Grading and Excavation Contractor

By Andrea Estrada

Introduction
Some call it the biggest change in land development since the Industrial Revolution. They’re talking about the technology boom that is transforming the way design engineers, contractors, and job-site crews tackle their grading and excavation jobs. What used to be done manually can now be completed more efficiently and accurately with, say, a laser or global positioning system (GPS). Machine control systems like these and others bring a precision to the work site that contractors and equipment operators couldn’t fathom 10 years ago. No more waiting for a layout or grade staking to indicate how much dirt needs to be moved in a work area, and no more rolling repeatedly over a test strip to determine how many passes are necessary to attain the requisite compaction. Gone are the days of measurements taken by hand and operators relying on their judgment and experience to grade an area.

Likewise, equipment systems have taken a giant leap forward in recent years with electronically controlled fuel injection systems taking the place of carburetors, for example, and hydraulic valves operating by way of changes in electric current rather than a pushrod. And that’s just the beginning. The dozers of the future will resemble their predecessors about as much as a Ferrari does a Model A Ford.

Grading & Excavation Contractor is joining this 21st century construction revolution with a new regular section called Technology in Construction that will introduce, highlight, and examine the new technologies and systems. In these pages you’ll read about everything from equipment controls and systems that alter the way a backhoe or skip/load operator moves his machine to a host of software programs that help a contractor organize and manage all aspects of his business.

You’ll meet professionals in the field who share their experiences with the new technologies, explaining how they’ve incorporated them into their projects and how they’ve increased their productivity and improved their bottom lines. In the process, you’ll get ideas about how the new technology can help you improve and even expand your own business.

“We’re living history,” Topcon’s Richard Rybka says of the technology evolution. “You see people using it across the country from the Pacific Northwest to New England. It’s a massive progressive change.”

From lasers to construction management software, technology is creating a whole new world within the construction industry. New job opportunities are emerging for people ready catch this wave of the future. GPS specialists, for example, are finding themselves in high demand, as is the crew member who is well versed in data management, field operations, and how machinery works.

“It’s not only changing the way contractors do business but their responsibilities on the job site,” Rybka says of the technology that provides accurate, up-to-the-minute information that gives contractors a professional edge. “It’s really changing the contractor’s position on the ladder.”

There’s no doubt technology will continue to march forward and the construction professionals who take advantage of it will lead the industry. By featuring state-of-the-art machine controls, software programs, equipment systems, and more, Technology in Construction will help you stay at the head of the pack.

Machine Control
In the last few years a major change has swept over the world of construction equipment, and it can be summed up in two words: machine control. Machine control can take practically all of the guesswork out of grading and excavation by using laser, global positioning, and other advanced technology to set parameters and measurements otherwise done manually or with a trained eye.

Truly the wave of the future, machine control means as much to construction work now as the tractor did to farming almost 100 years ago.

Machine control consists mainly of laser and global positioning systems (GPS), machine interface systems, controls, and displays. To help acquaint readers with the technology that nearly all will encounter over the course of their professional lives, Technology in Construction will introduce the components, highlight their uses, and show how they come together in one piece of equipment. Descriptions and explanations will help readers build a basic understanding of how the elements work and how readers can incorporate them in their own construction jobs.

The goal of a grading and excavation job is to work a construction site with the appropriate equipment to achieve a design created by an engineer. Even if the job is a flat building pad, it usually has some slope. That slope can be created more efficiently and accurately than ever with the new technology. It might be a laser control system that provides two-dimensional control; it could be a robotic total station used for measuring angles and distances. Each of these, along with global positioning systems, calculate precise measurements and relay them to a display inside the cab.

Machine control systems fall into two categories: indicate and automatic. With an indicate system, the operator knows how to achieve the grade specified in the design requirements for his particular area by tracking information that appears on a display inside the cab. Indicate systems provide the operator with visual guidance so he can place the cutting edge or bucket properly, but he maintains control of the equipment. With an automatic system, the operator drives the machine, but the various systems—laser, GPS, etc.—control the movement of the blade or the bucket to achieve the same result. The operator doesn’t have to do anything but keep the machine moving in the right direction. The automatic system places the cutting edge appropriately on the design surface, and the machine does the rest.

An indicate system still requires the operator to know where to fill, where to cut, and where to deposit dirt, but the automatic system allows him to achieve his specified grade more precisely and efficiently.

Machine control has revolutionized the construction industry by making it possible for jobs to be completed more quickly and with the highest degree of accuracy. With wireless technology, a contractor can match a design engineer’s specifications to within one-tenth of a foot. Also, the technology lets him work in real time so design changes can be made or incorporated into the job site in practically an instant. With a wireless computer in the cab of his pickup truck, a contractor can receive up-to-the-minute progress reports from his equipment, download design changes sent by the engineer, and blend the two seamlessly by programming the new design specs into, say, the GPS-controlled hydraulic system.

Machine control systems operate through microprocessors situated deep within the equipment, which monitor every aspect of a machine, including operating information such as engine temperature, fuel, and oil use. They also control the critical hydraulic system that allows a blade or bucket to move with ease and accuracy.

Whatever the job site, every project begins with plumb, level, and square reference points from which the rest of the construction grows. A laser is the tool of choice for bright, crisp two-dimensional reference points or for an accurate plumb layout. Contractors can choose from carpenter levels, laser levels, rotary levels, and hybrid laser products.

For the person who installs acoustic ceilings or cement flatwork, for example, a rotating laser with a detector is necessary. Rotating lasers provide a continuous plane, either vertical or horizontal.

Some lasers are ideally suited for large job sites and agricultural land leveling and feature an integrated radio remote controller capable of two-way communication up to 1,000 feet. Radio communications between the remote and the base laser allow the operator to verify adjustments right from the cab of a machine.

Still others provide complete visual grade control with up to nine channels of information and three on-grade positions. The operator can tell at a glance how much grade he needs to cut, which makes grade control a one-person job. The grade checker can turn his attention elsewhere.

A laser also can provide three-dimensional positioning information by way of a machine control system. A fan-beam laser communicates digital control data to a receiver attached to the machine. The receiver takes in elevation, design cross-slope, and steering information, which it sends on to the control box.

Another system looks to the sky for information about location, position, and direction. GPS is a worldwide radio-navigation system formed from a constellation of 24 satellites and their ground stations. This particular constellation was launched and is operated by the United States. Other constellations are orbiting some 11,000 miles up in space, including GLONASS, operated by Russia, and Galileo, launched by the European Space Agency.

Global positioning allows construction engineers to take information broadcast by the satellites and use it to calculate the required position of equipment and survey lines to achieve accuracy to within one-tenth of a foot. Some operate in collaboration with laser systems for even greater precision. On the job site, GPS receivers are attached to machines, which pass data to an onboard computer that holds digitized site information. In real time, the information is broadcast from the satellite constellation to the receiver and on to the computer to guide the equipment’s movements. In an indicate system, the data appear on a monitor inside the cab, and the operator uses the data to guide the machine. With an automatic system, the computer directs the movements of the machine, such as controlling its hydraulics and raising or lowering a blade or bucket automatically.

Often a contractor will use an indicate system for the bulk of an earthmoving job and an automatic system for the fine grading.

With advances in machine control and the subsequent development of machine interface systems that keep a bulldozer and other construction equipment on the job, construction workers find themselves scaling a learning curve to become proficient in the new technologies. Clutch-and-brake and cable-control have given way to hydraulic systems that detect the slightest motion of a joystick and respond accordingly. It’s a new world for contractors and operators, and those who resist the new technology will likely find themselves left in the dust.

Equipment Systems
Exploring the various equipment systems that make backhoes, excavators, skip/loaders, and other construction beasts move with agility and relative ease, Grading & Excavation Contractor’s new Technology in Construction section will take a look at the new technology that is changing the way construction equipment works and operators do their jobs. The key components are hydraulics, mechanical systems, electrical systems, controls and instrumentation, power plants, transmissions, and components and accessories. In this first issue we offer an overview of each component and how together they make for a powerful piece of equipment. In subsequent issues we’ll examine each component separately and in greater detail.

Much has changed in the world of equipment systems, not the least of which is hydraulics. Hydraulic pressure gives construction equipment much of its power by making it possible for the individual components of a piece of construction equipment to move. A hydraulic system consists of hydraulic lines, a reservoir of hydraulic fluid, a pump, and a series of pistons. In the new hydraulic technology, electric current rather than a pushrod causes valves to open and close.

Mechanical systems also have undergone changes in recent years. Steering wheels, pedals, and levers are being eliminated in favor of joysticks that allow the operator to keep his hands on more than one control. With one stick he can move the backhoe forward or backward, and with the other he can control the dig of the bucket.

Similarly, advances in hydrostatic transmissions allow the operator to choose the appropriate travel speed for the job and enable him to shift back and forth from forward to reverse without using the clutch or brake. In the past, an operator had to pay attention to a host of factors while getting his grading or excavation job done. Now an on-board computer handles much of that. When the computer detects an unbalanced load on the blade, for instance, it makes the appropriate adjustment automatically.

With electrical systems, the significant change is the controller area network (CAN) serial bus, which serves as a communication system for the machine. With the new technology, electrical systems are more interrelated with the operation of the machine as a whole. With the CAN bus, for example, variations in current cause valves to open and close rather than the operator flipping a lever and doing it manually. A special feature of the CAN bus is that components can be plugged in modularly and don’t impact any existing wiring.

As technology has moved forward, so have instrumentation and control. The on-board computer allows for a continuous stream of information, all of which appears on a digital monitor system. The operator has quick access to the machine’s performance history and diagnostics, and for those machines equipped with after-market global positioning systems, the monitor system allows him to switch back and forth between machine function data and global positioning system (GPS) information.

While GPS is a popular addition to a machine’s standard features, a plethora of aftermarket components, accessories, and systems has been developed that allow machine operators to use their equipment in different ways. An excavator, for example, can become a rock cutter when the bucket is replaced by a hydraulic rock hammer.

The past two years have seen some tremendous changes in construction equipment and operation. In the old days, a backhoe ran pretty simply. A carburetor, generator, and battery and a fairly simple system of hydraulic valves kept it going. The operator controlled it with levers and did everything by eye because all the components functioned manually. Speed and accuracy depended on his skill. Not so today when equipment manufacturers follow a never-ending quest to improve the performance of their machines and outfit them with user-friendly controls that make grading and excavation work more science than art.

Software for Contractors
With the right software applications and systems, a contractor can keep track of every aspect of his business from managing his payroll to tracking maintenance and repair on his bulldozer.
Within their categories, the various software programs differ from one another in a few respects such as window design and individual features. A general overview of current software follows, and in subsequent issues Technology in Construction will take a closer look at individual applications and explore how professionals have applied them to their businesses.

Construction and project management software such as Smart Contractor allow a user to control practically all the administrative tasks associated with his business. Fully integrated with Quickbooks, the software can create job estimates; generate custom job proposals and contracts; create job activity schedules complete with employees and subcontractors; generate requests to vendors and subcontractors; create purchase orders; track change orders and allowance variances; print invoices or bank draw requests; track payment receipts and other accounts receivable; track job costs; print job recap reports and make final payment calculations; create a variety of cash flow reports; track customer contacts; and even store job-site photos.

With its Quickbooks integration, this type of software also allows a contractor to manage financial and accounting issues such as accounts payable and everything related to payroll.

Fleet management software enables a business owner to maintain complete records on all his equipment. The software generates reports that cover a range of topics including vehicle costs; a parts inventory; fueling; tire management; mechanical productivity; purchasing information; vendor information; driver interface and reporting; depreciation; and asset tracking.

Equipment and inventory management software such as that offered by Cheetah allows contractors to know at all times where their equipment is located and how it is being used. It also enables contractors to maintain service records, create repair and maintenance work orders, and even track warranties.

In addition to software applications specializing in construction business management, a variety of specialty software systems cover areas such as human resource management; education and training; civil engineering and surveying systems; computer-aided design (CAD); and geographical information systems and mapping.

Human resources software automates the process of employee management so contractors can tailor employee record-keeping to fit their needs. With the software they can track employment history, status changes such as pay rates or tax changes, 401(k) administration and eligibility, health benefit eligibility, and more.

Other innovative software applications assist with fieldwork by calculating cuts and fills, stripping, strata quantities, subgrade materials, topsoil re-spread, areas, lengths, trench excavation, and backfill from digitizer input or CAD import. These applications can automatically list the fill required under each subgrade as well as any subgrade material; calculate the water, storm, and sanitary sewer excavation by strata; and backfill quantities from traced profiles or from contours. They can assist with highway construction, site development, and general earthmoving projects. Special features of these include a built-on AutoCAD engine; digitizing, drillhole, trenching, and roads routines; calculating volumes and material quantities; cutting and filling color maps and labels; creating three-dimensional drive-over simulation; preparing files for stackout and machine control; and two-dimensional to three-dimensional conversion routines for linework and spot elevations.

GEC - July/August 2006

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