Earthquake Engineering Structural Testing Foundation Test Civil Engineering Notes Building Safety Seismic Design
Dynamic Vibration Test (Most common method)
Ye test kab karte hain?
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Multistorey building
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Earthquake resistance check
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Base / foundation behavior dekhne ke liye
Kya-kya chahiye?
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Vibration machine (shaker)
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Accelerometer sensors
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Data recorder / laptop
Kaise perform karte hain? (Step-by-step)
1️⃣ Building ke base + har floor par sensors lagate hain
2️⃣ Base ya kisi floor par vibration machine fix karte hain
3️⃣ Machine se controlled vibration dete hain
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Pehle slow
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Phir thoda fast
4️⃣ Building thodi si hilti hai (safe limit me)
5️⃣ Sensors vibration record karte hain
📊 Kya check hota hai?
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Natural time period
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Damping
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Mode shape
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Base movement zyada hai ya kam
🧠 Result ka matlab
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Zyada vibration → base weak ⚠️
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Uniform vibration → foundation OK ✅
2️⃣ Forced Vibration Test (Building ko jaan-bujh kar hilaana)
👉 Ye “hila-kar test” ka sabse clear example hai
⚙️ Kaise karte hain?
1️⃣ Heavy rotating machine building ke base ya roof par lagate hain
2️⃣ Machine ghoomti hai → vibration create hoti hai
3️⃣ Speed badhate jaate hain
4️⃣ Building response note karte hain
📊 Kya dekhte hain?
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Resonance aata hai ya nahi
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Base displacement kitna hai
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Cracks develop ho rahe hain ya nahi
3️⃣ Ambient Vibration Test (Natural hilaav)
👷 Ye test kaise hota hai?
Isme building ko jaan-bujh kar nahi hilate
⚙️ Process:
1️⃣ Sensors lagate hain
2️⃣ Wind, traffic, log chalne se jo halka hilaav hota hai
3️⃣ Usko record karte hain
👉 Fayda:
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Safe
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Existing buildings ke liye best
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Base stiffness ka idea milta hai
4️⃣ Shake Table Test (Lab level)
⚠️ Ye real building par nahi hota
⚙️ Kaise?
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Building ka model banate hain
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Table par rakhkar earthquake jaisa hilaate hain
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Foundation behavior observe karte hain
5️⃣ Simple Site-Level Base Check (Without machine)
Agar test machine available nahi hai 👇
🔹 Visual + Instrument check
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Base par settlement
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Plinth beam cracks
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Uneven gaps
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Water seepage
🔹 Level instrument se
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Column verticality
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Differential settlement
🧠 Exam ke liye short answer (yaad rakhna)
“Building ke base par vibration check karne ke liye
Dynamic vibration test / forced vibration test kiya jaata hai
jisme controlled vibration dekar foundation response observe kiya jaata hai.”
Important baat (samajh lo)
❌ Building ko manually hilaana dangerous
❌ JCB se dhakka dena galat
✅ Sirf instrumented vibration test safe & correct
SOIL TESTS (Foundation se pehle)
1. Standard Penetration Test (SPT)
Kaun karta hai?
Geotechnical engineer + drilling team
Kya chahiye?
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Bore machine
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63.5 kg hammer
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Split spoon sampler
Kaise karte hain?
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Zameen me bore hole banate hain
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Sampler ko hole me rakhte hain
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Hammer ko 760 mm upar se girate hain
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15-15 cm ke 3 parts me count karte hain
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Last 30 cm ke blows = N-value
Result ka matlab:
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N < 10 → Mitti kamzor ❌
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N = 10–30 → Medium 👍
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N > 30 → Strong soil 💪
🔹 2. Liquefaction Test
👷 Kaun karta hai?
Soil lab + geotech engineer
⚙️ Kaise karte hain?
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SPT data lete hain
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Water table depth note karte hain
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Earthquake zone & magnitude apply karte hain
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Formula se check karte hain:
👉 Liquefaction hoga ya nahi
⚠️ Agar liquefaction mile?
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Pile foundation
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Soil improvement (compaction / grouting)
🔹 3. Plate Load Test
🧰 Kya chahiye?
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Steel plate
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Hydraulic jack
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Dial gauge
⚙️ Kaise karte hain?
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Ground ko level karte hain
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Plate rakhte hain
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Upar se load lagate hain
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Settlement measure karte hain
📊 Result:
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Zyada settlement = weak soil
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Kam settlement = safe foundation
2️⃣ STRUCTURAL ANALYSIS (Design stage)
(Ye site par nahi, computer/software me hota hai)
🔹 4. Equivalent Static Analysis
⚙️ Kaise karte hain?
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Building ka weight calculate
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Earthquake zone decide
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Horizontal force apply
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Beam-column check
👉 Simple meaning:
Earthquake ko dhakka maan ke design
🔹 5. Response Spectrum Analysis ⭐⭐⭐
⚙️ Kaise karte hain?
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Building ka 3D model banao
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Software me response spectrum curve daalo
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Run karo analysis
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Story drift, shear check karo
👉 Kya pata chalta?
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Kaunsa floor zyada hilta hai
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Weak point kaha hai
🔹 6. Time History Analysis
⚙️ Kaise karte hain?
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Real earthquake record lo
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Time vs ground motion daalo
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Building ka reaction dekho
3️⃣ CONCRETE TESTS (Construction ke time)
🔹 7. Slump Test
🧰 Kya chahiye?
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Slump cone
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Tamping rod
⚙️ Kaise karte hain?
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Cone ko bharo (3 layers)
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Har layer me 25 rod
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Cone upar uthao
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Jo height giri = slump
📊 Result:
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75–100 mm = best 👍
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Bahut zyada = weak concrete ❌
🔹 8. Concrete Cube Test
🧰 Kya chahiye?
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Cube mould
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CTM machine
⚙️ Kaise karte hain?
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Fresh concrete cube me bharo
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24 ghante baad paani me daalo
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7 & 28 din baad machine me test
📊 Result:
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Strength ≥ design value = OK
4️⃣ STEEL TESTS
🔹 9. Tensile Test
⚙️ Kaise karte hain?
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Steel bar ko machine me lagao
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Slowly kheecho
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Break hone tak load badhao
📊 Result:
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Yield strength
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Ductility
🔹 10. Bend / Re-bend Test
⚙️ Kaise?
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Steel ko bend karo
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Wapas seedha karo
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Crack nahi aana chahiye
5️⃣ STRUCTURAL MEMBER TEST
🔹 11. Column Load Test
⚙️ Kaise?
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Column par hydraulic jack
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Load lagate jao
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Crack / deformation dekho
🔹 12. Beam Deflection Test
⚙️ Kaise?
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Beam ke niche dial gauge
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Load lagao
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Deflection measure karo
6️⃣ NON-DESTRUCTIVE TEST (Building todhe bina)
🔹 13. Rebound Hammer Test
⚙️ Kaise?
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Hammer se concrete par hit
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Number note karo
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Chart se strength pata karo
🔹 14. UPV Test
⚙️ Kaise?
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Transmitter & receiver lagao
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Pulse bhejo
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Time measure karo
Result:
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Fast speed = strong concrete
🔹 15. Cover Meter Test
⚙️ Kaise?
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Machine concrete par rakho
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Steel location & cover dikhega
🔚 FINAL BAAT (Earthquake Safety Mantra)
✔ Pehle soil strong karo
✔ Proper analysis karo
✔ Ductile detailing follow karo
✔ Quality material use karo
✔ Test report ignore mat karo
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