Geotechnical Engineering and Soil Mechanics MCQs 2026

Soil mechanics studies

1. Aonly rock petrology in labs✓
2. Bonly steel fabrication✓
3. Conly highway paint✓
4. Dbehaviour of soil as engineering material under load and water✓

Soil in engineering sense includes

1. Aonly molten magma✓
2. Bunconsolidated mineral particles and organic matter over rock✓
3. Conly cured concrete✓
4. Donly distilled water✓

Three-phase system of soil consists of

1. Aonly solids✓
2. Bonly steel and concrete✓
3. Csolids, water and air✓
4. Donly bitumen✓

Void ratio e is defined as

1. Aweight of water to weight of solids✓
2. Bvolume of solids to total volume✓
3. Cvolume of voids to volume of solids✓
4. Dair content only✓

Porosity n equals

1. Avoid ratio directly✓
2. Bvolume of voids to total volume✓
3. Conly dry density✓
4. Donly liquid limit✓

Degree of saturation Sr is

1. Avolume of water in voids divided by volume of voids✓
2. Balways 100% in field✓
3. Cweight of solids only✓
4. Dplasticity index✓

Water content w is defined as

1. Avolume of voids only✓
2. Btotal mass including water in denominator as wet mass always wrong definition✓
3. Cmass of water to mass of dry soil solids✓
4. Donly air mass✓

Bulk unit weight γ is

1. Adry weight only✓
2. Bsubmerged weight only✓
3. Conly particle density✓
4. Dtotal weight per unit volume including water and air✓

Dry unit weight γd equals

1. Aweight of water only✓
2. Bsaturated submerged unit weight✓
3. Cweight of solids per unit total volume✓
4. Donly void ratio✓

Saturated unit weight γsat applies when

1. Aall voids are filled with water✓
2. Bsoil is oven dry✓
3. Conly air fills voids✓
4. DSr equals zero✓

Submerged unit weight γ' (buoyant) equals

1. Aγsat − γw✓
2. Bγd + γw✓
3. Conly γw✓
4. Dzero always✓

Specific gravity of soil solids Gs is typically about

1. A0.5✓
2. B2.65 to 2.80 for quartz minerals✓
3. C10✓
4. Dequal to void ratio✓

Consistency of fine-grained soil refers to

1. Aonly grain size of gravel✓
2. Bonly permeability in m/s✓
3. Crelative stiffness depending on water content✓
4. Donly colour✓

Liquid limit (LL) is water content at which

1. Asoil passes from plastic to liquid state in standard cup test✓
2. Bsoil becomes solid only✓
3. Cpermeability is zero✓
4. Dvoid ratio is minimum✓

Plastic limit (PL) is water content at which

1. Asoil crumbles at 3 mm threads✓
2. Bsoil flows like water✓
3. Conly sand behaves✓
4. DSr equals 100%✓

Plasticity index PI equals

1. ALL + PL✓
2. BLL/PL only✓
3. CLL − PL✓
4. DPL − LL✓

Soils with PI greater than about 17 are often classified as

1. Aclean gravel only✓
2. Bclayey✓
3. Cnon-plastic silt always✓
4. Drock✓

Shrinkage limit is water content where

1. Asoil becomes liquid✓
2. Bpermeability doubles✓
3. CGs changes✓
4. Dfurther drying causes no decrease in soil volume✓

Unified Soil Classification System (USCS) uses

1. Aonly colour✓
2. Bonly slump of concrete✓
3. Cgrain size and Atterberg limits for symbol (e.g., SM, CL)✓
4. Donly steel grade✓

Angle of internal friction φ can be found from

1. Aonly liquid limit✓
2. Bdirect shear or triaxial test on sample✓
3. Conly Proctor✓
4. Donly slump✓

Unconfined compression test gives

1. Aundrained shear strength for cohesive soil su = qu/2✓
2. Bφ for gravel✓
3. Cpermeability k✓
4. DGs only✓

Triaxial test applies

1. Aonly torsion on steel✓
2. Bonly impact on aggregate✓
3. Caxial load while controlling confining pressure and drainage✓
4. Donly Vicat✓

Direct shear test shears soil along

1. Apredetermined horizontal plane✓
2. Bvertical plane only in rock✓
3. Crandom fracture✓
4. Donly at LL✓

Sensitivity of clay is ratio of

1. ALL to PL✓
2. Bundisturbed to remoulded strength✓
3. CCu to Cc✓
4. Dk wet to k dry✓

Bearing capacity is

1. Aonly settlement always elastic✓
2. Bonly permeability limit✓
3. Conly capillary rise✓
4. Dmaximum pressure foundation soil can support without shear failure✓

Terzaghi general bearing capacity equation for strip footing includes terms

1. Acohesion, surcharge and soil weight contributions✓
2. Bonly water colour✓
3. Conly timber moisture✓
4. Donly paint viscosity✓

Shallow foundation depth is generally

1. Aalways more than 10 m✓
2. Bless than twice the footing width✓
3. Conly pile tip✓
4. Dzero embedment always✓

Deep foundation extends

1. Adeep below surface to competent strata or develops skin friction✓
2. Bonly 10 cm depth✓
3. Conly on pure rock always at surface✓
4. Dwithout any load✓

Lateral earth pressure on retaining wall depends on

1. Asoil type, wall movement and drainage✓
2. Bonly wall paint✓
3. Conly concrete grade alone✓
4. Donly wind on roof✓

Active earth pressure coefficient Ka applies when

1. Awall is rigid without movement✓
2. Bwall pushes into soil✓
3. Csoil is liquid✓
4. Dwall moves away from soil allowing failure wedge expansion✓

Passive earth pressure develops when

1. Awall recedes from backfill✓
2. Bno friction on wall✓
3. Csoil is dry gravel only✓
4. Dwall moves toward soil compressing it✓

At-rest earth pressure K0 is appropriate when

1. Alarge outward displacement occurs✓
2. Bfull passive state develops✓
3. Csoil is submerged only✓
4. Dwall is rigid and soil cannot yield laterally✓

Slope stability analysis evaluates

1. Afactor of safety against sliding along potential slip surface✓
2. Bonly bearing capacity of footing✓
3. Conly capillary rise✓
4. Donly paint drying✓

Factor of safety less than 1 in slope analysis means

1. Aunstable — driving exceeds resisting✓
2. Bover-designed✓
3. Conly elastic settlement✓
4. Dpermeability too low✓

Seepage through earth dam is controlled by

1. Aonly steep downstream face without drainage✓
2. Bzero compaction✓
3. Cfilters, drains and core impermeability✓
4. Donly paint seal✓

Piping failure in embankment is caused by

1. Aerosion of fine particles along seepage path✓
2. Bonly external wind✓
3. Conly LL test✓
4. Donly high φ✓

Frost heave in soils is most problematic in

1. Aclean gravel below water table✓
2. Brock only✓
3. Csilts with capillary action and freezing front✓
4. Ddry sand in desert✓

Expansive soils contain

1. Aonly quartz gravel✓
2. Bzero plasticity✓
3. Cno volume change✓
4. Dclay minerals (e.g., montmorillonite) that swell on wetting✓

Stabilization of soil with lime is effective for

1. Aclean uniform gravel only✓
2. Bplastic clays reducing PI and increasing workability✓
3. Conly organic peat without treatment✓
4. Donly steel✓

Geotextile in roads primarily provides

1. Aonly decoration✓
2. Bzero drainage ever✓
3. Cseparation, filtration and reinforcement functions✓
4. Dreplacement of all fill✓

Standard penetration test (SPT) N-value indicates

1. Ablows per foot for 30 cm penetration after seating blows✓
2. Bliquid limit✓
3. Cconcrete slump✓
4. Dsteel yield✓

SPT is performed using

1. Aonly hand auger without blows✓
2. Bonly GPS✓
3. Conly plate load on surface always✓
4. Dsplit-spoon sampler driven by hammer in borehole✓

Cone penetration test (CPT) measures

1. Aonly LL and PL✓
2. Bcone resistance and sleeve friction continuously with depth✓
3. Conly timber grade✓
4. Donly bitumen penetration on road✓

Plate load test on soil determines

1. Aonly Atterberg limits✓
2. Bonly wind speed✓
3. Conly chloride in concrete✓
4. Dmodulus of subgrade reaction and bearing characteristics✓

Well-graded soil (GW or SW) has

1. Auniform single size only✓
2. Bno fines at all always✓
3. CPI above 50✓
4. Dgood representation of many particle sizes✓

Coefficient of uniformity Cu is

1. AD10/D60✓
2. BD60/D10✓
3. CLL/PL✓
4. De/n✓

Coefficient of curvature Cc is

1. AD60/D10✓
2. BD30² / (D10 × D60)✓
3. CPI only✓
4. Dvoid ratio✓

Relative density Dr indicates

1. Adegree of compaction of cohesionless soil✓
2. Bplasticity of clay✓
3. Cliquid limit✓
4. Donly moisture in timber✓

Standard Proctor test compacts soil at

1. Aonly undrained triaxial✓
2. Bonly liquid limit✓
3. Cdefined moisture and energy to find maximum dry density✓
4. Donly slump✓

Modified Proctor uses

1. Ahigher compaction energy than Standard Proctor✓
2. Bless blows✓
3. Cno moisture control✓
4. Donly rock cores✓

Optimum moisture content (OMC) is

1. Amoisture at maximum dry unit weight for given compactive effort✓
2. Balways zero✓
3. Calways equal to LL✓
4. Dminimum dry density point✓

Zero air voids line on compaction plot represents

1. Aminimum possible density✓
2. Btheoretical maximum density for given water content✓
3. Cliquid limit line✓
4. Dpermeability contour✓

Field compaction control often uses

1. Aonly Vicat needle✓
2. Bsand cone or nuclear density gauge on test strips✓
3. Conly rebound hammer on concrete✓
4. Donly compass✓

Permeability of soil is

1. Ashear strength only✓
2. Bplastic limit✓
3. Ccolour index✓
4. Dease with which water flows through pore spaces✓

Darcy law states discharge velocity is proportional to

1. Ashear stress only✓
2. Bhydraulic gradient✓
3. Cplasticity index✓
4. DLL✓

Coefficient of permeability k has units

1. AkN/m²✓
2. Bdegrees✓
3. Cpercent✓
4. Dm/s or cm/s✓

Constant head permeability test is suited for

1. Alow permeability clays✓
2. Bonly rock without fractures✓
3. Ccoarse-grained soils with high k✓
4. Donly dry sand✓

Falling head test is used for

1. Agravel only✓
2. Bfine-grained soils with low permeability✓
3. Csteel plates✓
4. Donly air✓

Capillary rise in fine soils occurs because of

1. Asurface tension in water meniscus in small pores✓
2. Bonly gravity drainage✓
3. Conly plastic limit✓
4. Donly compaction energy✓

Effective stress principle states strength and deformation depend on

1. Atotal stress only✓
2. Beffective normal stress (total stress minus pore water pressure)✓
3. Cair pressure only✓
4. Dcolour of soil✓

Pore water pressure increases with

1. Aonly drying✓
2. Bonly LL decrease✓
3. Conly gravel size✓
4. Ddepth below water table in static conditions✓

Quick condition (boiling) in sand occurs when

1. Aupward seepage gradient reduces effective stress to zero✓
2. Bsoil is over-compacted✓
3. Conly clay present✓
4. DLL is high✓

Consolidation is

1. Ainstant elastic only in all soils✓
2. Bonly crushing of gravel✓
3. Ctime-dependent volume reduction under sustained load as water expels✓
4. Donly chemical set like cement✓

Terzaghi one-dimensional consolidation assumes

1. Afully drained instantaneously✓
2. Bonly dry sand✓
3. Crigid rock✓
4. Dsoil laterally confined and saturated✓

Compression index Cc from e-log σ curve indicates

1. Aslope of virgin compression line for normally consolidated clay✓
2. Bpermeability✓
3. Cangle of friction only✓
4. DLL directly✓

Coefficient of consolidation Cv controls

1. Aonly ultimate settlement magnitude only without time✓
2. Bonly angle of internal friction✓
3. Crate of consolidation settlement✓
4. Donly Dr✓

Soil mechanics studies

1. Aonly rock petrology in labs✓
2. Bonly steel fabrication✓
3. Conly highway paint✓
4. Dbehaviour of soil as engineering material under load and water✓

Soil in engineering sense includes

1. Aonly molten magma✓
2. Bunconsolidated mineral particles and organic matter over rock✓
3. Conly cured concrete✓
4. Donly distilled water✓

Three-phase system of soil consists of

1. Aonly solids✓
2. Bonly steel and concrete✓
3. Csolids, water and air✓
4. Donly bitumen✓

Void ratio e is defined as

1. Aweight of water to weight of solids✓
2. Bvolume of solids to total volume✓
3. Cvolume of voids to volume of solids✓
4. Dair content only✓

Porosity n equals

1. Avoid ratio directly✓
2. Bvolume of voids to total volume✓
3. Conly dry density✓
4. Donly liquid limit✓

Degree of saturation Sr is

1. Avolume of water in voids divided by volume of voids✓
2. Balways 100% in field✓
3. Cweight of solids only✓
4. Dplasticity index✓

Water content w is defined as

1. Avolume of voids only✓
2. Btotal mass including water in denominator as wet mass always wrong definition✓
3. Cmass of water to mass of dry soil solids✓
4. Donly air mass✓

Bulk unit weight γ is

1. Adry weight only✓
2. Bsubmerged weight only✓
3. Conly particle density✓
4. Dtotal weight per unit volume including water and air✓

Dry unit weight γd equals

1. Aweight of water only✓
2. Bsaturated submerged unit weight✓
3. Cweight of solids per unit total volume✓
4. Donly void ratio✓

Saturated unit weight γsat applies when

1. Aall voids are filled with water✓
2. Bsoil is oven dry✓
3. Conly air fills voids✓
4. DSr equals zero✓

Submerged unit weight γ' (buoyant) equals

1. Aγsat − γw✓
2. Bγd + γw✓
3. Conly γw✓
4. Dzero always✓

Specific gravity of soil solids Gs is typically about

1. A0.5✓
2. B2.65 to 2.80 for quartz minerals✓
3. C10✓
4. Dequal to void ratio✓

Consistency of fine-grained soil refers to

1. Aonly grain size of gravel✓
2. Bonly permeability in m/s✓
3. Crelative stiffness depending on water content✓
4. Donly colour✓

Liquid limit (LL) is water content at which

1. Asoil passes from plastic to liquid state in standard cup test✓
2. Bsoil becomes solid only✓
3. Cpermeability is zero✓
4. Dvoid ratio is minimum✓

Plastic limit (PL) is water content at which

1. Asoil crumbles at 3 mm threads✓
2. Bsoil flows like water✓
3. Conly sand behaves✓
4. DSr equals 100%✓

Plasticity index PI equals

1. ALL + PL✓
2. BLL/PL only✓
3. CLL − PL✓
4. DPL − LL✓

Soils with PI greater than about 17 are often classified as

1. Aclean gravel only✓
2. Bclayey✓
3. Cnon-plastic silt always✓
4. Drock✓

Shrinkage limit is water content where

1. Asoil becomes liquid✓
2. Bpermeability doubles✓
3. CGs changes✓
4. Dfurther drying causes no decrease in soil volume✓

Unified Soil Classification System (USCS) uses

1. Aonly colour✓
2. Bonly slump of concrete✓
3. Cgrain size and Atterberg limits for symbol (e.g., SM, CL)✓
4. Donly steel grade✓

Angle of internal friction φ can be found from

1. Aonly liquid limit✓
2. Bdirect shear or triaxial test on sample✓
3. Conly Proctor✓
4. Donly slump✓

Unconfined compression test gives

1. Aundrained shear strength for cohesive soil su = qu/2✓
2. Bφ for gravel✓
3. Cpermeability k✓
4. DGs only✓

Triaxial test applies

1. Aonly torsion on steel✓
2. Bonly impact on aggregate✓
3. Caxial load while controlling confining pressure and drainage✓
4. Donly Vicat✓

Direct shear test shears soil along

1. Apredetermined horizontal plane✓
2. Bvertical plane only in rock✓
3. Crandom fracture✓
4. Donly at LL✓

Sensitivity of clay is ratio of

1. ALL to PL✓
2. Bundisturbed to remoulded strength✓
3. CCu to Cc✓
4. Dk wet to k dry✓

Bearing capacity is

1. Aonly settlement always elastic✓
2. Bonly permeability limit✓
3. Conly capillary rise✓
4. Dmaximum pressure foundation soil can support without shear failure✓

Terzaghi general bearing capacity equation for strip footing includes terms

1. Acohesion, surcharge and soil weight contributions✓
2. Bonly water colour✓
3. Conly timber moisture✓
4. Donly paint viscosity✓

Shallow foundation depth is generally

1. Aalways more than 10 m✓
2. Bless than twice the footing width✓
3. Conly pile tip✓
4. Dzero embedment always✓

Deep foundation extends

1. Adeep below surface to competent strata or develops skin friction✓
2. Bonly 10 cm depth✓
3. Conly on pure rock always at surface✓
4. Dwithout any load✓

Lateral earth pressure on retaining wall depends on

1. Asoil type, wall movement and drainage✓
2. Bonly wall paint✓
3. Conly concrete grade alone✓
4. Donly wind on roof✓

Active earth pressure coefficient Ka applies when

1. Awall is rigid without movement✓
2. Bwall pushes into soil✓
3. Csoil is liquid✓
4. Dwall moves away from soil allowing failure wedge expansion✓

Passive earth pressure develops when

1. Awall recedes from backfill✓
2. Bno friction on wall✓
3. Csoil is dry gravel only✓
4. Dwall moves toward soil compressing it✓

At-rest earth pressure K0 is appropriate when

1. Alarge outward displacement occurs✓
2. Bfull passive state develops✓
3. Csoil is submerged only✓
4. Dwall is rigid and soil cannot yield laterally✓

Slope stability analysis evaluates

1. Afactor of safety against sliding along potential slip surface✓
2. Bonly bearing capacity of footing✓
3. Conly capillary rise✓
4. Donly paint drying✓

Factor of safety less than 1 in slope analysis means

1. Aunstable — driving exceeds resisting✓
2. Bover-designed✓
3. Conly elastic settlement✓
4. Dpermeability too low✓

Seepage through earth dam is controlled by

1. Aonly steep downstream face without drainage✓
2. Bzero compaction✓
3. Cfilters, drains and core impermeability✓
4. Donly paint seal✓

Piping failure in embankment is caused by

1. Aerosion of fine particles along seepage path✓
2. Bonly external wind✓
3. Conly LL test✓
4. Donly high φ✓

Frost heave in soils is most problematic in

1. Aclean gravel below water table✓
2. Brock only✓
3. Csilts with capillary action and freezing front✓
4. Ddry sand in desert✓

Expansive soils contain

1. Aonly quartz gravel✓
2. Bzero plasticity✓
3. Cno volume change✓
4. Dclay minerals (e.g., montmorillonite) that swell on wetting✓

Stabilization of soil with lime is effective for

1. Aclean uniform gravel only✓
2. Bplastic clays reducing PI and increasing workability✓
3. Conly organic peat without treatment✓
4. Donly steel✓

Geotextile in roads primarily provides

1. Aonly decoration✓
2. Bzero drainage ever✓
3. Cseparation, filtration and reinforcement functions✓
4. Dreplacement of all fill✓

Standard penetration test (SPT) N-value indicates

1. Ablows per foot for 30 cm penetration after seating blows✓
2. Bliquid limit✓
3. Cconcrete slump✓
4. Dsteel yield✓

SPT is performed using

1. Aonly hand auger without blows✓
2. Bonly GPS✓
3. Conly plate load on surface always✓
4. Dsplit-spoon sampler driven by hammer in borehole✓

Cone penetration test (CPT) measures

1. Aonly LL and PL✓
2. Bcone resistance and sleeve friction continuously with depth✓
3. Conly timber grade✓
4. Donly bitumen penetration on road✓

Plate load test on soil determines

1. Aonly Atterberg limits✓
2. Bonly wind speed✓
3. Conly chloride in concrete✓
4. Dmodulus of subgrade reaction and bearing characteristics✓