Big concrete pours are major milestones for every ground-up project and even with all the inspections, double checks, and job walks there are still countless things that can go unnoticed and cause issues. Shop drawings aren’t always perfect and the responsibility to get it right almost always ends up falling on the GC. Truebeck said, “One thing with concrete is that you only get one shot to do it right, so this was our one shot, and we got it right.”

Laser scanning gets an exact representation of what is built in the field and can catch issues that are even missed in the shop drawing reviews. At the Millbrae Station project Truebeck did two scans: one for vertical dowel placement, and one for concrete volume calculations.

Truebeck scanned on site into the late afternoon on Thursday with the pour scheduled to start at 2 a.m. on Saturday. The first scan captured where each vertical dowel was placed, and that data was overlaid with the structural plans. Each set of dowels should show up right in the middle of each column in the structural plans, but one column was off by about 4”-6”. This particular column is offset from the gridlines in the structural plans, but the rebar shop drawings showed the dowels centered on the grid intersection.

Truebeck said, “We were able to get the iron workers to move the dowels and we were able to cast the slab with the dowels in the correct location,” Truebeck then added, “Had we not caught it we would have had rework, drill and epoxy work.”

Avoiding mistakes on major concrete pours has several advantages. Obviously, you avoid rework which wastes time and money, but it also gives the design team and owners confidence that we are doing our due diligence and keeps the project rolling forward.

The second part of the pre-pour scanning work by Truebeck was done to get an accurate volume of concrete for the pour based on real world conditions. The rat slab and shoring walls are not perfectly plumb and level which can throw off volume calculations. Truebeck explained that their original take off was 3278 yards, but the scanned result estimated 3340 yards. “It was great to have that dialed in and give our engineer some confidence heading into the pour,” Truebeck said, “It took the guess work out of it.”

Laser scanning before major concrete pours is an effective and efficient way to catch mistakes, and make a plan that minimizes variables. Truebeck summed it up best saying, “It makes everyone look like heroes.”

Background: Truebeck Construction received a laser scan from the client upon award of the project, but quickly determined that the point cloud wasn’t registered properly and was not conducive for performing a floor flatness study. Siteline was called in by Truebeck to scan the interior and exterior façade. Truebeck was tasked to add an exterior door and needed to validate the grade differences between in the inside and the outside of the door. The civil engineer had done a previous study and projected a 5” difference in elevation. (higher on the exterior).

Siteline Service: Siteline used a Leica RTC 360 to scan the space. Leveling the scanner before each scan, Siteline scanned the interior and the exterior of the space. After the scan was complete, a specific location on the floor was set as the benchmark elevation. Once the scan was located and elevated, Siteline provided the team with both a point cloud as well as a topographic survey that was produced using Rithm for Jetstream.

Findings: After scanning and analyzing the data, Siteline determined that the existing sidewalk adjacent to the proposed new door location is closer to +7” as opposed to the original survey elevation of 5”.

Proposed Solution: To make the sidewalks ADA Compliant, more modifications needed to be made than originally anticipated.

Value Add: Siteline’s team got involved in the Bay Health Ambulatory Surgery Center project very early and performed this scanning effort while the project was still being designed. Having this information at this point in the project allowed the team to work together to determine a code compliant construable solution that could be incorporated into the design drawings and included in the budget before an agreed upon GMP.

Sometimes a design simply can’t be built the way it’s shown on paper. We experience this in some capacity on every project, but even the smallest deviation can cause serious headaches, especially when that project is an active hospital. When the as-built drawings show one thing, and the real condition is different, your project can grind to a halt while the design team addresses the issue. To deliver a successful project in a timely manner, design deviations need to be addressed as early in the design process as possible.

For the Imaging Equipment Replacement project at El Camino Hospital in Mountain View, the challenge was exacerbated because any days lost to field delays directly affected when the imaging equipment would be back up and running for the hospital to use. Hospitals depend very heavily on their imaging equipment, so minimizing the project duration and equipment down time was critical to the project success. In an effort minimize delays caused by unforeseen field conditions, Truebeck hired Siteline to laser scan, 360 Image capture, identify, and 3D model the existing overhead utilities down to three-quarters of an inch.

Siteline’s utilized a NavVis VLX laser scanner and 360-degree cameras to produce both an as-built model, as well as a library of 360-degree photos showing everything above the ceiling that needed to be taken into consideration. The 360-degree photos were captured and organized using Cupix, an online platform, which shows each photo in a 3D space to jump from one perspective to another. Truebeck’s project manager, and project engineer, have utilized the Cupix photos in many ways.

According to team, they have used the Cupix photos in about half of their total RFIs to date and often use them in owner’s meetings. Truebeck said, “When a trade partner has a question we can shoot them a link to that exact location,” while Truebeck added, “We’ll find a conflict, but our team isn’t sure who’s utility it is, so we show it to the owner, and they tell us who owns it.”

The ability to visualize conflicts and answer questions quickly keeps everyone on the same page and helps foster an environment based on open communication. “It snowballs,” said Truebeck, “It keeps the momentum going forward so we can keep building.”

The effort to gather all this information was no easy task. Siteline worked closely with the hospital to schedule work late into the night to avoid disrupting hospital activities during the day. Truebeck said, “It took a bit of money and time up front to get to where we are, but if we hadn’t done it then it would likely be more problematic and costly later.”

Where everything ends up above the ceiling is often a hectic mystery, but by taking the time to gather real information and organize it via Cupix in an easy-to-navigate format; the team at El Camino Hospital has reduced the time to fix field issues from days or potentially weeks, down to hours or even just minutes. Truebeck remarked, “This project wouldn’t be the same without this technology.”

El Camino Health, Imaging Department

Equipment Replacement

Mountain View, CA

CHALLENGE

Coordinate the replacement of imaging equipment and supporting utilities around existing utilities and structure with unverified as-built documentation. The coordination was extremely critical to accurately plan and phase construction to minimize disruption to the hospital and operation of the equipment.

SOLUTION

Siteline performed a thorough site investigation utilizing 360 photography and lidar (light detection and ranging) technology to capture all existing conditions. The delivered as-built model helped the team accurately locate and identify all of the existing elements and define routes for new utilities.

VALUE

During the coordination process, the team discovered hundreds of discrepancies between the original design documents and the captured existing conditions. This allowed the team to update the design drawings and get AHJ (OSHPD) approval prior to mobilization. The as-built scan and model helped the team discover early in the coordination phase that the new equipment design would not work with the existing structure. Once discovered, the team worked with the equipment manufacturer to modify the design. The design modification took over six months, which would have resulted in a construction delay if the as-built model and scans hadn’t been available.

DivcoWest, 550 Terry Francois Blvd

Life Science Facility

San Francisco, CA

CHALLENGE

As the construction team started removing the raised access flooring in this office to lab conversion project, they quickly realized that the floors were very out of level and had varying thickness. The deviations were so drastic that ADA slope requirements and minimum thickness for structural loading were of concern. In addition to the floors within the building, there were also ADA concerns regarding the site’s hardscape.

SOLUTION

Siteline laser scanned the entire building and site and generated reports for floor flatness, floor and site hardscape slopes, and deck thickness. The same scan results were also used to as-built existing utilities for coordination of the new lab scope.

VALUE

The flatness and slope reports helped the team determine which areas of the floors and site did not meet ADA requirements and how to fix them. The thickness report helped the structural engineer calculate the allowable loading of each structural bay in the building.