Study of a possible alternative progettual solution ofStudy of a possible alternative progettual solution ofStudy of a possible alternative progettual solution of Dubai’s Palm.Study of a possible alternative progettual solution of Dubai’s Palm.

Seismic risk in DubaiSeismic risk in DubaiDubai located in the northern part of United ArabEmirates (UAE) between Arabian Gulf and OmanGulf, because of the particular position near one of

Dubai located in the northern part of United ArabEmirates (UAE) between Arabian Gulf and OmanGulf, because of the particular position near one of, p pthe most seismotectonic areas, is subjected to theeffects of the seismic activity.

, p pthe most seismotectonic areas, is subjected to theeffects of the seismic activity. Bandar-e-Abbas

10/09/2008M = 6 1 Richter

Bandar-e-Abbas10/09/2008

M = 6 1 RichterThe prevalent cohesionlesscharacter of soils and theirusually weak consolidation,

The prevalent cohesionlesscharacter of soils and theirusually weak consolidation,

M = 6.1 RichterM = 6.1 Richter

yhas great importance in thedevelopment of seismic siteeffects.

yhas great importance in thedevelopment of seismic siteeffects.

This conditions put several problems in the planning and monitoring of the territoryurbanisation, since that several phenomenons closely related to the seismicity and theThis conditions put several problems in the planning and monitoring of the territoryurbanisation, since that several phenomenons closely related to the seismicity and the, p y ygeological nature of deposits will be interest the structures insistent.

, p y ygeological nature of deposits will be interest the structures insistent.

As example we report a semplified schematic representation oftwo possible modality of construction of Dubai’s Palm puttingin evidence the various aspects inherent the two possible

As example we report a semplified schematic representation oftwo possible modality of construction of Dubai’s Palm puttingin evidence the various aspects inherent the two possiblesolutions.solutions.

Illustrated representation of Palm section. Illustrated representation of Palm section.

The Dubai’s Palm project for the construction of theartificial islands has estimate the employment of a lot

f t f d th t i d d d f b tt f

The Dubai’s Palm project for the construction of theartificial islands has estimate the employment of a lot

f t f d th t i d d d f b tt fof amounts of sand that is dredged from bottom of seaand was sprayed from dredging ships for realization ofthe artificial structures.

of amounts of sand that is dredged from bottom of seaand was sprayed from dredging ships for realization ofthe artificial structures.

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Naturally this has required besides the problem offinding raw materials, also problems related to thestability erosion and mantenance of the structural

Here we propose to study the possible advantages who results adopting an alternative l ti hi h id th l t f b l t t f d b bl k i d ith

Here we propose to study the possible advantages who results adopting an alternative l ti hi h id th l t f b l t t f d b bl k i d ith

stability, erosion and mantenance of the structuralfeatures of the island.stability, erosion and mantenance of the structuralfeatures of the island.stability, erosion and mantenance of the structuralfeatures of the island.stability, erosion and mantenance of the structuralfeatures of the island.stability, erosion and mantenance of the structuralfeatures of the island.stability, erosion and mantenance of the structuralfeatures of the island.stability, erosion and mantenance of the structuralfeatures of the island.stability, erosion and mantenance of the structuralfeatures of the island.

solution, which provide the employment of a basal stratum formed by blocks mixed with thin material to ensure maximum density, instead of only sand for all structure thickness.solution, which provide the employment of a basal stratum formed by blocks mixed with thin material to ensure maximum density, instead of only sand for all structure thickness.

S L.S L.Pressure bulbPressure bulb

S L. S L.Pressure bulbPressure bulb

S.L.S.L. S.L. S.L.

S.F. S.F. S.F. S.F.

Illustrated representation of Palm section. (Settlements)Illustrated representation of Palm section. (Settlements)- Original plan- Original plan

W = settlement of the basal planeW = settlement of the basal planeS.L.S.L. S.L.W1W1

W2W2

W1W1

W2W2 Pressure bulbPressure bulb

S.L.W0 = settlement of the basal plane W1 = settlement of sand at sea level interfaceW2 = settlement of sand at surface

W0 = settlement of the basal plane W1 = settlement of sand at sea level interfaceW2 = settlement of sand at surface

W = W0 + W1 + W2W = W0 + W1 + W2 W = WconsolidationW = WconsolidationW0W0

S.F.S.F.S.F.

- Alternative plan- Alternative plan The total settlement will be related to the consolidation of sand at various interfaces level

The total settlement will be related to the consolidation of sand at various interfaces level

W0 ≅ 0W0 ≅ 0W = WW = WS.L. S.L.

W2W2W1W1

Pressure bulbPressure bulb

W1 ≅ 0W1 ≅ 0 W = W2W = W2

The total settlement will be limited to the upper level of sand, since than the lower will be has a negligible

The total settlement will be limited to the upper level of sand, since than the lower will be has a negligible

settlement.settlement.

Reclamation baseReclamation base

S.F. S.F.

W0W0

Illustrated representation of Palm section. (Liquefaction and lateral spreading)Illustrated representation of Palm section. (Liquefaction and lateral spreading)and lateral spreading).and lateral spreading).

The phenomenon of liquefaction take greatThe phenomenon of liquefaction take greatimportance where earthquake wavesinteresting deposits of thin saturatedsands with low degree of consolidation. As

th t

importance where earthquake wavesinteresting deposits of thin saturatedsands with low degree of consolidation. As

th tconsequence the porewater pressuresquickly increased, reducing until to cancelthe effective stress and the flowliquefaction occurs

consequence the porewater pressuresquickly increased, reducing until to cancelthe effective stress and the flowliquefaction occurs K bK bliquefaction occurs.liquefaction occurs.

Irregular settlement causes damage until collapse of structures.Irregular settlement causes damage until collapse of structures. Higher urbanisationHigher urbanisation

KobeKobe

ppHigh risk zoneHigh risk zone

Pressure bulbPressure bulb Pressure bulbPressure bulbS.L

.S.L

.Pressure bulbPressure bulb

S.L

.S.L

.

Pressure bulbPressure bulb

Liquefaction can interest the construction for allLiquefaction can interest the construction for all Liquefaction is inhibited for the upper level formedLiquefaction is inhibited for the upper level formed

S.F

.S.F

.S.F

.S.F

.Liquefaction can interest the construction for allthickness giving possible lateral spreadingphenomenons.

Liquefaction can interest the construction for allthickness giving possible lateral spreadingphenomenons.

q ppby sand since that there isn’t a saturated stratumand risk of lateral spreading is also reduced.

q ppby sand since that there isn’t a saturated stratumand risk of lateral spreading is also reduced.

Illustrated representation of Palm section (Erosion).Illustrated representation of Palm section (Erosion).

Another aspect to hold in consideration is theAnother aspect to hold in consideration is theerosion of the island’s boundaries.erosion of the island’s boundaries.

This action mainly operating by mean of the waves and wind, can meaningfull causes regressing of coastal line and than reduce the

idth f b h

This action mainly operating by mean of the waves and wind, can meaningfull causes regressing of coastal line and than reduce the

idth f b hwidth of beach. width of beach.

S.L.S.L.Pressure bulbPressure bulb

S.L. S.L.Pressure bulbPressure bulb

Erosion can involves the entire thi k f dErosion can involves the entire thi k f d

Erosion is limited to the upper layer of Erosion is limited to the upper layer of

S.F. S.F. S.F. S.F.

thickness of sand.thickness of sand. sand.sand.

Illustrated representation of Palm section (Vibrocompaction)Illustrated representation of Palm section (Vibrocompaction)In order to prevent the risk of liquefaction is useful to adopt measures necessary toreduce the liquefaction potential of an area With reference only at geologicalIn order to prevent the risk of liquefaction is useful to adopt measures necessary toreduce the liquefaction potential of an area With reference only at geological

(Vibrocompaction).(Vibrocompaction).

reduce the liquefaction potential of an area. With reference only at geologicalcharacteristics is clear how the deposit’s density affects his susceptibility atliquefaction, since that loose thickening, during an earthquake, favours increase inpore pressure

reduce the liquefaction potential of an area. With reference only at geologicalcharacteristics is clear how the deposit’s density affects his susceptibility atliquefaction, since that loose thickening, during an earthquake, favours increase inpore pressureA method to obtain a mitigation of liquefaction potential is that to use vibrocompaction.A method to obtain a mitigation of liquefaction potential is that to use vibrocompaction.

pore pressure.pore pressure.

S.S. Pressure bulbPressure bulb S.

L

S.

L

Pressure bulbPressure bulb

In this case will be used a verticalIn this case will be used a vertical In this case will be used a horizontal dynamicIn this case will be used a horizontal dynamic

L.

S.

F.

L.

S.

F.S.

F.S.

F.

L. L.

In this case will be used a vertical depth vibrocompaction methodIn this case will be used a vertical depth vibrocompaction method

In this case will be used a horizontal dynamic vibrocompaction method for thicken the superficial sandy level.

In this case will be used a horizontal dynamic vibrocompaction method for thicken the superficial sandy level.