​U.S. 202 (Dekalb Pike) ​​Sinkhole Remediation Project​​

County: Montgomery
Municipality: Upper Merion Township
State Route(s): U.S. 202
Local Name(s): Dekalb Pike
Project Type: Sinkhole Remediation
Last Updated: March 2026

The U.S. 202 (Dekalb Pike) sinkhole remediation project will provide a long-term solution to address repeat sinkholes that have occurred within the roadways. The proposed work will be completed along U.S. 202 (DeKalb Pike) in Upper Merion Township, Montgomery County, between Henderson Road and Saulin Boulevard.

The proposed scope of work includes a limited mobility grouting program that will involve drilling holes through the pavement in a “grid” pattern. Pressurized grout will be injected into the drilled holes to fill subsurface voids beneath the roadway. The filling of subsurface voids will help stabilize the ground beneath the pavement and reduce the risk of future sinkholes. Additional proposed work for this project includes drainage pipe replacement and pavement reconstruction.

Stage 2 construction will begin on Thursday, February 26, to repair and reconstruct southbound U.S. 202 (Dekalb Pike) under a $22.4 million project to provide long-term sinkhole remediation on U.S. 202 (Dekalb Pike) in Upper Merion Township, Montgomery County, and on Route 29 (Morehall Road) in East Whiteland Township, Chester County.

Motorists are advised of the following travel restriction:

• Thursday, February 26, through late fall 2026, southbound U.S. 202 (Dekalb Pike) be closed and detoured 24/7 between Prince Frederick Boulevard/Saulin Boulevard and Henderson Road.

During the closure, motorists will be directed to use Saulin Boulevard and Henderson Road. Local access will be maintained at all times to residences and businesses.

PennDOT reopened northbound U.S. 202 North (Dekalb Pike) between Henderson Road and Saulin Boulevard on Tuesday, November 4, 2025, following eight months of construction to repair and remediate sinkholes under Stage 1 of the project.

Remediation of sinkholes on U.S. 202 (DeKalb Pike) were deemed necessary for a long-term solution following reoccurring sinkholes and emergency repairs resulting in traffic disruptions along both corridors.

Heidelberg Materials, LLC of northeast region, is the general contractor on this project, which is financed with 100 percent federal funds.

Fixing sinkholes on U.S. 202 is a massive engineering puzzle that goes way deeper than the pavement!

The geology under a sinkhole is unpredictable. Under the surface, bedrock depth can shift by 60ft in just a few steps. Our crews often drill over 100 feet deep, and we don’t stop until we’ve penetrated 10 feet of solid rock to ensure a permanent fix.

Why does it take so long?

Drilling through solid rock takes much longer than drilling through soil —about 5-10 minutes for every 10 feet. With hundreds of holes to drill and specialized equipment to move, it’s a time-consuming process.

Once the holes are ready, we use Low-Mobility Grouting. Think of it as an extra-thick, heavy concrete pumped deep underground. Unlike regular concrete, it stays in a tight bulb, using high pressure to squeeze and compact the soil, filling hidden voids and stopping sinkholes before they start.

Click here to watch how that drilling happens!

Limited mobility grouting is a ground stabilization method used to strengthen soil and rock below the roadway surface. This strategy is often used in areas where voids or unstable ground conditions may exist. The process involves drilling small diameter holes through the ground and into the underlying rock, installing steel riser pipes, and injecting a stiff, mortar-like grout mixture. The mixture is made of water, Portland cement, and filler materials such as sand, or fine aggregate. This grout is pumped into the hole until the hole is filled. The grout stabilizes the ground mass beneath the roadway by filling underground voids and compacting loose or weak soils.

Although the work takes place within a relatively small surface area, the process is highly controlled and methodical, which can make it appear slower than other construction operations. Each stage of grouting must be carefully monitored for pressure, grout volume, and ground movement. Close monitoring ensures the material fills underground spaces properly without causing damage to nearby utilities, pavement, or structures. In many cases, crews set up the equipment and initiate pumping. After that, the grout pump continues injecting material under controlled pressure while an operator monitors gauges and readings until specific termination criteria are reached.

During this time, fewer workers may appear active in the work zone because the equipment is performing the pumping while the operator oversees the process. Crews may also pause between stages or holes to review data, reposition equipment, or allow grout to settle or cure. Crews also may need to adjust the plan based on subsurface conditions encountered. As a result, motorists may occasionally see periods where little visible activity is occurring, even though monitoring, preparation, and quality control work are still underway to ensure the stabilization is completed safely and effectively.