Analiza strižne nosilnosti sodobne zidovine ob upoštevanju predlaganih sprememb za Evrokod 6 : diplomska naloga

Filipčič, Eva (author), Bosiljkov, Vlatko (mentor), Klun, Martin (comentor)

Zidovina je konstrukcijski material, za katerega je značilno, da dobro prenaša tlačne obremenitve, dosti slabše pa strige in natege. Najbolj tipična strižna obremenitev, ki lahko prizadene zidane stavbe je potres. Potresno delovanje je na območju Slovenije zelo aktivno. Ravno zato je kontrola strižne nosilnosti zidanih stavb pri nas izredno pomembna. Zahteve in načela za določanje nosilnosti zidanih konstrukcij so podane v standardu Evrokod 6: Projektiranje zidanih konstrukcij – 1-1. del: Splošna pravila za armirano in nearmirano zidovje (SIST EN 1996-1-1, 2006), ki pa ne definira standardnih preizkusov, s katerimi bi lahko določili strižno nosilnost zidovine kot kompozitnega materiala. Podane so le empirične enačbe, ki temeljijo na porušnih mehanizmih zidanih elementov. V izdelavi je nova izdaja 1-1. dela standarda Evrokod 6 (prEN 1996-1-1, 2018), ki prinaša spremembo v karakterističnem koeficientu trenja ^^, ki nastopa v enačbi za izračun strižne trdnosti zidovja ^^^. Sedanji standard Evrokod 6 (SIST EN 1996-1-1, 2006) podaja njegovo vrednost, v novem predlogu standarda Evrokod 6 (prEN 1996-1-1, 2018) pa je ta vrednost le priporočena in obravnavana kot nacionalni parameter. V sklopu diplomskega dela smo na podlagi baz podatkov rezultatov alternativnih strižnih preiskav narejenih na Fakulteti za gradbeništvo, Univerze v Ljubljani in Zavodu za gradbeništvo, računali vrednosti karakterističnega koeficienta trenja, ki bi jih na podlagi preizkusov lahko določili kot nacionalne parametre za določevanje strižne trdnosti zidovine. Rezultati izračunov ^^ na podlagi podatkov strižnih preiskav zidov se razlikujejo za votle zidake in zidake skupine 1 z 0 % in 25 % lukenj. Pri polnih zidakih z 0 % lukenj bi bilo ob upoštevanju strožjih varnostnih zahtev za račun strižne odpornosti zidovine smiselno upoštevati nižje vrednosti karakterističnega koeficienta trenja: ^^ = 0,3 ali ^^ = 0,35. Vrednost ^^ = 0,4 se pri votlih zidakih in zidakih s 25 % lukenj izkaže za ustrezno.

• Language: Slovenian
• Keywords: zidovina, strižna trdnost, standardi Evrokod, karakteristični koeficient trenja
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Publisher: [E. Filipčič]
• Year: 2019
• PID: 20.500.12556/RUL-110456
• UDC: 006.82:624.041.6(043.2)
• COBISS.SI-ID: 8896097
• Publication date in RUL: 15.09.2019

Secondary language

• Language: English
• Title: Assessment of the shear resistance of the contemporary masonry according to proposed changes in Eurocode 6 : graduation thesis

Abstract

Masonry as a material is much more resistant to compressive loads than tension and shear loads. Earthquake is the most common shear load that can affect masonry buildings. Seismic activity in Slovenia is very high. That is why it is extremely important to properly asses the shear resistance of masonry buildings. Detailed rules for determining load carrying capacity of building and civil engineering works in masonry are given in part 1-1 of standard Eurocode 6: Design of masonry structures – Part 1-1: General rules for reinforced and unreinforced masonry structures (SIST EN 1996-1-1, 2006). Standard Eurocode 6 does not define any standard tests for determining shear strength of masonry structural elements. It provides empirical equations which are based on failure mechanisms of masonry elements. A new proposal of part 1-1 of standard Eurocode 6 (prEN 1996-1-1, 2018) is in preparation. One of the adjustments regarding shear strength of masonry elements relates to the characteristic coefficient of friction ^^, which appears in the equation for calculating characteristic shear strength of masonry elements ^^^. In the current standard Eurocode 6 (SIST EN 1996-1-1, 2006) the value of the characteristic coefficient of friction ^^ is prescribed, however the new proposal of the standard Eurocode 6 (prEN 1996-1-1, 2018) provides recommendations so that the value can be defined as a national parameter. In this graduation thesis the value of the characteristic coefficient of friction ^^ is determined from the data bases of the results of various alternative shear tests done on masonry walls specimens at the Faculty of Civil Engineering, University of Ljubljana and at the Slovenian national building and civil engineering institute (ZAG). The results of ^^ calculations are different for Groups 1 and 2 units. For masonry made with group 1 units with 0 % volume of the holes with strict safety requirements values ^^ = 0,3 or ^^ = 0,35 are appropriate. Whereas for group 2 and group 1 units with 25 % volume of the holes value ^^ = 0,4 is on the safe side.

• Keywords: masonry walls, shear strength, Eurocode standards, the characteristic friction coefficient