How can we make duct bank show in the attached image.
The example image contains what appear to be many telecom and electric ducts. To model this in AUD you need to create 3D Model and Detail blocks for corresponding Segment and structure models. The blocks should be defined with ports defining the offsets/locations of each duct.
To create instances of the model you will need to setup Feature Library or CUI macros which allow the entire collection of ducts (and contained conductors and cables) to be drawn at once, or to use other commands such as AUDADDTOSEGMENT to add them individually to the same segment in the design.
There should be some examples and details concerning configuration of this in the whitepaper entitled "Detail and 3D Model Creation for Trench and Structures". The whitepapers are accessible on Subscription Center.