Weihai Beach Holiday beings people took part of the second structural design go hand in hand
1 design information and design data structure layout 1.1 1.1.1 The main span and bridge span width criteria: l = 25 (m); calculated span: l0 = 20-0.4 2 = 24.2 (m); standard width : 3.75 6 + 0.75 2 = 24 (m) 1.1.2 design load cars -20 level; crowd: 3kN / m2; each side of the railing, sidewalk weight sysco boston were 1.52kN / m and 3.6kN / m. 1.1.3 Materials and construction technology of concrete: C45 concrete are used. Prestressing steel: The Strand sysco boston Φs1 7 shares. Ordinary steel: the use of HRB335 rebar. Plate: supporting plate anchor head, bearing plate, sysco boston are using ordinary A3 carbon steel. By making post-tensioned girder construction technology, the use of metal bellows and OVM anchor diameter 80. 1.1.4 Design sysco boston Basis highway engineering standard sysco boston (JTG B01-2003), People's Communications Press, 2004. Universal highway bridge design specifications (JTG D60-2004), People's Communications Press, 2004. Reinforced concrete and prestressed concrete highway bridges and culverts (JTG D62-2004), the people traffic. Press, 2004. 1.1.5 The basic calculation data table as shown in Table 2.1.1. The basic calculation data sheet 2.1.1 name Bullets Unit Data concrete cube strength C MPa 45 elastic modulus Ec MPa 3.25 design axial compressive strength fcd MPa 20.5 tensile strength ftd MPa 1.74 strand design standard modulus strength fpk MPa 1860 amount Ep MPa 1.95 tensile sysco boston strength fpd MPa 1170 design maximum control compressive stress sysco boston σcon MPa 1395 design value fpd 'MPa 390 material density reinforced concrete γ1 kN / m3 25 asphalt sysco boston concrete γ2 kN / m3 22 modulus of elasticity of steel beams and concrete dimensionless ratio αEP 6 1.2 1.2.1 cross-section arranged to determine the size of the main beam section detailing the beam height h 1: The main span beam height is usually 1 / 15-1 / 25, in order to reduce the bridge deck span (general restrictions within the 2m-3m). So by h = (1/16) l0 = (1 / 14.3) 24.20 = 1.750m, 2. the flange plate thickness is determined: in the small span prestressed concrete sysco boston simply supported beam, the upper flange plate The thickness is less than the height of the main beam 1/12. Currently, bridges and urban highway viaducts are set to crash on the railing, according to the requirements of the anti-collision, flange plate thickness not less than 200mm. In this design, take hf = 200mm 3. web thickness is determined: sysco boston the role of prestressed concrete beams prestressed and bent ribs, rib of the principal stress sysco boston smaller rib thickness is generally decided sysco boston by the constructor . Meanwhile, in order to improve the durability of the structure, appropriate to increase the thickness of the protective layer of reinforced concrete beams rib thickness in 160mm-400mm. So take b = 200mm. Determine sysco boston the thickness of the bottom flange 4: lower flange T-shaped cross-section reinforced concrete simply supported beam ribs and other general and wide. To meet the layout tendons and withstand tensile stress of the requirements phase, the lower edge of prestressed concrete T-beam sysco boston should be expanded to make a horseshoe. Horseshoe area should not be too small, generally 10% -20% share of the total cross-sectional area. Horseshoe total width is about 2-4 times the width of the rib, the design district three times, that is 600mm. Lower flange height plus half the height of the ramp area of about 0.15-0.20 times higher beam. Steep slopes sysco boston should be at 450. 5 inner flange width and the calculation of wide flange calculated bf1 = l0 1/3 = 24.2 1/3 = 8.07 (m) bf2 = number of lanes in each lane width / (total estimate of the number of beams -1) = 6 3.75 / [(3.75 6 + 1 2) /2.2-1] = 2.020 (m), whichever is the lesser value, too bf = 2.000 (m) outer flange bf1 = 0.9 + 0.09 + hf number of lanes = 0.9 + 0.09 + 0.200 6 = 2.190 (m) bf2 = 0.9 + 0.09 + 0.67 = 1.660 (m), whichever is the lesser value, but to facilitate the construction taking bf = 1.600 ( m) within the beam and pivot-sectional dimensions shown 2-1-1,2-1-2: sysco boston Figure 2-1-1 within the beam cross-section units (mm)
Figure 2-1-2 fulcrum sectional units (mm) Figure 2-1-3 Supports T-beam map units (mm) 1.2.2 calculating sysco boston cross-sectional geometry of the main beam cross-section is divided into five rules in a small cell, cross-sectional geometry Feature List is calculated in Table 2-1-2.
Note: Ai is the number of cross-sectional area; ai ask for T beam centroid distance between the bottom edge; Si to ask T-beam cross-section of the bottom edge of the area moments; Iia demand for the T-beam cross-section of the bottom of inertia Iio to ask for its cross-sectional shape of the mandrel inertia; moment. sysco boston 1.2.3 eigenvalues of the total cross section can be obtained from Table 2-1: An = 8.3 105mm2 Yn = ΣSi / An = 8.605 108 / 8.3 105 = 1.036 102mm In = ΣIio + ΣIia-YnΣSi = 3.484 1010 + 1.182 1012-1.036 102 8.605 108 = 1.217 1012mm4 1.3 cross-section changes along the span girder only use high form, the cross-section of the T-beam sysco boston flange thickness along the span length unchanged, horseshoe sysco boston section In line with the steel beams bent near the span of four points from the start to gradually raise the fulcrum. Beam ends due to the role of anchor head concentrated force caused by the larger local stress, but also for the arrangement sysco boston of anchor needs, within sysco boston the range of 88cm from the end of the beam will be thickened to a horseshoe with a web width. At the beginning of the thickened section sysco boston of the web from the fulcrum to is 150cm, which is set for a long transition section thickening web of 100cm. 1.4 beam diaphragm settings lateral distribution of the beam diaphragm can load more reasonable. In order to reduce the main beam design plays a major role in controlling cross the moment, in a cross-
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