Steel roofing planning focus to note
1, steel roofing and roof purlins
Planning roof purlins and planning, now generally deploy isolation between purlins, etc., are such as roof purlins on cross-bearing, for example, over the span of just stand 15M more for gable, roof slope at each 7.5M or more. Based on the deployment of purlins, roof and other more pressing five cross beams cross in succession planning, the consequence is that many large roof-side across the span of the moment than the moment across the span, according to end-span roof span chosen moment, then in charge scattered across the roof useless play. Purlin lines for the second carriage roof mount again reaction force as the basis for the second seat cross-reaction force is gradually plate 5 biggest bearing reaction force, in order to counter-force planning purlins, this time as long as the house the second panel bearing purlins can play a role in filling casual, in a lot of cross-bearing purlins ample carrying capacity, useless filling casual play.
For this reason the use of unequal span purlins proposed deployment, roof purlins deployed at the end of the interval decrease in cross-cross at intervals across the roof to reduce the moment to make ends and two cross-survey verge moment, or because unequal purlins cross-support forces deployed to make investigations on the verge of the roof, so can charge scattered piecemeal roofing materials play function, organ deterioration amount of steel, backward cost. Piecemeal normal amount of steel roofing project total contrast large amount of steel, as well as solving effectiveness. Purlins using unequal across deployment, echoing the purlin spacing ranging from child care to deploy, purlins rod length will vary, just careful installation, is planning to meet the pleading.
2, steel roof crane beam planning
For the crane girder truss brake settings in Zhejiang province to see some light steel plant, which is within the span of 24m, and the crane is 5-20t, crane girder span between 6-8M, have all also set up a flat brake truss; Worse still have span 10M, cranes only 3t, crane girder span truss 6M also set the brake. On the basis of our planning experience, similar to hang vehicle tonnage and span not to set the brake light steel truss plant, the first is the "door frame just light the way out of Buildings and Steel Technology" (CECS102: 98) rules only light steel plant set, the light overhead crane system-level tasks, Overdose is not greater than 20t. just to meet the strength and deformation as well as pleading crane girder structure, the role of the lateral extent of the braking force to meet the crane beam lateral stability, when a surplus when the crane may be appropriate to increase the magnitude of the beam flange to ensure its stability. No brake truss crane to build and also reduces the amount of construction tasks, backward cost
3, between the steel columns support the roof plan
Support for inter-column setup, among some of the light steel plant in the column supports multi-angle scissors for each limb were simultaneous compression and tension to meet the slenderness ratio plea, therefore planning among large cross-section column support . Wall power plant light steel supporting structure for the pressure plate add more fresh information on the capitals displacement limit plant more freely wide Moreover, victorious in tonnage crane 20t, the longitudinal extent of the brake force is smaller, although again the wind load, the general area then there earthquake, located scissor scissors steel rod angle succeed, scissors steel rod, tension only accept not contemplate accept pressure. The degree of force by the longitudinal bar diameter of and planning must, but be sure to reform child pleading steel tension will really be able to convey the degree of longitudinal force. As for the set a few scissor steel rod in a structural unit, the degree of force and by the longitudinal bar diameter must, as they bring very little gas to manufacturing and construction.
4, steel roofing material choices Lord Steel
Just for light aircraft material achievements in establishing the information on the tender organs, often seen to be showing just frame is made of Q345, and high-strength materials such pleading bids more and more, that the higher authorities plan to establish the strength of the material more provincial steel, will regress project cost. This awareness has its limitations, the law is not widespread. Due to the structure of planning just frame, not just the strength of planning operations, but also just the degree of planning and operational planning firm, and trumped planning elements are relatively simple, similar to the span, bump, seismic intensity, wind load, static load, whether there cranes, crane tonnage, etc., due to higher material strength steel, the more the province, this awareness is not one-sided. Said the wind to create normal non-seismic zones contained small and large span, its member forces greater intensity grasp, high strength material will regress steel consumption, the cost will drop to create things; when high wind and seismic intensity armed load is large, often by large deformation degree just to grasp, no matter how high material strength, but also the need to maintain the rest of the member section, ability to meet the remaining degree of deformation just pleading, then high intensity contrast material cost will progress to create objects form without going to the waste.
In recent years, in some areas of Zhejiang Province, often encounter create some degree of physical planning of the earthquake of 8 degrees, and the snow load is large, the wind load is large, the span between 15-18M, grasp by just degrees, to grasp the top of the column that is deformed elements to create objects, such as advances in material strength is wrong with Q235 appropriate.
5, steel roof mount snow selection
I bought several sets of planning software company in recent years, some planning software in the output roof mount snow load on the mount output only by uniform, not wondered "Steel Mount Standard" (GBJ9-87) in the roof of snow distribution coefficient, single-span gable roof often encountered and double cross-gable roof, as well as up and down across the adjacent roof, do not contemplate snow load uneven distribution coefficient, to bring a small convenience when planning can be formed without insurance . Especially in the Xinjiang region bitter cold, snow load is large, is secondary to grasp the structure of the roof mount, some planners think is a program intended simply no score, it also has some procedural imperfections, to the bitter cold at the regional planning note uneven roof snow factor, especially in the upper and lower cross adjacent to create some things, even if the program does not contemplate the snow load symmetry factor, it should mobilize themselves to ensure that the structure of insurance.
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