How much more than the depth span of the building must be demonstrated by experts?

A) excavation depth of more than 5m (including 5m) of the foundation pit (groove) of earthwork excavation.

Support and dewatering projects.

2) Although the excavation depth does not exceed 5m, the geological conditions, the surrounding environment and the underground pipeline are complex, or affect the safety of adjacent buildings (structures) of the foundation pit (groove) earthwork excavation, support, and dewatering engineering.

When the building is a sloping roof building with a slope greater than 30 degrees, the building height is calculated from half of the height of the slope top to the outdoor ground level.

The height of the buildings in the cultural relics protection and construction control zone shall be according to the highest point of buildings and structures (including elevator halls, stairwells, water tank rooms, chimneys and other structures) and the traditional Chinese roof form according to the cornice.

The building height is calculated to the ground level.

The specified building height is the total height from the exterior ground level of the building to the top of the external wall. The following regulations shall be met: chimney, lightning rod.

Flagpoles, wind vanes, antennas, and other protruding structures on the roof are not included in the construction height. If the total horizontal projection area of the protruding part of the roof of a building such as a stairwell, elevator tower, decorative tower, observation tower, roof window, water tank room, etc., is less than 25% of the area of the standard floor, it shall not be included in the building height and number of floors.

'Span' is a size of beam-type members that are used for slabs, beams, roof trusses, etc. The span is the wheelbase (column distance) in the direction of 'depth', for example, on the column plane positioning diagram, the spacing between adjacent columns along the digital axis is called the frame beam.

span. Broadly speaking, the distance between the centerlines of two adjacent supports of a beam is called the span of the beam, and the same is true for the span of the roof truss. The clear distance calculated from the edge of the support is called the 'clear span'.

This question should be asked about civil engineering or learning structure, generally put the steel bar in the lower beam bearing capacity is the largest, the upper is called the frame force 6, that is to say, the above steel bar is added for the convenience of construction, so it is best to put as much steel bar as possible in the lower part, and one point is the key is the stirrup part, this is also to be calculated, there is the material of 18 walls, if it is a hollow brick, it is better, solid brick is definitely not good, and generally a beam will not carry the weight of three layers, Generally, there should be beams on each floor.

Building heights are calculated according to fire codes:

Flat roof: from the outdoor ground level to the surface line of the roof (including the insulation layer, etc.) (the chain socks in the old fire code are to the height of the parapet);

Sloped roof: count to the cornice;

There are a variety of sheds in this form of roof: take the largest of them;

Partial protrusion of the roof is not counted in the building height.