Chilean Tunneling Projects: Leverage Innovative Geospatial Technologies With Guidance from GEOCOM
For nearly four decades, customers in a wide swath of disciplines—including mining, construction, engineering, infrastructure, marine and civil—have relied on GEOCOM and Trimble® to provide the guidance, product solutions and training needed to safely and productively complete demanding tunneling projects using innovative geospatial technologies. Explore how GEOCOM has partnered with their customers to ensure success on their tunneling projects.
Colbún, Los Andes, Chile
Surveying contractor Rumbos Geomensura faced challenging environmental conditions to capture a detailed as-built of this existing utility tunnel survey project. The task, which included creating a topographic representation of a 4.4 mile-long water transportation tunnel in order to update hydraulic computations, lacked an established geodetic survey control network.
GEOCOM Solution: Rumbos Geomensura utilized the Trimble SX12 total station to allow for high accuracy data capture using the scanning function and robotic total station to perform the traverse measurements. The SX12’s robotic mobility feature was instrumental to enable measurements further from the total station in GNSS-devoid environments. The survey control network was established and verified using Trimble GNSS receivers and Trimble Business Center (TBC) software to process the baselines for the utmost accuracy.
Using TBC software, along with the Trimble TX8 3D scanner, tunnel survey data was captured with accuracy and speed. The technology allowed Rumbos Geomensura to make informed decisions in a timely manner, keeping the project running safely and efficiently. The TX8 also allowed Rumbos Geomensura to manage several tunnels throughout this project and create cohesive work templates with TBC to deliver high-quality data to project stakeholders.
This two-part article offers a more robust description of the project (Part 1 and Part 2) including images, data charts and detailed project video coverage. This video details the data capture process with the SX12 and TBC. Please refer to the following article.
Underground Tunneling Project
The customer wanted to conduct real-time tunnel construction quality control on shotcrete layers as soon as they are applied to increase productivity in the process and remove unnecessary processing steps.
GEOCOM Solution: Tunneling technology, including the Trimble SX12 total station with Trimble Access software, allowed this customer to:
- Conduct real-time inspections from a captured point cloud for construction verification, as well as the tunnel design, measuring surface and underground areas.
- Complete shotcrete inspections, comparing the tunnel’s before and after concrete application, allowing identification of shotcrete thickness differences while on site.
- Ensure the proper quantity of shotcrete was applied to ensure structural stability.
This project team wanted to address construction challenges before they became issues, keeping this tunneling project running smoothly and according to schedule.
The combination of the Trimble X7 laser scanner and Industry Foundation Class (IFC) files for 3D BIM design models allowed the customer to quickly view survey data compared to the design model in 3D and address any potential construction deviations collaboratively with project stakeholders.
Some of the construction was prefabricated in controlled environments, and teams needed to have the correct tools for design completion in the field for proper quality control. Every deviation in the construction design would impact the planning and quality of later stages, potentially triggering delays and cost overruns.
The Trimble X7 was instrumental in analyzing the geometric obstacles throughout construction. Trimble Connect was utilized to collect the geometric information needed to make informed decisions in planning meetings. The following processes and deliverables were included on this project:
- 15 scan station locations captured at medium density
- Field point cloud alignment (registration)
- Point cloud import directly to Trimble Connect for comparison with IFC design files
- Visual progress reporting on construction and analyzing possible restrictions of upcoming construction activities
GEOCOM added this video of the project, and see image below.
Underground Tunneling Project
The customer wanted to utilize high resolution 3D design models in the field during underground construction activities to visualize potential conflicts and validate the final as-built position, removing the need for time consuming analysis in the office and avoiding potential construction conflicts by diagnosing them before construction activities commence.
GEOCOM worked with the customer to utilize a Trimble SX12, along with Trimble Access and Trimble Connect to manage and share 3D models on site for this tunneling project. Trimble Connect served as a tool for coordinating geospatial information such as point clouds, survey measurements and design models.
The Trimble Access field survey application allowed the customer to connect the BIM design with the measured terrain model in the field, and in a direct and simple way. This improved the visibility of project progress and allowed the team to anticipate future geometric interferences that could delay construction. By directly importing the design model into the total station field software, project teams avoided intermediate steps that can cause errors and delays. The dynamic use of the design model in the field through augmented reality allows for real-time decision making during underground construction.
This video shows the design of an underground mine and its progress, as well as the necessary infrastructure for its development. See image below.
AVO Highway Project
The customer needed to compare multiple sections of a tunnel and verify the tunnel as-built geometry.
The Trimble SX10 and Trimble SX12 helped deliver efficient and highly accurate results. The team benefitted from robotics in underground work in addition to the flexible total station traverse observations for the control network that guided construction equipment. With Trimble Business Center software, they were also able to produce a survey network with the high precision and accuracy needed for high impact tunneling construction projects like this one.
This video demonstrates the capture of point clouds for tunnel construction.
Visit the GEOCOM and Trimble Geospatial websites to learn more about innovative geospatial technologies to solve your toughest tunneling challenges.