Bidirectional bending
16
The short sides of unequal angle steel are connected? Short side down.
150 350
L2/250 L2/300
Both spindles are equally stable.
9-36 6- 12 4.5-9
Angle between adjacent steel bars, bolt diameter and length of bolt extending into sphere.
Second, short answer questions
1. Answer: The limit of lateral displacement of the column top of portal frame is not greater than 1/60 of the column height. If it is not satisfied, one of the following measures can be taken: (1) Enlarge the column or beam section; (2) The hinged column foot is changed into a rigid column foot; (3) The single rocking column in the multi-span rigid frame is changed to be connected with the upper end beam.
2. Answer: The rigid connection between inclined beam and inclined column of portal frame generally adopts high-strength bolt-end plate connection. Concrete structures include vertical end plates, inclined end plates and flat end plates. The thickness t of the end plate can be calculated according to the supporting conditions, but it should not be less than 16mm, and the flange part of the column connected with the beam end plate should be the same as the thickness of the end plate.
3. Answer: When the slope of the inclined beam does not exceed 1: 5, the strength of the flexural member and the out-of-plane stability of the rigid frame are calculated, but the in-plane stability is not calculated. Out-of-plane calculated length of solid web rigid frame inclined beam is used as the spacing of lateral support points. When the distance between the lateral support points of the two wings of the inclined beam is not equal, the distance between the lateral support points of the maximum compression flange should be taken. There is no need to calculate the maximum length between the lateral support points of the overall stability of the inclined beam, and the width of the lower flange of the inclined beam can be taken as yf/235 16 times.
5. Answer: The profiled roof steel plates can be connected laterally in different ways, such as lap, buckle and bite. When the overlapping type is adopted, one wave usually overlaps, and two waves can overlap when special requirements are required. The lap joint is fastened with connectors, which should be set on the wave crest, and the connectors should be self-tapping bolts with waterproof sealing rubber pads. High-wave profiled steel plate, the distance between connectors is generally 700-800 mm; For low-corrugated profiled steel plates, the spacing of connectors is generally 300-400 mm When buckles or buckles are used, special fixed supports matching the corrugated shape of profiled steel plates should be set on purlins. The fixed support is connected with the purlin through self-tapping bolts or nails, and the profiled steel plate is placed on the fixed support. The side edges of two profiled steel plates shall ensure reliable fastening or bite connection.