GATE Geomechanics and Ground Control: Geomechanics – Previous Year Questions
28 GATE previous year questions on Geomechanics (Geomechanics and Ground Control, Mining Engineering) with answers and explanations, from every paper.
- GATE 2021 MN Q30 – A coal sample has moisture content 8.0% and bulk unit weight 15.6 kN/m³. Find dry unit weight in kN/m³, to two decimals.
- GATE 2021 MN Q42 – The initial dry-rock Mohr circle has principal stresses σ₃ and σ₁. With full saturation and uniform pore pressure p, which plotted effective-stress…
- GATE 2021 MN Q43 – The failure criterion is σ₁=4σ₃+28 MPa. At A, (σ₃, σ₁)=(10, 90) MPa; at B, (40, 160) MPa. Find safety factors A and B using available…
- GATE 2022 MN Q32 – Water seeps through a vertical sand column of area 4000 mm² and length 300 mm. Applied head is 600 mm and discharge is 100 mm³/min. Find hydraulic…
- GATE 2022 MN Q40 – A 50 mm diameter rock sample fails under 120 kN uniaxial compression on a plane inclined 60° to the horizontal as shown. Find normal and shear…
- GATE 2023 MN Q13 – A shear stress acts tangentially on the top of a block of width w and height h, producing a small top displacement w as shown. Find the engineering…
- GATE 2023 MN Q15 – Two undrained triaxial axial-stress/strain curves for a porous rock are shown. Curve A has pore pressure U = 10 MPa. Which pore pressure best explains…
- GATE 2023 MN Q30 – The Mohr–Coulomb failure envelope in principal stresses is 1=30+3.5 3, with stresses in MPa. Find the failure-plane angle with the σ₃ axis in degrees,…
- GATE 2023 MN Q47 – The circular tunnel shown has vertical far-field stress σ₀ and horizontal stress kσ₀. Boundary point A is on the horizontal radius; B is 45° above it.…
- GATE 2023 MN Q50 – Waves travel through the 100 mm long elastic isotropic cylindrical rock specimen from transmitter A to receiver B. Longitudinal and shear travel times…
- GATE 2023 MN Q51 – A 100 mm high rock specimen with one horizontal joint is loaded vertically at 20 MPa as shown. Rock elastic modulus is 10 GPa and joint normal…
- GATE 2023 MN Q53 – A rock sample of mass 60 g displaces 27 g of brine. Brine specific gravity is 1.05. Find rock unit weight in kN/m³, to two decimals.
- GATE 2024 MN Q22 – For major/minor principal stresses σ₁ and σ₃=−σ₁/2, find maximum shear stress.
- GATE 2024 MN Q31 – A 1000 m³ unconsolidated soil heap has void ratio 1.0. It consolidates to 800 m³ with unchanged solids. Find final void ratio to two decimals.
- GATE 2024 MN Q33 – The 2 m scanline AB crosses the discontinuities shown. With RQD=100(0.1+1)e-0.1 and λ the intersection frequency per metre, find RQD to two decimals.
- GATE 2024 MN Q54 – A rock obeys Mohr–Coulomb τ=7.5+0.84σn in MPa. In triaxial failure with confinement 5 MPa, find shear stress on the failure plane in MPa, to two…
- GATE 2024 MN Q55 – A circular tunnel is 100 m deep under rock of unit weight 27 kN/m³. Tangential stress at horizontal boundary A is 5 MPa. Find tangential stress at…
- GATE 2025 MN Q17 – Principal stresses satisfy τmax =σ₁=−σ₃. What is the normal-stress magnitude on a maximum-shear plane?
- GATE 2025 MN Q18 – In the Brazilian test of a homogeneous rock disc shown, at which point does ideal tensile failure initiate?
- GATE 2025 MN Q28 – Hydraulic fracturing is used in rock with tensile strength6 MPa and minor principal stress8 MPa. Borehole breakdown pressure is10 MPa. Neglect…
- GATE 2025 MN Q31 – Unadjusted roof RMR is64. The joint orientation and tunnel driving direction are shown. For joint dip20°–45°, apply adjustment−2 when driving with dip…
- GATE 2025 MN Q38 – A sandstone specimen in a triaxial test has confining stress10 MPa and axial stress50 MPa. Elastic axial strain is0.0042 and volumetric strain0.0020.…
- GATE 2025 MN Q47 – A pit has5 benches,each8 m high with70° face angle. One bench width is24 m and the other four widths10 m. Find overall slope angle in degrees to two…
- GATE 2025 MN Q51 – Subsidence is s=(S max/2)[1.002-(4.8x/H)]. Here x is measured from the inflection point,negative toward panel centre. Find critical panel-width/depth…
- GATE 2026 MN Q22 – A500 g rock sample retains400 g after the two standard wetting/drying cycles of a slake-durability test. Find the Slake Durability Index in percent.
- GATE 2026 MN Q23 – The graph plots discharge Q against Ah/L for rock samples E,F,G. Here A is cross-sectional area,h the hydraulic head and L sample length. Which…
- GATE 2026 MN Q43 – The flat-jack slots P,Q,R on the gallery wall measure σP,σQ,σR. Slot R is at45° as drawn, σP>σQ and σR=0. Find wall shear stress with the displayed…
- GATE 2026 MN Q65 – A120 Ω strain gauge with gauge factor2.0 is bonded longitudinally to the110 mm rock specimen shown. Resistance-change magnitude at the end of the…