Analysis and modelling of the seismic behaviour of high ... - Ingegneria

More documents

Recommendations

Info

5. SEISMIC BEHAVIOUR OF RC COLUMNS EMBEDDING STEEL PROFILES 5.3 Description of the prototype structure The prototype structure considered in this study is shown in Figure 5.4. It is a 5- storey, 30.0m long x 12.0m wide x 21.0m high structure, which includes six equal two-bay moment resisting frames with different bay length (5m and 7m), as illustrated in Figure 5.4a. In the direction perpendicular to the main moment resisting frames, simply supported secondary beams are foreseen at column lines to provide a better out of plane resistance. The structure was thought as a moment resisting (MR) type without core system, shear walls or other kinds of sub–structure able to transfer downwards the horizontal forces when subjected to the seismic load combinations and as having a core system resisting horizontal loads when subjected to the static load combinations. From a finite element analysis and design of this prototype structure the overall geometrical and mechanical properties of the columns of the first floor will be determined. 7000 5000 6000 6000 6000 6000 6000 (a) (b) Figure 5.4. (a) Plan and (b) lateral view of the building 5.3.1 Materials and mechanical properties The material classes adopted in the design are: • Concrete: Class C 25/30 400 550 100 700 n° 260 n° 302 n° 309 The mechanical properties of the concrete used in the design are the same as those reported in Table 3.1 of Eurocode 2. Wherever relevant, the beneficial 179
5. SEISMIC BEHAVIOUR OF RC COLUMNS EMBEDDING STEEL PROFILES 180 effects of the concrete confinement due to the presence of the stirrups are taken into account (Mander, 1988). The concrete confinement results in a modification of the effective stress-strain relationship: higher strength and higher critical strains are achieved (see Figure 5.5). The other basic material characteristics are considered as unaffected for the design. Figure 5.5. Stress-strain relationship for confined concrete • Steel rebars: Class B 450 C Following the prescription reported in Section 5.3.2.(1) and 5.4.1.1.(3) of the Eurocode 8 (2001), when considering critical parts of primary elements in seismic design, reinforcing steel bars of class B and C as indicated in Table 3.3 of Eurocode 2 shall be used. Consequently, the following properties are guaranteed: Characteristic yield strength fyk: 450 MPa k = (ft / fy)k: 1,15 < k < 1,35 Characteristic strain at maximum force euk (%): > 7,5% • Structural Steel: Class S 235 When the design of steel structural members is required, the use of Structural Steel Class S 235 will be implied. Following the prescription of Eurocode 8 (2001), the possibility that the actual steel yield strength will be higher than the value of the nominal yield strength is taken into account by a material over strength factor γov equal to 1.25. In structural members designed with the purpose of dissipating seismic energy, the value of the material yield strength utilised during the erection of the building must not exceed fymax = 1.1.γov times the yield strength defining the material steel grade: e.g., for S235 class not higher than ≈320MPa. As an alternative way, it is allowed to determine the actual yield strength of the material utilised for the structure, taking it as the effective value in the design verifications. Having considered these prescriptions we are to use a steel grade S235 with a fy = 355 MPa, value
Page 1 and 2:
Dipartimento di Ingegneria Meccanic
Page 3 and 4:
UNIVERSITÀ DEGLI STUDI DI TRENTO D
Page 6:
Ai miei genitori
Page 10 and 11:
INDEX 1 INTRODUCTION...............
Page 12 and 13:
INDEX iii 4.10.3 Results of the PsD
Page 14 and 15:
1.1 Introduction 1 1 INTRODUCTION I
Page 16 and 17:
1. INTRODUCTION imposes precise con
Page 18 and 19:
1. INTRODUCTION joints whilst 2D mo
Page 20 and 21:
7 2 DUCTILITY AND SEISMIC RESPONSE
Page 22 and 23:
2. DUCTILITY AND SEISMIC RESPONSE O
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
3. SEISMIC BEHAVIOUR OF BOLTED END
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97:
Page 98 and 99:
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Page 106 and 107:
Page 108 and 109:
Page 110 and 111:
Page 112 and 113:
Page 114 and 115:
4. SEISMIC RESPONSE OF PARTIAL-STRE
Page 116 and 117:
Page 118 and 119:
Page 120 and 121:
Page 122 and 123:
Page 124 and 125:
Page 126 and 127:
Page 128 and 129:
Page 130 and 131:
Page 132 and 133:
Page 134 and 135:
Page 136 and 137:
Page 138 and 139:
Page 140 and 141:
Page 142 and 143: 4. SEISMIC RESPONSE OF PARTIAL-STRE
Page 188 and 189: 5. SEISMIC BEHAVIOUR OF RC COLUMNS
Page 242 and 243:
5. SEISMIC BEHAVIOUR OF RC COLUMNS
Page 244 and 245:
Page 246 and 247:
Page 248 and 249:
Page 250 and 251:
Page 252 and 253:
Page 254 and 255:
Page 256 and 257:
Page 258 and 259:
6. SUMMARY, CONCLUSIONS AND FUTURE
Page 260 and 261:
Page 262:
show all

Analysis and modelling of the seismic behaviour of high ... - Ingegneria

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?