This paper examines the feasibility of using calcium-based biocement to form an impermeable crust on top of a sand layer. The biocement used was a mixture of calcium salt, urea, and bacterial suspension, which hydrolyzed urea with production of carbonate and an increase of the pH level. Applying 0.6 g of Ca per c m 2 of sand surface, the permeability of the biocemented sand can be reduced from ...

Coastal erosion of low latitude beaches frequently results in exposure of beachrock, layers of beach sand cemented in the subsurface by the intergranular precipitation of calcium carbonate. Exposed beachrock can have a profound impact on the event, seasonal, and long-term morphodynamics of a beach. The influence of beachrock on beach processes will largely depend on the extent and morphology of...

4 A newly emerging microbiological soil stabilization method, known as microbially 5 induced calcite precipitation (MICP), is tested for geotechnical engineering 6 applications. MICP is a promising technique that utilizes the metabolic pathways of 7 bacteria to form calcite precipitation throughout the soil matrix, leading to an increase 8 in soil strength and stiffness. This paper investigates...

Burrowers and borers are ecosystem engineers that alter their physical environments through bioturbation, bioirrigation and bioerosion. The mechanisms of moving through solid substrata by burrowing or boring depend on the mechanical properties of the medium and the size and morphology of the organism. For burrowing animals, mud differs mechanically from sand; in mud, sediment grains are suspend...