Liquefaction Mitigation: Seismic Adaptation Measure


Installation at night © Fugro and SGH


TARGETED MEASURE:
TYPE: Geotechnical

SHORELINE LOCATION:
Landside


DESIGN LIFE
ADAPTABILITY
IMPACT ON THE WATERFRONT
CONSTRUCTION COST
100+ Years
Low
Minor Intervention
Moderate


SEISMIC HAZARDS MITIGATED:SEISMIC PERFORMANCE IMPROVED:
Lateral Spreading
Liquefaction
StructuresUtilities & Transportation


MEASURES COMPATIBILITY:
Flood
Seismic
None
Shoreline Stabilization

Bulkhead Wharf Retrofit

Utility Retrofit


DESCRIPTION:
Strengthened in situ soils (fill only) landside of the existing shoreline. This would mitigate liquefaction-induced settlements that would otherwise damage the Embarcadero, the promenade, the light rail and utilities.


CONSIDERATIONS:
ADVANTAGES:
DISADVANTAGES:
  • Locations of soil improvement determined by exposure of utility and transportation system components to liquefaction as well as accessibility to the liquefiable fill from the ground surface.
  • Soil improvement would be limited to the liquefiable fill below the water table.
  • Measure specifically targets the soils which cause liquefaction-induced settlements.
  • Requires less utility relocation work than landside shoreline stabilization measures.
  • Waterfront buildings can remain occupied during construction.
  • No in-water work.


  • Does not mitigate lateral spreading due to shoreline instability.
  • Reduces but does eliminate vertical displacements due to shoreline instability.
  • Requires careful monitoring of utilities during construction.
  • Difficult to access fill below light rail track slabs.



CONSTRUCTION IMPACTS TO THE PUBLIC:
SEA LEVEL RISE ADAPTATION OPPORTUNITIES:
  • Construction could occur mostly at night with evening closure of the Embarcadero, promenade and light rail guideway.
  • Impacts to users of the promenade and the Embarcadero would likely be limited.


  • This measure does not present any opportunities for sea level rise adaptation.



DESIGN CONSIDERATIONS:

  • The heterogeneity of the fill would make it difficult to achieve a uniform density and strength using liquefaction mitigation.

SITE-SPECIFIC CONSIDERATIONS:

  • Areas with a high concentration of utilities and/or large sewer structures would limit access to the fill below and may compromise the effectiveness of the improvement.

URBAN DESIGN CONSIDERATIONS:

  • This measure does not present any urban design opportunities or considerations.

HISTORICAL RESOURCE CONSIDERATIONS:

  • This measure would not impact any historical buildings

INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • This measure would require closely spaced grid of injection points while avoiding existing utilities.
  • Drilling through light rail track slabs to access the fill would be required.
  • Monitoring of utilities during grouting operations would be required.


Download the Liquefaction Mitigation Factsheet.

Learn about other types of measures from our Measures Explorer page.



Installation at night © Fugro and SGH


TARGETED MEASURE:
TYPE: Geotechnical

SHORELINE LOCATION:
Landside


DESIGN LIFE
ADAPTABILITY
IMPACT ON THE WATERFRONT
CONSTRUCTION COST
100+ Years
Low
Minor Intervention
Moderate


SEISMIC HAZARDS MITIGATED:SEISMIC PERFORMANCE IMPROVED:
Lateral Spreading
Liquefaction
StructuresUtilities & Transportation


MEASURES COMPATIBILITY:
Flood
Seismic
None
Shoreline Stabilization

Bulkhead Wharf Retrofit

Utility Retrofit


DESCRIPTION:
Strengthened in situ soils (fill only) landside of the existing shoreline. This would mitigate liquefaction-induced settlements that would otherwise damage the Embarcadero, the promenade, the light rail and utilities.


CONSIDERATIONS:
ADVANTAGES:
DISADVANTAGES:
  • Locations of soil improvement determined by exposure of utility and transportation system components to liquefaction as well as accessibility to the liquefiable fill from the ground surface.
  • Soil improvement would be limited to the liquefiable fill below the water table.
  • Measure specifically targets the soils which cause liquefaction-induced settlements.
  • Requires less utility relocation work than landside shoreline stabilization measures.
  • Waterfront buildings can remain occupied during construction.
  • No in-water work.


  • Does not mitigate lateral spreading due to shoreline instability.
  • Reduces but does eliminate vertical displacements due to shoreline instability.
  • Requires careful monitoring of utilities during construction.
  • Difficult to access fill below light rail track slabs.



CONSTRUCTION IMPACTS TO THE PUBLIC:
SEA LEVEL RISE ADAPTATION OPPORTUNITIES:
  • Construction could occur mostly at night with evening closure of the Embarcadero, promenade and light rail guideway.
  • Impacts to users of the promenade and the Embarcadero would likely be limited.


  • This measure does not present any opportunities for sea level rise adaptation.



DESIGN CONSIDERATIONS:

  • The heterogeneity of the fill would make it difficult to achieve a uniform density and strength using liquefaction mitigation.

SITE-SPECIFIC CONSIDERATIONS:

  • Areas with a high concentration of utilities and/or large sewer structures would limit access to the fill below and may compromise the effectiveness of the improvement.

URBAN DESIGN CONSIDERATIONS:

  • This measure does not present any urban design opportunities or considerations.

HISTORICAL RESOURCE CONSIDERATIONS:

  • This measure would not impact any historical buildings

INSTALLATION AND CONSTRUCTABILITY CONSIDERATIONS:

  • This measure would require closely spaced grid of injection points while avoiding existing utilities.
  • Drilling through light rail track slabs to access the fill would be required.
  • Monitoring of utilities during grouting operations would be required.


Download the Liquefaction Mitigation Factsheet.

Learn about other types of measures from our Measures Explorer page.