4 ms·
In the book the issue was that the sand around, and eventually under, the foundations washed out over time so the piers started to be effectively suspended from
by prennert 6y ago
In the book the issue was that the sand around, and eventually under, the foundations washed out over time so the piers started to be effectively suspended from the bridge rather than supporting it. Rubble around the actual foundations were needed to defuse the drag of the water around the foundations, preventing the washout.