or street can have the impact on the strength and durability of the whole structure. In order to prevent the aggregates of different structural layers from becoming intermixed during road or street construction or in the phase of operation the geotextile inter-layers have been world-widely used in the recent 15 years. Based on the recommendations of U.S. researchers the geotextiles used for the separation of structural layers should be selected according to the existing formulas. However, these formulas are valid only for the road structures without asphalt concrete pavement. Another method for selecting geotextiles – specifications and recommendations of different countries. At present there are no generally accepted European specifications... [to full text] / Įrengiant automobilių kelio ar gatvės dangas ant žemės sankasos bei vėliau jas eksploatuojant dėl nuolatos pasikartojančių statinių bei dinaminių transporto priemonių apkrovų gali prasidėti žemės sankasos grunto bei apsauginio šalčiui atsparaus sluoksnio medžiagų sąmaiša. Analogiškas procesas gali vykti ir tarp apsauginio šalčiui atsparaus sluoksnio bei dangos pagrindo medžiagų. Ilgainiui kelio ar gatvės konstrukcijos sluoksnių medžiagų tarpusavio sąmaiša mažina dangos stiprį bei tvarumą. Siekiant išvengti atskirų konstrukcijos sluoksnių mineralinių medžiagų tarpusavio susimaišymo, tiesiant kelius ar gatves bei juos eksploatuojant, pastaruosius 15 metų pasaulyje plačiai taikomi geotekstilės tarpsluoksniai. Jungtinių Amerikos Valstijų mokslininkai geotekstiles parinkti rekomenduoja naudoti skaičiavimus pagal formules, tačiau jos tinka tik keliams be asfaltbetonio dangos. Kitas geotekstilių taikymo būdas – atskirų šalių sukurtos normos bei rekomendacijos. Europoje nėra vieningų norminių dokumentų, reglamentuojančių geotekstilių naudojimą automobilių kelių bei gatvių konstrukcijos sluoksniams atskirti. Tai galima pagrįsti tuo, kad Europos valstybėse yra skirtingos klimatinės bei geologinės sąlygos. Taigi kiekviena ar keletas valstybių, kurioms pagal jų sąlygas aktualu kelio konstrukcijos sluoksnius atskirti geotekstilėmis, turi savo normas ar rekomendacijas. Lietuvoje geosintetinės medžiagos tiesiant ir rekonstruojant automobilių kelius bei miestų gatves naudojamos tik... [toliau žr. visą tekstą]

Abstract This thesis deals with the developing of fibre-optic instruments for monitoring the health of civil engineering and composite structures. A number of sensors have been tested for use with different road structures, concrete bridges, fibre reinforced polymer (FRP) containers and other composite specimens, the interrogation methods being mainly based on measuring optical power and time-of-flight (TOF). The main focus is on the development of a fibre-optic TOF measurement system and its applications, but different sensing needs and fibre-optic measurement systems are also reviewed, with the emphasis on commercial devices. Deformation in a road structure was studied with microbending sensors of gauge-length about 10 cm and a commercial optical time domain reflectometer (OTDR) in a quasi-distributed fashion. The responses of the optical fibre sensors during the one-year measurement period were similar in shape to those obtained with commercial strain gauges but the absolute measurement values typically deviated by several tens of per cent. Low dynamic range, crosstalk and poor signal-to-noise ratio proved to be the main problem when measuring several successive sensors with an OTDR. In another road investigation, microbending and speckle sensors were found useful for providing on/off-type information for traffic control applications. FRP composite containers were investigated with the focus on developing a continuous monitoring system for improving yield and quality by evaluating the state of cure during the manufacturing process and for assessing damage, e.g. delaminations, during service life. Standard multi-mode and single mode fibres with a typical length of a few hundreds of metres were embedded inside the walls of containers during the normal manufacturing process, and the measurements were carried out using an optical through-power technique and an OTDR. This largely empirical investigation revealed that the coating material and its thickness have an effect on loading sensitivity and on the applicability of the method for cure monitoring. The measurement data also indicated that the end-of-curing process and the location of external damage can be determined with a distributed optical fibre sensor and an OTDR. Several versions of a pulsed time-of-flight measurement system were developed for interrogating sensor arrays consisting of multiple long gauge-length sensors. The early versions based on commercial electronics were capable of producing relevant measurement data with a reasonable precision, but they suffered especially from poor spatial resolution, low sampling rate and long-term drift. The high precision TOF system developed in this thesis is capable of measuring time delays between a number of wideband reflectors, such as connectors or fibre Bragg gratings (FBG), along a fibre path with a precision of about 280 fs (rms-value) and a spatial resolution of about 3 ns (0.30 m) in a measurement time of 25 milliseconds. By using a fibre loop sensor with a reference fibre, a strain precision below 1 με and a measurement frequency of 4 Hz can be achieved. The system has proved comparable in performance to a commercial FBG interrogation system in monitoring the behaviour of a bridge deck, while the fact that it allows static and dynamic measurements with a number of long gauge-length sensors, also embedded in FRP composite material, makes this TOF device unique relative to other measurement systems.

The aim of this thesis is to design an exclusion of the road crossing the railway line no.300 with Kaštanová street in Brno. A ring road-based solution is proposed. Planned doubling of railway line, as mentioned in the feasibility study of SJKD, was taken into account. The new railway station Brněnské Ivanovice is designed, which will together with public transport bus services create an interchange station. The project also includes a newly designed routes for pedestrians.

This thesis is focused on possibilities of financial valuation of flexible pavements surface layers conditions, in connection with whole life cycle of the pavement and certain possibilities of their maintenance and repairs, in cases of defects and failures from forensic engineering point of view. There were carried out analysis of the topics connected with judging of flexible pavements surface layers defects and failures related to forensic investigation in the Czech Republic, as well as abroad. In this thesis there were created pricing models of the certain construction works which are related to repairs and maintenance of flexible pavements. Within the possibilities of the author, there were compared market prices of the particular construction works in selected regions with the prices according to generally used pricing systems in the Czech Republic. The goal of this thesis is to create unified methodology for amount of damage financial valuation in cases of defects and failures of flexible road pavements surface layers for forensic engineering practice in the Czech Republic.