Ojačitev nevezanih nosilnih slojev voziščnih konstrukcij s prostorsko mrežno strukturo trakov

doktorska disertacija na študijskem programu 3. stopnje UM

Samo Peter Medved (Author), Bojan Žlender (Mentor), Stanislav Lenart (Co-mentor)

Abstract

Voziščne konstrukcije so najpomembnejši element vsake prometnice in tisti del, od katerega je najbolj odvisna varnost, in nivo uporabe prometnice. Prav tako je element, ki pomeni bistven investicijski element pri vsaki gradnji prometnice in element, v katerega se največkrat posega, vzdržuje, obnavlja … Čeprav se zdi, da gre za enostavno konstrukcijo, tako po izboru materialov, tehnologiji gradnje kot matematičnemu modelu za analizo konstrukcije, pa v praksi vse do danes nismo uspeli učinkovito rešiti probleme trajnih deformacij voziščnih konstrukcij. Kljub razvoju materialov v zadnjem obdobju, vsaj kar se tiče vezanih nosilnih plasti, pa problemi voziščnih konstrukcij ostajajo enaki, malo je inovativnih rešitev in modelov. Nevezane nosilne plasti imajo izrazito slabost, da niso sposobne prevzeti nateznih napetosti v horizontalni ravnini. Zaradi tega prihaja do plastičnih deformacij, ki se posledično prenašajo na površino vozišča v obliki razpok in kolesnic. Kljub preoblikovanju naravnega kamnitega materiala in dodajanjem veziv, se še posebej pri preobremenitvah ali poslabšanih hidrogeoloških pogojih naravnih temeljnih tal, ne moremo izogniti vertikalnim deformacijam vozišča, ki so posledica prekomernih horizontalnih napetosti v nevezanih plasteh voziščne konstrukcije. Reševanje z uporabo ojačitvenih mrež (geomrež) v horizontalnem nivoju nevezanih nosilnih plasti, ne da želenih rezultatov, saj prihaja do strižnih deformacij med nivoji ojačitev. V zadnjih letih pa vse do danes, je ideja doživela velik razvoj v smeri 3D struktur vertikalno nameščenih trakov - geocelic. Vezane deformabilne obrabno-nosilne plasti v kombinaciji z geocelicami ojačenimi nevezanimi nosilnimi plastmi zemljin predstavljajo učinkovit inovativen sistem voziščne konstrukcije, ki s svojo sestavo zagotavlja trajno elastičnost, fleksibilnost in zadostno nosilnost same konstrukcije. Eksperimentalna analiza je pokazala bistveno izboljšanje nosilnosti in zmanjšanje deformacij z uporabe mrežne strukture vertikalnih trakov geocelic. Uporabljen material za takšno strukturo, pa je lahko v celoti uporabljen iz recikliranih sintetičnih materialov, kar je z uporabo lokalnih gradbenih materialov lahko tudi pomemben prispevek ekološki gradnji, manjši porabi energije in zmanjšanju emisij v okolje.

Keywords

voziščne konstrukcije;geocelice;geosintetiki;nevezani nosilni sloji;fleksibilne vozliščne konstrukcije;mrežne strukture;načrtovanje;doktorske disertacije;Voziščne konstrukcije;Disertacije;Deformacije;Ojačitve;

Data

Language:	Slovenian
Year of publishing:	2016
Typology:	2.08 - Doctoral Dissertation
Organization:	UM FGPA - Faculty of Civil Engineering, Transportation Engineering and Architecture
Publisher:	[S. P. Medved]
UDC:	624.159.4:625.87.074.5(043.3)
COBISS:	19670550
Views:	1436
Downloads:	151
Average score:	0 (0 votes)
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Other data

Secondary language:	English
Secondary title:	REINFORCEMENT OF THE PAVEMENT CONSTRUCTIONS FROM UNBOUND SOIL MATERIAL WITH GRID SYSTEM FROM VERTICAL STRIPS (GEOCELLS)
Secondary abstract:	Pavement structure is the most important element of every traffic infrastructure, it is the element on which safety and the level of usage depends most. Pavement structure is also the most crucial element investment wise, since it needs most interventions, maintenance work and repairs. Eventhough it seems like pavement structure is material wise, construction technology wise and mathematical analytic formula wise a very simple structure, in practice we still haven't successfully solved the problems of pernament deformations of the pavement structures. Despite the progress in materials in the last period, at least regarding bound up bearing layers, pavement structure problems remain the same, there are very few innovative solutions. Unbound bearing layers have a distinct weakness that they are not capable of bearing tensile tension in horizontal plain. This results in plastic deformations that transmit on surface of the pavement as cracks and ruts as a consequence. Despite the transformation of natural grevel and sand materials and adding binders, we can't avoid vertical deformations of the pavement that are the consequence of an excessive horizontal tensions in detached layers of the pavement construction, especially when overloading, or in case of deteriorated hydro-geologic conditions of the natural ground. Solving the problem using geogrids on horizontal level of the detached supporting layers did not give the results we hoped for because shear skids were occurring between the levels of reinforcement. From the very beginning of the idea, till today, the idea experienced a great development in the direction of 3D structures; vertically placed strips - geocells. Binded deformed defensively-supporting layers in combination with geocell reinforced unbound bearing layers of earth represent effective and innovative system of pavement structure with it's structure that guarantee permanent elasticity, flexibility and adequate bearing strength of the construction itself. Experimental analysis showed a crucial improvement of the bearing strength and reduction of deformation when using geogrids. The material, used for that kind of structure can be fully made out of recycled synthetic materials, which can be, with usage of local construction materials, an important contribution to ecological building, reduced consumption of energy and reduction of environmental emissions.
Secondary keywords:	pavement;geocells;geosynthetics;pavement structure;unbound bearing layers;flexible pavement;grid structures;geomash;
URN:	URN:SI:UM:
Type (COBISS):	Doctoral dissertation
Thesis comment:	Univ. v Mariboru, Fak. za gradbeništvo, prometno inženirstvo in arhitekturo
Pages:	XV, 194 str.
ID:	9122036