Sewer Collector Mains Design - Canterbury - Eliot Sinclair and Partners

ClientEliot Sinclair and PartnersLocationNew Zealand
ConsultantEliot Sinclair & PartnersContractorSam Cech

Sewer Collector Mains Design


Project Summary

Sewer Collector sub-main design and drafting.

The Challenge

The 2012 earthquakes in Canterbury highlighted the high cost of repairing deep property connections. The Christchurch City design standards were updated as a result of this disaster, to allow for construction of collector sewer sub-mains for property connections. When these collector pipes are located within the same trench directly above the main pipe, difficulties arise in DNE and PPF options within 12d Model. It is possible using existing DNE tools to design the sub-main and main DNE networks separately and plot individual XS for each pipe. However, this causes issues with the construction when contractors want to see all the information about that trench on one section. City design officers checking these plans want to see pipes and their grades, inverts types, etc. on one plan for ease of checking. It is also the requirement by the local city council and their Design Standards.

Therefore, it was necessary for the team to create an innovative way around this challenge. There are two parts to this:
Design – creation of 3D strings with pipe diameter, type and properties
Drafting LS plots and combine Sewer main and sub-main pipes and information.
The client had an added difficulty with designing a process that can be quickly and easily implemented with large number of users working on earthquake recovery works.


The Solution

The team created a 12d Model macro that allows users to add a secondary pipe to a DNE network pipe, draws a superstring for visualisation and drafting purposes, and stores design information as attributes on the DNE drainage string. Within the PPF editor, they used these attributes to label information about the sub-main, showing them in the same boxes as the main pipe.

Design settings were available for users to automatically calculate inverts for the sub-main, either by clearance to main pipe or depth from ground TIN.

The Result

The team’s Clip-On sub-main macro and PPF files achieved all the requirements by the client and consenting authority. Their innovative use of 12d Model gave them the results they needed for this important project.

Download this Case Study as a PDF HERE