The North Luzon Expressway extension project, Philippines. A problematic section known as "Km 47," where the ground is as soft as puto (rice cake) and twice as treacherous.
Mang Lito squinted. "Or we do compaction . The old way." geotechnical engineering mathalino
She flipped her yellow pad. "Look at the (FS). For highway embankments, FS must be 1.5 against bearing failure. Right now, FS = (q_ult/q_allowable) = 120/200 = 0.6. That is not an FS. That is a recipe for a sinkhole." The North Luzon Expressway extension project, Philippines
This story is inspired by the thousands of Filipino engineers who use to master the math behind the mud. "Or we do compaction
Mai was ready. "Bearing pressure ((q)) is load ((P)) divided by area ((A)). Yes, if I double the width, I halve the pressure—in theory. But in geotech, scale matters . A wider footing on soft clay doesn't spread the load; it just sinks like a pancake because of the ."
"You cannot change the friction angle ((\phi)) of the native soil without replacing it. But you can increase the normal stress ((\sigma)) by surcharging. Or you can add cohesion ((c)) via grouting."