Course Sponsor:

Jay R. Smith Mfg. Co.

2781 Gunter Park Dr. E

Montgomery, AL

36109

Ph: 334-277-8520

Fax: 334-272-7396

Salesengineering@jrsmith

.com

www.jrsmith.com

Trench Drainage Systems: Types, Benefits, Applications

and Overview

Outline

Background, operation and design of trench drain system.

Design advantages of trench drain system.

2

Learning Objectives

At the conclusion of this course, you will be able to: 1. Describe the basic ideas of trench drainage system.

2. List the benefits of trench drainage systems.

3. Compare and contrast the differences between traditional trench drainage systems.

4. Cite case studies and installation examples of trench drain systems.

5. Describe how trench drainage systems can help reduce project costs.

3

Trench Drainage

Drainage is the process of carrying water AWAY from a specific place.

The process of drainage has been around for many years. Trench drainage (floor trench) can be referred to as: channel

drainage, line drainage, trip drainage and slot drainage. Trench drains are considered to be an open trench with

removable grates. Slot drains are a slot in the pavement connected to underground drains and to not have removable grates.

Generally a trench is regarded as the completed job in the ground. A channel is an individual modular piece which when added to others makes up the drainage system.

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Reasons for Surface Drainage

Reduce Ponding

Reduce Slip Hazards

Protect and Extend Life of Paved Surfaces

Protect Property from Flood Damage

Reduce Inconvenience to Public Users

Reduce Hydroplaning Hazard to Vehicles on Roads

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Options for Handling Surface Drainage

Ignore It

Open Swale

Catch Basins

Trench Drains

6

Open Swale

Trench Drains

Catch Basin

Types of Drainage

Catch Basin Drainage

Modular Trench Drainage Systems

Cast in Place Trench Drains

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Disadvantages of Catch Basin Drainage

Uneven appearance. Complex, multiple grades to design and construct. Deeper excavation required due to pipe depths. Higher risk of ponding. Pipes prone to blockage and failure. Maintenance can be difficult and costly since piping is not

accessible. Possible interference with other utilities, i.e. electrical,

sewage, etc.

8

Disadvantages of Cast in Place Trench Drains

High labor cost.

Time consuming due to on-site formwork.

Hand-formed poured-in-place concrete trenches often are not uniform in the slope.

Concrete absorbs water.

Difficult to get a uniform slope.

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Disadvantages of Cast in Place Trench Drains (cont.)

Slower drainage due to wide trenches

Debris and standing water result from slower flow and create unsanitary conditions

Concrete is attacked my mild acids, caustics and saltwater

Concrete patching is difficult and time consuming

Grates often have to be ground or otherwise modified to fit and to keep from rocking

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Trench Drainage

Neat, linear appearance Simpler grades to design and construct Easier to install due to shallower

excavation and pre-sloped sections make it easier to construct since slope is built in

Continuously intercepts water and provides superior drainage

Minimal underground piping Maintenance is quicker and easier since

trench is at surface Less interference with other utilities since

excavation is shallow

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Possible Uses for Modular Trench Drainage Systems

Food Processing Facilities Animal Facilities Stadiums and Sporting Facilities Fire Stations Vehicle Maintenance Facilities Pools Airports Manufacturing Plants Lawn and Garden Centers Retail Stores Parking Lots

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Benefits of Precast, Modular Trench Drains cont.

Rapid drainage. The drain bottom is shaped to increase velocity during low flow conditions and helps in self cleaning.

Closed cell structure of polymers and negligible water absorption prevents collection of bacteria and stops gasoline and other pollutants from getting into the soil.

Highly chemical resistant. Not eroded by cleaning agents in wash-down water in food processing plants.

Easily maintained since smooth, radius channels don’t collect debris.

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Application Factors in Modular Trench Drainage System Selection

Hydraulic Performance – the amount of liquid to be intercepted, collected and carried in a specific time period Traffic type and frequency Wheel size and type Static versus dynamic loading

Loading – what loads will the trench be subjected to Traffic type and frequency Wheel size and type Static versus dynamic loading

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Application Factors in Modular Trench Drainage System Selection cont.

Durability– how the trench system performs over time Material choices and performance Chemical resistance Installation

User Requirements – project specific options Aesthetic – visual look requirements Safety – ADA (Americans with Disabilities Act) requirements,

pedestrian requirements – ladies heels, slip resistant finish, etc.

Security – ease of removal of grate

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Sizing a Modular Trench Drainage System Example – Step 1

For an application that has 2” per hour of rainfall with a trench drain located across a paved area. The lot is level along the 130’ length and slopes to the center of the 65’ dimension. Existing conditions allow the outlet anywhere.

Step 1. Determine the total volume flow rate. 130’ x 65’ = 8450 Sq. Ft. 2” per hour / 12” per foot = 0.167’ per hour 0.167’ per hour X 8450 Sq. Ft. = 1411 CFH (Cubic Feet per Hour) 1411 CFH / 3600 Seconds per Hour = 0.39 CFS (Cubic Feet per Second)

0.39 CFS – Convert to GPM (Gallons per Minute) = .39 * 7.48 * 60 = 175 GPM 175 GPM is the total volume flow rate required for the catchment area.

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65’

130’

Step 2. Decide on correct layout. Since the trench exceeds 100 feet in length and we would rather not use extension walls, the catch basin will be placed in the center and slope each end to the catch basin.

65’ 65’

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Sizing a Modular Trench Drainage System Example – Step 2

Application and Uses for Modular Trench Drainage Systems

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Extra Heavy Duty - • For use: Commercial solid tire traffic patterns, forklifts, and

impacts from steel struts or metal wheels.

Heavy Duty - • For use: Commercial pneumatic tire traffic patterns,

forklifts, and tractor trailers

Medium Duty – • For use: Passenger cars and vans

Light Duty - • For use: Pedestrian, wheel chair and bicycle traffic areas.

Cast Iron Trench Drains

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Features and Benefits

Applications

• 1’ long non-sloping channels.• Channel sections are bolted together.• Channel sections available with flashing flange and

flashing clamp.• Channel sections can be provided with acid

resistant coating when specified.• Channel sections are appropriate for high

temperature applications.• Channel section grates can be provided with vandal

proof screws when specified.• Channel sections can be provided with caulk,

threaded or no-hub outlets.

• Truck Loading Docks• Parking Decks• Above Grade Applications

Precast Modular Trench Drains

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Features and Benefits

Applications

• Lower installation cost; no formwork required.• Smooth interior finish for complete drainage.• Less than 1% water absorption per ASTM C-97 for high freeze/thaw resistance.• Slope is built into channels.• No grouting trowelling.• Rapid drainage. The bottom is shaped to increase velocity during low flow conditions and helps in self cleaning.• Closed cell structure of polymers and negligible water absorption prevents

collection of bacteria and stops gasoline and other pollutants from getting into the soil.

• Highly chemical resistant. Not eroded by cleaning agents in wash-down water in food processing plants.

• Easily maintained since smooth, radius channels don’t collect debris.

• Food Processing Plants

Fiberglass Trench Drains

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Features and Benefits

Applications

• Channel sections are available in 3’, 9’, and 9’ 10” long.• Multiple frame material available, powder coated steel,

stainless steel and galvanized steel.• Channels are available in neutral (flat) and 1/8” sloped.• Channel depths range from 6 3/8” to 20 3/8” deep.• High flow bar grates available in galvanized steel and

stainless steel material.• Fiberglass channels are available in two different resins,

polyester and more chemical resistant vinylester.• 4”, 6”, or 8” vertical or horizontal outlets are available.

• Airport Hangers• Water Treatment Plants• Parking Lots

Polymer Concrete Trench Drains

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Features and Benefits

Applications

• Available in two neutral depths and 20 interlocking, 0.6% pre-sloped channels.

• The shallowest channel is 13.06” and the deepest channel is 17.81”.

• Closing end caps and horizontal outlet caps provide for a complete drainage system.

• Strengthening ribs on the channel sides create a stronger and safer system capable of withstanding the considerable loading imposed by the turning action of heavy wheeled vehicles.

• Side profiling also provides anchoring to the surrounding concrete to prevent movement due to freeze-thaw cycles.

• Airports• Warehouses• Bus Depots

• Service Stations• Military Bases• Highways

Modular Stainless Steel Trench Drains

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Features and Benefits• 1 Meter Channel Sections, 39.38” long and 6.38” wide.• 4” Wide Throat with Bolting End Plates.• 23 Modular Chanel Sections Made of 16 Gauge, type 304

Stainless Steel.• 4 Neutral (flat) Channels and 15 Channels with .6% Build-

in Slope.• Channel Inverts Range from 3.75” to 7.50”.• Regularly Furnished with Secure Light Duty Slotted

Stainless Steel Grate.• 4” No-Hub Vertical Outlet on Channel Sections 2,5,10 and

15.• End Outlet Plates Available in 2”, 3”, and 4” No-Hub.• Available with Flashing Flange and Flashing Collar.• A variety of Stainless Steel Grates Available.

Applications• Bottling Plants• Commercial Plants• Food Handling (Restaurants and Cafeterias)

Case Studies

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Lincoln Center Performing ArtsNew York, NY

The Lincoln Center Performing Arts project was a renovation and required that existing load structures had to remain intact. Most of the project called for irregular or custom designed trench drains. An engineered stainless steel trench drain system was provided for the project.

Case Studies

25

Trench Drains at University of Cincinnati

The UC Trabert-Talbert Tennis Center consists of a six-court tennis complex with a central grandstand and was constructed over a 150-car underground parking garage. Due to the tennis courts being located above the parking garage, a trench drain with flashing was required to prevent any water leaks into the parking garage. A membrane drain with waterproofing clamping system was provided for the project.

Case Studies

26

Automotive Service Center

A fortune 250 company built a large scale, high end luxury automobile showroom in central New Jersey. They requested a solution that could be designed and installed without delays and with minimal disruptions. A high capacity pre-sloped fiberglass trench drain system was provided for the project.

Course Summary

By now you should be able to:

Describe the basic ideas of Trench Drains

List the benefits of Trench Drains

Compare and contrast the differences between traditional drainage and engineered trench drains

Cite case studies and installation examples where a trench drain systems benefited the owner

Describe how a trench drain system can help reduce project costs

27

Course Sponsor:

Jay R. Smith Mfg. Co.

2781 Gunter Park Dr. E

Montgomery, AL

36109

Ph: 334-277-8520

Fax: 334-272-7396

Salesengineering@jrsmith

.com

www.jrsmith.com

Trench Drainage Systems: Types, Benefits, Applications

and Overview