Hainan Steel News: Earthquake critical accounting multilayered steel plant construction
When seismic checking, considering only horizontal seismic effects and the construction of two spindles were checking directions, each direction horizontal seismic effect should be borne entirely by the seismic component of the direction. The effect of horizontal seismic base shear method can be used or modal response spectrum method of accounting. When accounting, in a multi earthquake, damping ratio can be selected 0.035; in rare earthquake, damping ratio 0.05 can be used.
Plant gravity load representative value and combination factors, in addition to compliance with the rules in Chapter 3, but still comply with the following rules:
(1) floor maintenance load should not be less than 4kN / m2, load factor combined value of 0.4 is preferable;
(2) the accumulation of finished goods or raw materials appearances load value according to the actual selection, the load factor of the combined value of 0.8;
(3) Equipment and material inside the hopper fullness chosen according to the actual operating conditions, when the material for the intermittent feeding, the combined value of the coefficient of material gravity load is taken as 0.8;
(4) pipe material gravity load drawn by the actual operating conditions, the combination of the value of coefficient of 1.0. Hainan Steel
Direct support equipment and hoppers member and cohesion, in addition to accounting dynamic vibration equipment load, there should be credited to the support member and the convergence of gravity earthquake effect. Equipment and hopper to the support member and the convergence of horizontal seismic effects can be determined as follows:
Fs = аmaxλGeq
λ = 1.0 + Hx / Hn
Where: Fs-- equipment or horizontal seismic effects at the standard value of the hopper center of gravity;
аmax-- maximum horizontal seismic influence coefficient;
Geq-- equipment or hoppers gravity load representative value;
λ-- amplification factor;
Hx-- base to the center of gravity away from the device or hopper;
From the bottom to the top of the building Hn-- basis of.
This horizontal seismic effects
Moment of the support member generated torque, take the device to a support member or hopper center of gravity away from the centroid accounting.
Multilayer steel structure plant load effect combinations according to Chapter 3 of the relevant rules of conduct.
Layout than the rules of the multi-layer construction, which accounted for the selection of plane transverse structure calculation model, when the flat floor is not rigid rules and the floor, the choice of accounting model space; accounting plant longitudinal structure, according to column column method of accounting , when each column column longitudinal stiffness vary greatly and rigid floor slab, the choice of space overall accounting model. There are pressure plate situ reinforced concrete floor, the board is smaller and the convergence with openings stud when steel beams and other pieces of cohesion and shear, floor regarded as a rigid floor.
The effect of the accounting effects of the earthquake, the choice of interlayer accounting model, while pressing a different envelope structure reduction factor to consider natural cycle Ψ. When the light block and precast wall hanging, Ψ 0.9; when the heavy masonry outsourcing, Ψ 0.85; when the heavy masonry wall inlay puzzle when, Ψ take all enclosure wall only 0.8 meters the quality, do not consider the stiffness and seismic work together. When constructing the plant and equipment or supporting equipment to work with, when it accounted for horizontal seismic effects, it should be included in the stiffness of the device and its supporting structure, the seismic effect effect by device or support structure and plant construction equipment lateral stiffness of proportional distribution.
Transverse structure of multilayer structure chosen accounting accounting machine accounting, when the structure of the layers of the few hand calculation method chosen, the internal forces under the effect of vertical load effects of its available approximation hierarchical method of accounting, internal force effects under the effect of horizontal load approximation method can be used semi-rigid frame method, D value method of accounting.
Accounting displacement between layers, structure - support structure may not be counted shear deformation of beam-column joints domains, web thickness of not less than beams, columns and cross-sectional height of 1/70 Hainan steel.
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