Technical Articles

Links to Technical Articles

• DESIGNERS NEED TO DO MORE THAN REFERENCE A STANDARD
• RELINING CULVERTS CAN REDUCE HYDRAULIC CAPACITY
• SHOULD SOMEONE CALL A PLUMBER?
• WHY DEFLECTION MATTERS FOR PLASTIC PIPE
• ESTIMATED MATERIAL SERVICE LIFE OF DRAINAGE PIPES
• DEFICIENT DRAINAGE SYSTEM LEADS TO DEMOLITION OF SUDBURY LIBRARY
• TRENCHING SAFETY CAN COMPROMISE PLASTIC PIPE PERFORMANCE
• CONCRETE PIPE REUSED FOR MARKDALE STORM SEWER
• CONCRETE PIPE REPLACES TWO YEAR OLD HDPE STORM SEWER
• PLANT PREQUALIFICATION PROGRAM
• ASSESSMENTS OF GRAVITY PIPE SYSTEMS
• DRAINAGE SYSTEMS UNDER THE ONTARIO BUILDING CODE
• BLACK FIBRE PIPE
• ONTARIO IS READY FOR STANDARDIZED PREBENCHED MH
• CLARIFYING HDPE STANDARDS IN CANADA

DESIGNERS NEED TO DO MORE THAN REFERENCE A STANDARD

On a regular basis the professional engineers at Ontario Concrete Pipe Association are presented with specifications for drainage systems that do little more than reference a national or provincial manufacturing standard for a particular type of pipe. Typically in Ontario, the referenced standards are developed by the Canadian Standards Association or Ontario Provincial Standards. Design engineers charged with designing our province’s infrastructure need to do more than just reference a standard. Specifically for drainage systems and sanitary sewers, designers need to recognize that successful projects demand three key elements:

•Quality pipe

•Sound engineering and design

•Proper installation and post installation inspection

RESOURCE #CPJ-015

RELINING CULVERTS CAN REDUCE HYDRAULIC CAPACITY

The following statement is made in a research paper that was presented at both the Transportation Association of Canada Annual Conference in Halifax in September 2010, and again at the Transportation Research Board Annual Meeting in Washington D.C. in January 2011.

RESOURCE #CPJ-014

SHOULD SOMEONE CALL A PLUMBER?

No one likes a drippy faucet at home, so why should a drippy pipe underground be any different? Municipalities in Ontario are paying far greater attention to the state of their sewers. The cliché,“out of sight, out of mind” is not an accepted practice anymore.

There are several reasons why a sewer pipe with a leak is not desirable.

RESOURCE #CPJ-013

WHY DEFLECTION MATTERS FOR PLASTIC PIPE

 Pipe used in sewer and culvert applications are categorized as either “rigid” such as clay or concrete, or “flexible” such as plastic, glass reinforced polymer, or corrugated steel. The common definition for a flexible pipe is: a pipe that can deflect 2% or more without cracking. While new types of flexible pipe products are continually being introduced, one critical aspect of flexible pipe design has not changed; minimize ring deflection to ensure good, long-term performance of the pipe.

RESOURCE #CPJ-012

ESTIMATED MATERIAL SERVICE LIFE OF DRAINAGE PIPES

When it comes to selecting different materials for pipe systems (i.e. sewers or culverts), the common choices are concrete, steel, and plastic. Each material has a history, and in terms of pipe applications, each carries a different track record for serviceability. "Serviceability" is defined as a period of time for which a product can service to function in its intended role. In the case of pipe systems used under our roadways, it would be the length of time that a sewer or culvert can function both as a conduit to carry water and a structure to support a roadway. 

RESOURCE #CPJ-011

DEFICIENT DRAINAGE SYSTEM LEADS TO DEMOLITION OF SUDBURY LIBRARY

The South Branch of the Greater Sudbury Public Library closed abruptly on a Friday afternoon in March 2009 due to structural concerns as a result of settlement of the foundation. A librarian turned people away at the entrance. “How long will you be closed?” the people asked. “Forever,” said the librarian. Then she locked the door. The library was built in late 1988 to early 1989. One year after the South Branch’s sudden closing, the 20-year old library building was demolished. It was gone in one day and all the rubble was carted away. A new library will be built at a cost to the City of Greater Sudbury of $4.8 million.

RESOURCE #CPJ-010

TRENCHING SAFETY CAN COMPROMISE PLASTIC PIPE PERFORMANCE

Sewer pipes not only function as a conduit to transport stormwater or wastewater, but they must also have the load-carrying capacity for whatever is built above them. One fundamental difference between a rigid pipe like concrete, versus a flexible pipe like plastic or corrugated steel; is that a concrete pipe can be reinforced to accommodate any loading condition while the flexible pipe’s structural strength is provided by the pipe-soil interaction that must be properly constructed by the pipe installer. In other words, flexible pipe is much more installation sensitive because it relies completely on the soil envelope for its structural strength.

RESOURCE #CPJ-002

CONCRETE PIPE REUSED FOR MARKDALE STORM SEWER

When specifying pipe material for pipelines and culverts, the design engineer, contractor, and eventual owner of the infrastructure system should consider the durability of that system. This is especially important within the context of designing and constructing buried infrastructure that is sustainable. Reusing products and materials is a fundamental element of sustainable development that results in infrastructure assets with long term value because of durability. Servicing of a site in Markdale, Ontario for a new Chapman’s ice cream production facility demonstrates the durability of concrete pipe, and how it contributes to sustainable development.

RESOURCE #CPJ-008

CONCRETE PIPE REPLACES TWO YEAR OLD HDPE STORM SEWER

In the fall of 2009 construction commenced on the replacement of a High Density Polyethylene (HDPE) storm sewer in a small town in South Dakota. Over 4,000 feet (1,220 metres) of 48” (1,200mm) diameter HDPE was replaced with reinforced concrete pipe (RCP). The HDPE had been installed only two years previously. The cost of the project in 2007 was $1,728,264. This project should be of interest to municipalities, consulting engineers and contractors in Ontario and across Canada as there are valuable lessons to be learned.

RESOURCE #CPJ-007

PLANT PREQUALIFICATION PROGRAM

Setting a Standard of Excellence

In a perfect world, the overwhelming number of drainage products offered today could be assessed with one set of standards.  Unfortunately, each industry has specific requirements so stakeholders of drainage infrastructure must decide if the testing and inspection of a product should be performed by a first-party, second-party or third-party.

RESOURCE #CPJ-003

ASSESSMENTS OF GRAVITY PIPE SYSTEMS

Initial Pipe Cost not the Primary Consideration

Engineers are facing budgetary challenges especially in the current recession. Designing and building infrastructure to stay within budgets becomes the primary focus and municipal and consulting engineers can lose sight of project life and service ability expectations.

RESOURCE #CPJ-001

DRAINAGE SYSTEMS UNDER THE ONTARIO BUILDING CODE

Pipe products that do not meet the Ontario Building Code (OBC) are being promoted to engineers and contractors across the province of Ontario on a regular basis.  Similarly, pipe products that do not meet the National Plumbing Code of Canada (NPC) are also being promoted across the country.  Engineers occasionally unwittingly specify products that do not meet OBC requirements. These, in turn, are installed by contractors.  Both the engineer and contractor are placing themselves in a position of risk by violating the building code.  In particular, the engineer could be subject to disciplinary action by the Professional Engineers of Ontario (PEO).  Ignorance of a code is not a defense as far as the PEO is concerned.

RESOURCE #CPJ-009

BLACK FIBRE PIPE

Are We Destined To Repeat History?

An article in the September 2010 issue of Environmental Science & Engineering Magazine (ES&E) by Dr. Mark Knight  sheds some light on a pipe material called bituminous fibre pipe, commonly referred to as black fibre pipe. This pipe is no longer produced, however many municipalities in both Canada and the U.S. are currently dealing with unexpected failures of this product. The ES&E article gives a brief history of black fibre pipe:

RESOURCE #CPJ-006

ONTARIO IS READY FOR STANDARDIZED PREBENCHED MH

Besides “manholes” being renamed “maintenance holes” in the mid 1990’s, the standards for precast concrete MH’s in Ontario have not needed to change significantly…until now.

RESOURCE #CPJ-004

CLARIFYING HDPE STANDARDS IN CANADA

Ontario Concrete Pipe Association has three professional engineers on staff with almost sixty years experience in the gravity pipe and precast industries. Throughout the course of the year we are busy interacting with design professionals and conduct Lunch and Learn presentations and seminars.

RESOURCE #CPJ-005