Fast and Accurate Staking of Road Slopes and Surfaces with the Leica AP20 AutoPole

Surveying and construction professionals face rising pressure to execute high-accuracy tasks faster than ever despite increasingly complex projects, ambitious deadlines, and tight budgets. Add a growing shortage of skilled labour within the industry, and it is easy to see that selecting the easiest and quickest method to survey or set out is critical to success.

One way to integrate new methods with maximum returns is by adopting technology that fits existing workflows and speeds up productivity on the most traditionally time-consuming and common tasks. The Leica AP20 AutoPole is one such technology - a pole-side innovation that enables construction surveyors and layout engineers already using a Leica Geosystems robotic total station to measure with a tilted pole, among other game-changing features. But what level of impact does this really have on the overall workflow? 

Paul Dainty, Filip Barat and Georgios Savvoulidis Product Engineers at Leica Geosystems with expertise on the AP20, provide details on the instrument’s innovative capabilities and how they enable significant productivity increases compared to traditional measurement methods. Using the test case of staking batter rails and profile boards, they demonstrate the time and effort saved while maintaining high-accuracy layout. 

A unique solution for common surveying and construction tasks

The Leica AP20 is a revolutionary innovation that benefits measurement professionals, from surveyors to construction experts, including foremen, MEP installers, layout engineers, and layout specialists who seek easy-to-use solutions that fit into their current workflows. Featuring an intelligent sensor module mounted on the AP reflector pole, the AP20 delivers functionalities with clear benefits on construction sites. 

Tilt Compensation enables construction surveyors and layout engineers to measure and stake with a tilted pole, bringing difficult locations easily within reach. Also making measuring easier, the sensor automatically detects pole height changes, which are immediately recorded in the software. This allows users to freely adapt to the site environment, adjusting the pole height as needed without worrying about height record errors. Additionally, and particularly important on busy construction sites, the robotic total station can uniquely identify the AP20 target during search, preventing locks onto other targets.

This means daily building site layout activities such as staking slabs, columns, MEP, and HVAC installations are performed faster while the probability of errors is minimised. Additionally, using the AP20 for stakeout in heavy construction environments can bring large benefits. For example, the AP20 boosts productivity in almost all measurement tasks during road construction, from stakingearthworks for slopes and gradients to checking final surface levels and the surrounding infrastructure.

Below we examine staking batter rails and profile boards more closely to see how the AP20's benefits are realised across a specific task's workflow using Leica Captivate’s Road app.

The challenges of staking batter rails and profile boards

Setting up batter rails and profile boards for earthworks using a traditional surveying pole and prism can be quite tedious, even when using Leica Captivate’s advanced slope stakeout functionality. First, the two standing pegs of the batter board need to be staked out in the correct position. The pole is moved into position by following the stake values and ensuring the pole is held vertically. 

Once the standing pegs are hammered into the ground, the height of the batter rail needs to be staked and marked accurately onto each of them before the board is nailed into place. A widely used method for this is measuring to the top of the standing peg using a mini prism, and then measuring down the peg by the computed height difference using a standard tape measure.

When comparing the speed of staking the batter rails using a traditional surveying pole and separate mini prism to using the adapted AP20, field tests revealed that the complete workflow of staking batter rails was 36% faster with the AP20. For this task, tilt compensation contributes most to the significant time savings.

When comparing the accuracy of staking batter rails heights, the traditional method using the mini prism and tape measure was considered the most accurate technique and, therefore, used as the benchmark. In comparison, when using the AP20, the field tests showed that the achievable standard deviation of the heights was 6mm. Combined with Leica Captivate field software, the estimated height quality is always visible and the user can set quality tolerances to maintain the required standards. Therefore, surveyors and layout specialists can save significant operational time when using the AP20 while ensuring they have the quality needed for the job – data they can easily share for QA/QC reporting.

What was once considered a challenging scenario for a surveyor or layout engineer, such as measuring difficult-to-reach points, becomes light work when utilising the AP20’s tilt compensation functionality. This benefit can be applied to many stakeout and layout tasks, particularly the staking out of batter rails, where marking heights on the standing pegs is difficult using traditional methods.

The AP20 is accurate, fast, and easy to use, making it a great accessory for anyone looking to increase layout efficiency, reduce costs, and make the most of their time on site.

To learn more about how the AP20 can increase productivity across the measurement professional’s entire workday, read The AP20-Equipped Surveyor expert insight.

 

Paul Dainty

Senior Product Engineer

 

Filip Barat

Product Engineer

 

Georgios Savvoulidis

Intern in Leica Captivate team