Erath quakes: damage mitigation

 

Earthquakes: not the quake, but liquefaction of the soil causes most damage Solid ground can suddenly change to quicksand

Solid ground can suddenly change to quicksand

Safety guarantees of all built structures, whether a bridge, road, railway, or dam, depend on the subsoil stability. As populations increase, built-up area and infrastructure vulnerability to natural disasters increases, particularly in low lying areas. Subsidence and sea level rise exacerbate such hazards, Preventative measures greatly reduce the risk of enormous damages. Liquefaction of normally very stable sand layers occurs when water pressure exceeds the overburden pressure. Sand grains momentarily loose their coherence and the soil with everything on it slumps instantaneous.

Preventing damage

Natural earthquakes cannot be prevented. There effects can well be mitigated by:

  • Ensuring that water pressure cannot exceed a level where liquefaction may occur;
  • Cementing sand grains togethers, preventing liquefaction;
  • Enclosing the sand layer, so that even during liquefaction, the sand grains have no way to ‘move’.

Bioinspired solutions

BISI offers solutions to implement all these mitigation methods in a single process.

We make natural soil bacteria produce nitrogen bubbles (N2 gas), that act as mini air bags. Gas is very compressible, allowing gas bubbles to dampen earthquake related shock waves. Working with USA laboratories, we implemented tests that demonstrate that liquefaction becomes impossible. Formation of sufficient gas in the subsoil takes a mere few days. A small degree of desaturation suffices to prevent liquefaction. We also have the natural soil bacteria produce natural cements, the natural mineral calcite, cementing soil grains together. Calcite formation and gas bubble production are both par of the same in situ biological process.

Milieu-onderzoek

Wij engineeren de uitvoering van een project. Van bodemonderzoek tot detailontwerp van saneringsmaatregelen.

Pilotproeven in het lab

Wij beschikken over onderzoeksfaciliteiten om oplossingen te toetsen voordat we overgaan tot uitvoering in het veld.

Inpassing in infra en ontwikkeling

De bodemsanering staat niet op zichzelf maar maakt onderdeel uit van de ontwikkeling van een locatie of nieuwbouw.