#CULVERT DESIGN SPREADSHEET PRO#

Note that you cannot apply a moving load directly on plate elements on Staad Pro, but you will need to create dummy beam members of negligible stiffness so that the axles can sit on them. The ideal thing is to apply a moving load on Staad after vehicle definition, such that the worst effect can be obtained. As a reminder, the nature of Load Model 1 (which can be used for global and local verification) on the culvert is given in Fig 14 below When there is no earth fill on the box culvert, all we have to do is to remove the vertical earth fill load, apply direct traffic load on the top slab, and edit the horizontal earth load from trapezoidal to rectangular.

Therefore, provision of c/c (A sprov = 2010 mm 2) on each face will be adequate.Дesign Case B: No Earth Fill on Box Culvert When designed, the area of steel for the axial compression and bending is 1223 mm 2/m. (5) Horizontal earth pressure load = trapezoidal distribution with minimum earth pressure of 11.40 kN/m 2В at the top of the culvert and 33.25 kN/m 2В at the bottom of the culvertДЇig 12: M-N Interaction Chart on the Box Culvert (4) Horizontal surcharge load = 5.0 kN/m 2 (3) Traffic load dispersed as UDL = 59.523 kN/m 2 (2) Vertical earth load on the culvert = 22.80 kN/m 2 NB: In some cases, the partial factor of safety for self weight of concrete elements and other superimposed dead loads like asphalt wearing course might be different, so in that case, it is very advisable to treat each of them as a separate load case on Staad. (1) Self weight: To be calculated automatically by Staad + 1.69 kN/m 2 (self weight of asphalt wearing course) In our previous post, we were able to analyse the loads on the culvert for Case A as follows We have determined the magnitude of these loads in our previous post, and we are going to apply them on the box culvert for Case A and Case B. Please note that effects of ground water and the pressure in the shell of the culvert when it is filled with water is an important load case too but was not considered in this post. These load cases are considered independently at first, and then combined with appropriate partial factors of safety to determine the design actions. (1) Self weight and other superimposed actions However, to incorporate the effects of soil-structure interaction (to a limited degree though) on our model, we can employ the use of вЂ elastic plateвЂ foundation option on our model. There are many proposals on how culverts can be modelled as 2D frames, and the reader is advised to consult as many publications as possible.

A purely rigid approach will involve using fixed supports, but note that employing 3D model for this purpose will not be very appropriate, but a simple 2D frame model will be better. This is an important aspect of modelling structures. (2) Assigning of support conditions/foundations The meshing process can be completed by adding plate thickness of 300 mm to all the elements. The final output of the meshing operation is as shown below The output of this operation is as given below ДЇig 2: Initial Nodes for Commencement of ModellingДЄfter forming this, the wing walls can also be formed, which is followed by meshing (rectangular or polygonal) to form the shell of the box culvert. This can be started by forming the nodes in the global XY plane, and then copying and pasting for the length of 8 m in the Z global direction.

#CULVERT DESIGN SPREADSHEET PRO#

This means that the width of the box culvert that will be input into Staad Pro is 2.5 m, while the depth will be 2.0 m. Here, the box culvert is idealised with dimensions based on centre to centre of the slabs and walls.

The steps in modelling the structure on Staad Pro are as follows

Culvert design spreadsheet