3D grade control allows crews to achieve a slope of 0.01% more efficiently
Turkey is no doubt a country with a vibrant and influential history. This is the area of the world where Alexander the Great once ruled and where battles were fought by the Trojans in Homer's Iliad. Today, Turkey is still ripe with energy and is a central figure with an influence around the world. Modern day Turkey covers a .75 million square meter area with a population of 75 million.
Continuing to build onto its modern infrastructure, the State Water Works authority of Turkey is responsible for building and updating dams, irrigation channels, and man-made lakes. Recently the authority embarked on a project to construct an irrigation channel that will be divided into three parts, covering a total area of 63km. This main channel will run water from one of the largest dams in world to a manmade reservoir. Spanning a total area of 211,375 hectares, the resulting waterway will provide irrigation for the entire south eastern region of Turkey, which is known as low land Mesopotamia. The channel and reservoir project will support large-scale agricultural production across the entire region.
Adding to the challenges of the project is the remote location and geologic composition of the land. Most of the area is covered by volcanic basalt and limestone that must be blasted, crushed, and removed. The crushed basalt will then be screened for use as concrete aggregate. In total, the company was tasked with moving approximately 17,000,000 cubic meters of earth. Plan specifications dictate that there is no layered material between the poured concrete and the soil, except geotextile. This means, the entire project area must be graded with extreme precision in order to reach a total slope of 0.01 percent. To achieve this slope, multiple professional surveyors and grade checkers are required. These surveyors must continuously monitor the progress of these cut and fill efforts and communicate with the other grade checkers, and excavator, grader and dozer operators.
"The continuous grade checking efforts were slowing down the paving work to a point where it took five people and one excavator to reach final grade," said Ömer Alpora, manager with Graftek, a Trimble dealer and GPS and survey software specialist. "Plus with extremely high fuel costs, it wasn't surprising that after a year into the project it was losing money every month."
Faced with these challenges and the large project scope, the State Water Works authority commissioned work with several civil engineering companies, including Eren Construction. Eren construction has a 30-year track record of successful engineering and construction projects; the company was founded by Mr.Yasar Eren, president of Eren Construction.
Eren Construction and invested in more than 100 new heavy highway machines, from excavators to motograders. Looking to also use technology to speed production and lower operating costs, the company worked with local survey equipment experts and specialists in mapping, GPS and survey software. Alporal from Graftek as well as Reha Imer, manager with SITECH® Eurasia, the Trimble Heavy and Highway dealer in Turkey, collaborated to deliver a complete machine control system for this irrigation project. Eren Construction selected the Trimble® GCS900 3D Grade Control System.
The first test of the Trimble system was on a large excavator. The GSC900 system essentially uses GPS, GPS and laser, or total station technology to place the grade and alignments inside the cab for the operator to see directly. Within the first five minutes on the job site, the operator was using the Trimble Grade Control System, helping to ease concerns regarding the training and adoption of the new technology by the crew. The machine chiefs and supervisors alike were impressed by the system's ability to guide the operator to precisely position the blade or bucket in real time. By accelerating the mass excavation with work the GSC900 solution, the team was able to reach near-final grade slope much more quickly. They then used smaller machines to finish the fine grade process.
"With Trimble, the project owner saw a 100 percent increase in productivity immediately because machine control enables the jobsite to continue production work 24 hours a day, instead of only during daylight hours," said Alporal. "And because the machines are used like survey equipment they deliver extreme accuracy as well as increased efficiency."
After just three weeks of using the system on a single excavator, the team was able to finish 4.5km of the irrigation channel. Pleased with the performance of the GSC900 system, Eren requested that its entire fleet be installed with 3D grade control technology. In total, Trimble dealers installed 16 GCS900 dual GPS systems and one GCS900 with total station; the equipment is rotated as needed and used primarily on excavators, motorgraders, bulldozers, and a rock drill.
Within a month the teams worked together to equip the machine fleet with Trimble and preform the required data preparation, machine calibration, site calibration, and operator training. With the adoption of the new system, The dealer helped to precisely measure the machines and calibrate the sensors for accurate operations, including taking into account normal machine wear and tear including: loose mechanics, worn parts, and hydraulic leakage. Prepping the location and design data and creating accurate 3D designs, in addition to CAD drawings, was a necessary step to putting the design inside the machine's cab and on the operators screen.
"There is still accurate survey work needed to make GPS machine control workable, it's just a different set of requirements," said Alporal. "Upfront and accurate site calibration to transform the parameters of GPS coordinates into the design coordinates, for instance, is a critical. But, the more consistent and proactive you are with data preparation and design accuracy, the more the project will run efficiently going forward. The bottom line is, life will be easier, but it will have different requirements."
The dealer worked with surveyors, IT specialists, machine chiefs and operators to get them up-to-speed on the grade control equipment. Within weeks the crew was trained to calibrate a new bucket, to check and recalibrate teeth distance, base station and repeater positions, and more. The team also built the foundation for restructuring roles and responsibilities such as giving the Earthworks Foreman more responsibility. Communication channels were also shifted to make jobsite production even more effective when using Trimble.
As a result of using the Trimble GSC900 solution, Eren Construction completed the 63 kilometer irrigation channel about 30 percent faster than anticipated. The estimated cut was14,000,000 cubic meters and the fill reached 3,200,000 cubic meters. The Trimble dual GPS antenna system ensured extreme accuracy and course and blade position resulting in fewer errors. This visibility inside the cab and increased precision helped to reduce material overages throughout the course of the entire cut and fill process. Overall the project realized a remarkable savings in concrete usage.
Alporal believes that greater jobsite productivity and fuel savings only tell part of the story. When months or even a year is shaved off a project timeline, heavy highway equipment is not used as hard and machine hours are kept lower than anticipated. This means less maintenance and repair time is needed and machines can be reallocated to new projects more quickly, keeping them running and profitable. This translates to an even stronger return on investment for Trimble customers. Plus, contracts can redeploy the GSC900 solution on other equipment for other projects- bringing down the total cost of the initial investment.
"For projects of this scale, velocity of processes and greater grade accuracy are also very significant benefits of Trimble 3D machine control," said Imer, manager with SITECH Eurasia. "Fewer human errors, less repetitive work, and the streamlined division of responsibilities also give contractors an advantage in staying competitive and earning new business in a market with such tight margins."