Stabilization Along the Pacific Coast Highway
Along the coastal cliffs of California is the Pacific Coast Highway, which stretches across nearly every part of the California Coast. But along this scenic beauty lies a battle against natural. Originally build as a crucial transportation link, the PCH now faces daily challenges from the earth it was built upon.
Engineers found themselves confronting a relentless challenge: the unstable coastal slops. As rain saturates the ground and seismic activity shakes the foundation, sections of the highway face constant threat of collapse. To combat this, civil engineers developed a variety of innovative solutions. Within the bedrock, powerful ground anchors and soils nails work like the roots of trees, holding the ground in place. Steel cables, which are stretched tight and anchored deep in stable rock, create nets that keep unstable soil masses from tumbling onto the roadway.
But engineers did not stop at this. They created a early warning system across the coast, which was comprised of a network of electronic sentinels that worked at all times. Within the slopes, inclinometers measure the ground movement while piezometers track the pressure of groundwater that may cause disaster. GPS monitoring points, accurate to the millimeter, are ready to alert teams when danger approaches.
When choosing solutions, engineers must balance cost against effectiveness. In the case of the Mud Creek landslide in Big Sur, engineers chose not to stabilize the original slope. Instead, they built a new road section over the slide mass, which proved to be more practical than alternatives.
Today, the PCH serves as a laboratory for coastal and geotechnical engineering. Each new challenge teaches valuable lessons, leading to innovative solutions like lightweight fills (which do not burden the slopes) and improved drainage systems (which guide water away from risky spots). Native plants are also allies for civil engineers, as their roots hold soil in place while maintaining the coast’s natural beauty. Engineering along this coast is a model of civil engineering ingenuity, where human determination meets the power of nature along the California coast.
