Landfill Grading Using

GPS Machine Control

NC SWANA

April 2018

Presented by:

Bernie Garrett, PE

Garrett & Moore Inc.

&

Gabe Leach

Cooper Barnette & Page Inc.

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Purpose

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• Work flow processes used by Engineers,

Surveyors, and Contractors to construct

landfill base grades using GPS Machine

Control Technology

Background

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• Global Positioning Systems (GPS) have

evolved in recent years to the point where

reliability and accuracy of GPS is utilized to

control construction equipment used for

grading

• CADD programs utilized by Engineers have

capabilities to efficiently develop 3-D

models of grading plans.

Software Programs

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• Engineer:– Autodesk: Civil 3D

– Bentley: Microstation

– Trimble: Terramodel

• Surveyor:– Trimble: Trimble Business Center

– Hexagon Geosystems: LEICA Geosystems

– Topcon Positioning Systems: Geo-positioning Module

– Autodesk: Civil 3D/Trimble Link

• Contractor– Trimble: Trimble Business Center

– Hexagon Geosystems: LEICA Machine Control

– Topcon Positioning Systems: Machine Control Module

Work Flow – Engineering Design

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• Permit Drawings:

– Prepared for the full build-out of a Landfill

– Approved by a Regulatory Agency

– Grading plans are lines on paper

• Construction Drawings:

– Depict a phase of landfill construction; not the entire landfill.

– Incorporate “phase” specific features, such as erosion control measures, interim anchor trench/berm, and interim access roads.

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Work Flow with Contours as Engineer’s

Grading Plan Data

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Exports Contours in .dwg format

Contours in .dwgformat

Engineer Contractor Surveyor

Contours in .dwgformat

Builds a 3-D Model in a Trimble format

Checks 3-D Model versus Engineer’s

Contours

Creates a Trimble file (.ttm)

Loads .ttm file into Operators Computer

QC/Approval of 3-D Model versus

Engineer’s Contours

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Work Flow with 3-D Model as Engineer’s

Grading Plan Data

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Creates a Trimble file (.ttm)

Checks .ttm file versus Engineer’s

Contours

Engineer Contractor Surveyor

Loads .ttm file into Operators Computer

Work Flow – Contractor

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• Coordination with Surveyor:

– Surveyor establishes and accurately measures

a network of Control Points that surround the

limits of work.

– Collected data is post processed and sent to

contractor.

Surveyed Control Points

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Site Calibration

A Base Station is installed on

the job site and calibrated

based on the data collected

from surveyor.

-Site Calibration is required to

define a relationship between

global and local coordinate

systems.

-Precision of the calibration is

crucial as it will directly relate to

the projects overall accuracy.

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Office Data Prep

• CAD Data Import

– CAD data from the design engineer is

imported and organized according to scope of

work.

– All CAD data is compared to the official

Construction Drawings.

– Once the CAD files are verified Digital Terrain

Models are built to represent the Construction

Drawings.

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3D Surface Model

-Once complete, the surface is reviewed in 3D space.

-After confirmation that the surface is error free and conforms to the

Official Construction Drawings the files are exported for use in the field.

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Field QA/QC Checks

-Dozer and Excavators are measured for blade or

bucket wear and verified accurate before and during

the project.

-Benchmarks are installed on-site and operators check

elevations on them daily before beginning work.

-Small test pad graded to a known elevation for

certifying surveyor to check. This will insure our

equipment is set up accurately and the grades we

provide will meet the certification plan.

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Machine Control

Once imported to the machines control box the operator can see

exactly where he is on the project and how much cut or fill is

required.

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Why Do We Use Machine Control?

• Gives us a technical edge over our competitors.

• Saves time and resources on the job.– Decreased stakeout work by up to 90%

– Eliminates reworked areas to meet certification grades.

• Increase productivity– Decreased material handling and material waste.

– Decreases operator fatigue.

– Increased accuracy. Grades can be met the first time accurately and efficiently.

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Grade Control Equipped Excavator

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Grade Control Equipped Dozer

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Technical Abilities Required for GPS

Manager

• High level computer skills for managing and organizing multiple file types over multiple job sites.

• Proficiency with AutoCAD software.

– Take-Offs for bids.

– Surface creation and export once job is awarded.

– Assist with material quantity updates for production studies throughout the job.

• Solid understanding of heavy construction equipment and practices.

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Technical Abilities Required for

GPS Manager

• Basic knowledge of Survey principals for

Site Calibration, Topos, and Stakeouts as

needed.

• Extensive knowledge of GPS components

installed on machines for maintenance,

repair, and operator training.

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Summary

• Landfill Owners – Be certain that your

Engineer, Surveyor, and Contractor are all

utilizing the best technology available.

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