Tratto dalla Rivista IoRoma o dal suo allegato Quaderno che è consultabile al sito: http://rivista.ording.roma.it
a cura di 3F9: : .H?G9DIBG 3F9: : 2>99JIDJ commissione !IGEIBFJBH visto da: 3F9: : ): %0)<<DI=G 3F9: ,: G;;IEEJ
VERIFICA DI CAPACITÀ PORTANTE DI FONDAZIONI DIRETTE IN FASE SISMICA "H 7IDJ<JBH @J BH?HBJE+ ?GDEHFEI @J <GF@H;JGFJ @JDIEEI JF <HAI AJA=JBH6 BG=I DJB4JIAEG @HCCI * .-// 6 FIBIAAJEH C0H@G;JGFI @J G??GDE>FI <GD=>CI A7J8 C>??HEI H ?HDEJDI @H JF@H9JFJ A?IDJ=IFEHCJ I AE>@J EIGDJBJ B4I EIF9HFG BGF8 EG @I9CJ I<<IEEJ @ICC0H;JGFI AJA=JBH A>C AJAEI=H EIDDIFG8<GF@H;JGFI: Premessa , BH>AH @ICCI <GD;I @J JFID;JH JF@GEEI @HC AJA=H FIC EIDDIFG HC @J AGEEG @ICCH <GF@H;JGFI @JDIEEH AJ ?> =HFJ<IAEHDI >FH DJ@>;JGFI @IC BHDJBG CJ=JEI: ,C =G=IFEG CH FGD=H FGF <GDFJABI IA?CJBJEH JF@JBH8 ;JGFI A> &>HCI =IEG@G >EJCJ;;HDI ?ID CH 7IDJ<JBH @J BH?HBJE+ ?GDEHFEI JF <HAI AJA=JBH6 CHABJHF@G @J8 ABDI;JGFHCJE+ HC ?DG9IEEJAEH: 3F CIEEIDHE>DH BG=?HJGFG @J7IDAJ =IEG@J EDH B>J J =IEG@J @J .HABGFI6 HGC>BBJ IB ID6 H>9IDJ I 2JB4HD@A B4I 7IDDHFFG EDHEEHEJ JF AI9>JEG:
Verifiche agli stati limite ultimi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"H .JDBGCHDI ?DGAI9>I <GDFIF@G JF@JBH;JGFJ A>J ?HDH=IEDJ @H =G@J<JBHDI FIC BHCBGCG @IC BHDJBG CJ=JEI #?HDH9DH<G :55: : :5': Metodo di Cascone J1CJG9DH<JBH=IFEI6 JC =IEG@G B4I ?J AJ H77JBJ8 FH H &>HFEG @IABDJEEG FICCH .JDBGCHDI &>ICCG @J .HABGFI B4I IA?CJBJEH @>I <HEEGDJ BGDDIEEJ7J @H H??CJBHDI HC BGI<<JBJIFEI * @J BH?HBJE+ ?GDEHF8 EI AEHEJBG: effetto cinematico effetto inerziale
Tabella 1 - Coefficienti parziali R per le verifiche agli stati limite ultimi STR e GEO di muri di sostegno (tab. 6.5.I NTC2008) VeriďŹ ca
CoefďŹ ciente parziale (R1)
CoefďŹ ciente parziale (R2)
CoefďŹ ciente parziale (R3)
.H?HBJE+ ?GDEHFEI @ICCH <GF@H;JGFI
2 $ 5:/
2 $ 5:/
2 $ 5:
BGDDJ=IFEG
2 $ 5:/
2 $ 5:/
2 $ 5:5
2IAJAEIF;H @IC EIDDIFG H 7HCCI
2 $ 5:/
2 $ 5:/
2 $ 5:
Tabella 2 - Coefficienti parziali R per le verifiche agli stati limite ultimi di fondazioni superficiali (tab. 6.4.I NTC2008) VeriďŹ ca .H?HBJE+ ?GDEHFEI BGDDJ=IFEG
CoefďŹ ciente parziale (R1) 2 $ 5:/
CoefďŹ ciente parziale (R2) 2 $ 5:
CoefďŹ ciente parziale (R3) 2 $ -:
2 $ 5:/
2 $ 5:5
2 $ 5:5
Altri metodi di calcolo della capacitĂ portante di fondazioni dirette in condizioni sismiche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etodo di Paolucci e Pecker 3C =IEG@G EJIFI BGFEG @I9CJ I<<IEEJ BJFI=HEJBG I JFID;JHCI >AHF@G >F H??DGBBJG BJFI=HEJBG #FG8 EG BG=I yield design theory' I BGFAJ@IDH CH BH8 ?HBJE+ ?GDEHFEI JF BH=?G AJA=JBG ?DG@GEEG @IC 7HCGDI JF BH=?G AEHEJBG I @J EDI BGI<<JBJIFEJ <>F8 ;JGFI @HC BHDJBG GDJ;;GFEHCI @IDJ7HFEI @HCCH AG8 7DHAED>EE>DH6 @HCC0JFID;JH @IC EIDDIFG I @HCC0IB8 BIFEDJBJE+ @IC BHDJBG:
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J9>DH 5( Dati iniziali per il dimensionamento della fondazione nel caso in esame.
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J9>DH -( Variazione della larghezza B della fondazione e del coefficiente di sicurezza FS in funzione del metodo adottato nei due approcci considerati.
Esempio numerico 3F &>IAEG ?HDH9DH<G 7JIFI H<<DGFEHEG >F BHAG @J ?DHEJBH ?DG9IEE>HCI JFIDIFEI JC @J=IFAJGFH=IFEG @ICCH <GF@H;JGFI @JDIEEH @ICCH A?HCCH @J >F AGEEG8 ?HAAG6 BGF<DGFEHF@G J =IEG@J ?DIBI@IFEI=IFEI
J9>DH ( Confronto dei risultati ottenuti dallâ&#x20AC;&#x2122;applicazione dei vari metodi nei due approcci considerati per la determinazione della larghezza B della fondazione dellâ&#x20AC;&#x2122;esempio in esame.
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Per ulteriori articoli della presente pubblicazione IoRoma, consultare il sito: http://rivista.ording.roma.it
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