Weep holes are small drainage openings placed near the base of retaining walls, compound walls, wing walls, and other underground structures so trapped water can escape. A typical weep hole is a round or square opening about 0.1 m, or 100 mm, in diameter that lets water drain from the backfill side to the exposed […]
Corrosion is the slow conversion of a metal back into the ore it came from. Iron and steel, the backbone of most structures, react with oxygen and moisture in the environment and form oxides and hydroxides that have none of the parent metal’s strength. The process does not stop at the surface: rust expands, cracks
Every geotechnical report, boring log, and specification sheet in modern construction relies on the Unified Soil Classification System (USCS) to describe earth materials in a way that engineers everywhere understand. Arthur Casagrande proposed the original form in 1942 for airfield construction work carried out by the Army Corps of Engineers during World War II. The
Every foundation transfers the weight of a structure into the ground, and the soil must be able to carry that weight without failing in shear or settling too far. When the ground beneath a footing cannot resist the applied pressure, the foundation can sink, tilt, or rupture, and the damage often appears first as cracked
A column is the vertical structural member that carries the dead and live loads of a building from beams and slabs down to the foundation. In a framed structure the column works as a compression member, shortening slightly under load instead of bending, and its effective depth is at least three times its side dimension,
Every slab, beam, girder, and column in a building carries a share of the total load. Before any member can be sized, the engineer must know how much load it receives, and that depends on which parts of the floor or roof feed into it. The tributary area is the loaded region that contributes load
Soil forms through weathering, the physical breakdown and chemical alteration of earth materials at the surface. Rain, wind, temperature swings, and biological activity break rock into progressively smaller particles, and those particles do not always stay where they formed. When moving water, wind, glaciers, gravity, or human activity carries weathered material to a new location,
An estimate is the anticipated cost of a project, calculated well before the work starts. The probable cost is worked out by computing the quantities required and pricing them at reasonable rates, so the owner understands the expense likely to be incurred before committing to the scheme. The exact cost is only known from the
Brick masonry is a structural element built from bricks and cement mortar. Different qualities of brick are combined with different mortar mixes depending on the architectural design and the loads the wall will carry. The bricks are placed according to a design bond so that they knit together into a wall that can safely withstand
Steel frames handle gravity loads well, but they sway under wind and earthquake forces. Beams and columns are sized to carry vertical loads, while a separate set of members called bracing keeps the frame stable against lateral forces. Bracing reduces lateral deflection, controls buckling of the main beams, and transfers horizontal loads down to the
