What is the meaning of two-step and three-span scaffolding, and how to place Rachel pieces for drawing?

Two steps and three spans are the layout rules of fastener-type steel pipe scaffold wall-connected parts.

Two steps is the height of two steps. Three spans, that is, the distance of three spans of the crossbar. One step up and down, one step across.

As shown below: A to B is two steps, B to C is three spans, and ABCD point is the layout of the wall part.

Scaffolding should be set up outside the house. Then when the house is built to a certain height, ten or twenty stories, or even higher, the scaffolding will be in danger of falling down.

Wall-connected parts are components that strengthen the stability of other structures through reliable fixed-end connections. They are used to connect the scaffolding frame with the wall structure of the main building in building engineering, and play an important role in improving its stable bearing capacity and avoiding dumping or collapse.

Then its connection must have its certain regularity, which is called "two steps and three spans"

The concrete layout diagram of Rachel reinforcement is as follows:

Extended data:

What are the basic parameters of scaffolding? : ?

(1) Material requirements for steel pipes: the steel pipes shall be Q235 ordinary steel pipes specified in national standards GB/T 13793 or GB/T309 1, and the model shall be φ 48.3 &; Times; 3.6mm (scheme according to φ 48&; Times; 3.0mm calculation), material approach should provide product certificate and acceptance, qualified rear can put into use.

(2) When the fastener comes into play, the product certificate shall be checked and the second interview shall be conducted by sampling. The technical performance shall conform to the national standard "steel tube scaffold couplers", and there shall be no cracks in the appearance inspection of fasteners. When the bolt tightening torque reaches 65N &；; Middotm, no damage is allowed.

(3) Outside the frame, the steel pipe of the hand frame must be derusted. After derusting, brush one coat of antirust paint and two coats of topcoat.

(4) Wooden scaffolding model 3000 (6000)&; Times; 200(250) pounds & era; 50, both ends are bound with φ 1.6mm galvanized iron wire; Steel wire mesh scaffolding adopts hpb 235φ6 steel bars with a spacing of 40mm, and is fixed on the small bar with φ 1.6mm galvanized iron wire.

References:

Baidu Encyclopedia-Scaffolding Construction Scheme