Bricklining

Bricklining is the process of applying a brick masonry interior lining to the walls of an existing hollow structure, such as a tunnel, sewer, culvert, canal tunnel, or mine passage, to restore structural integrity, improve water-tightness, and preserve cross-sectional geometry. It has historical roots in masonry-based civil engineering, emerging prominently in the 18th through 19th centuries for urban sewer networks and industrial tunnels. Bricklining is typically undertaken to repair cracked or deteriorated linings, to provide a new hydraulic surface, or to resist groundwater and ground pressures.

Construction methods generally involve laying bricks in mortar directly against the existing lining or to a temporary framework, forming a continuous ring that conforms to the tunnel profile. Mortars used range from lime-based mixes in older work to cementitious mortars in later practice. Joints are keyed and pointed to reduce seepage, and the brickwork may be reinforced with ties or encased in a protective backing, depending on the structure and site conditions.

Advantages of bricklining include durability, fire resistance, and the ability to create a relatively smooth, corrosion-resistant interior surface. It can restore circularity and load distribution and, when executed properly, achieve satisfactory hydraulic performance. Disadvantages include labor intensity, high cost, and vulnerability of mortar joints to deterioration; bricklining can be less adaptable to ground movement and is often heavier than alternative linings.

Today, bricklining is largely superseded by concrete, shotcrete, or segmental linings in new work, though it persists in restoring or maintaining historic structures and in specific applications where original materials are preserved.