Why Timely Bulkhead Repair Matters
                     How Piers Are Designed 
and Built
An educational overview of pier engineering, from forces to finished 
structure.
What we'll cover
1. Pier fundamentals
2. Design and load path
3. Materials and building
4. Lasting structures
02.
Every pier reduces to three parts
Piles reach the seabed, the deck spans above them, and the 
superstructure sits over the deck.
Foundation piles
Transfer load into the seabed
Deck
The walking surface
Superstructure
Railings, shelters, buildings above
Water and load pull four ways 
Waves Currents Tides Live loads
Sideways impact plus Steady drag on every pile Water line swings meters, Moving weight of people, 
upward lift sets deck height vehicles, goods 
End-bearing pile Friction pile
Load rests on hard rock below Load held by soil grip along the shaft
Piles push down until they hit firm rock or dense soil, then Where no hard layer sits within reach, the pile relies on 
send the load straight into that hard layer. friction with surrounding soil over its full depth.
Test the seabed first: the ground decides which pile type carries the pier.
Load runs deck to seabed 
Weight spreads before it Piles carry rising stress to 
descends seabed
• Deck surface receives the load first • Load concentrates as it moves down the 
• Beams and girders spread it to supports pile
• Pile caps hand the load to each pile • Seabed absorbs it through bearing or 
friction
• Every joint in the chain must pass the 
load on intact 
Materials trade cost for lifespan 
Every material buys either a lower price or a longer life, never both.
Timber Low cost, shortest life
Moderate cost, 
Concrete
longest life
High strength, needs 
Steel
corrosion protection
Choose by how long the pier must last, then price the maintenance that comes with it.
07.
Building over water runs in order
1. Survey and 2. Drive piles 3. Cast pile caps 4. Set beams 5. Lay deck
mark
Into the seabed Tie piles together Span between caps Then add 
Locate pile positions superstructure
08.
Piers are built to resist decay 
Decay never stops working
Salt, growth, and hidden wear attack every pier from day one.
Corrosion
Salt attacks steel and 
rebar
Marine growth
Adds weight, traps 
moisture
Splash zone
Worst wear at the tide 
line
Maintenance
Inspect, coat, replace on 
schedule
09.
A pier is one load path, seabed to deck
Every design choice, from piles to materials, exists to move that load safely down.
Three parts, one structure Load and water pull in five stages Build order fixes material choice
Piles transfer load into the seabed. The deck carries the Weight moves deck, beams, pile caps, piles, then seabed. Piles are driven, capped, and beamed before the deck is laid. 
walking surface. The superstructure sits above, holding Waves hit sideways, currents drag steadily, tides set deck Timber costs least but lasts shortest, concrete lasts longest, 
railings and shelters. clearance, and live loads shift on the surface. steel is strongest but needs corrosion protection.
End-bearing piles rest on rock; friction piles grip soft soil Salt corrosion and marine growth hit hardest at the splash 
along their shaft. zone, so scheduled inspection sets the true lifespan.
Thank you
Thanks for following the build.