CELE Structural Theory & Analysis — Loads and Load Combinations (NSCP)Memory Anchors

Memory aid

Use the phrase 'DALWERS' for the 7 LRFD combos in order: D-only (1.4D), A-ll gravity (1.2D+1.6L), L-r roof governs, W-ind enters, E-arthquake, R-educed D with wind, R-educed D with seismic. Visualize a DALWERS (like 'dollars') coin machine: you feed in your loads and it spits out the governing factored force.

Why it works

Acronyms collapse a 7-item list into a single memorable word. The coin machine image adds a visual-action memory layer, and the dollar/DALWERS sound is culturally familiar to Filipino reviewees who think in both USD and PHP.

Example usage

Exam question: 'How many LRFD load combinations does NSCP prescribe for basic building loads?' Recall DALWERS → count 7 letters → answer: 7 combinations.

Recall trigger

Think: 'How many pesos (DALWERS) does this structure cost in load combinations?' → 7 combos

Memory aid

Imagine a 'lagpas-oras' (overtime) worker who only does dead-load tasks. His manager (the code) gives him a 40% bonus (×1.4) for working alone with no help from live or wind loads. 1.4 = 1 + 0.4 → 'one full shift plus 40% overtime.' This combo governs only when dead load dominates — like a massive concrete dam with negligible occupancy.

Why it works

The overtime worker analogy maps the factor 1.4 to a familiar Filipino workplace concept (overtime pay). It also conveys WHY the factor exists: because dead load alone, without live load reduction, still needs amplification for safety.

Example usage

When asked for the simplest LRFD combo, recall the lonely overtime worker → 1.4D. Check if it governs by comparing to 1.2D+1.6L for the given problem.

Recall trigger

Think: 'Overtime worker, 40% bonus, working alone' → 1.4D

Memory aid

Chant this every morning of your review: 'One-point-two D, one-point-six L, add half the roof or rain — this combo rules them all, a gravity hurricane!' The '1.2' and '1.6' are the two magic numbers. Note: 1.2 < 1.6 because dead load is more predictable than live load, so live gets the bigger hammer.

Why it works

Rhymes exploit the brain's phonological loop, making the sequence replay automatically. The phrase 'gravity hurricane' creates a dramatic visual — imagine a storm of furniture and people loading a floor slab.

Example usage

Board problem: find factored UDL for a floor beam. Immediately chant the rhyme → write 1.2D + 1.6L + 0.5Lr → plug in numbers.

Recall trigger

Hear the chant: '1.2 D, 1.6 L, half the roof...' → Combo 2, gravity governs

Memory aid

Story: Engineer Mang Toni designs a lightweight roof in Pampanga. During typhoon season, the wind tries to LIFT the roof off. Mang Toni realizes: 'Ang dead load ay nagtatambal sa wind — pero hindi ko maaaring i-assume ang buong dead load! Baka mas maliit ito sa field.' So NSCP forces him to use only 90% of dead load (0.9D) — the conservative minimum — to represent the WORST CASE where dead load can't fully resist uplift. If he used 1.2D, dead load would seem to help more, and the structure might APPEAR safe when it's not. 0.9D is the 'pessimistic dead load' scenario.

Why it works

The story personalizes the abstract idea of WHY 0.9D is used. Filipino students relate to Pampanga typhoons and the concept of a roof being blown away. The story encodes the logic, not just the number — so students can reconstruct the formula even if they forget it.

Example usage

Question: 'A light steel canopy is checked for uplift. Which LRFD combo applies?' Recall Mang Toni's roof → 0.9D + 1.0W (Combo 6) or 0.9D + 1.0E (Combo 7). Choose based on whether wind or earthquake governs.

Recall trigger

Think: 'Mang Toni's roof being lifted in typhoon' → 0.9D + 1.0W (uplift combo)

Memory aid

ASD is like a 'tindahan' (sari-sari store) using real prices — no discounts, no markups. You just add what you have: Dead load + Live load = total service load. No factors needed. Compare this to LRFD which is like a 'Robinsons supermart' with loyalty points (factors) that multiply your bill. ASD combo 2 is simply D + L — what you see is what you get.

Why it works

Contrasting ASD (tindahan, plain prices) with LRFD (supermart with multipliers) gives students a mental model for choosing the right philosophy. Filipino students universally understand both sari-sari store and SM/Robinsons shopping contexts.

Example usage

Problem says 'service-load design' or 'allowable stress' → use ASD combos. First check D + L (Combo 2), then check combos with wind/seismic.

Recall trigger

Think: 'sari-sari store, plain prices' → ASD, no factors, D + L

Memory aid

Remember '6-6-7': ASD uplift uses 0.6D + 0.6W or 0.6D + 0.7E. The pattern: 'Six-Six-Seven: Six on D, Six on Wind, Seven on Earthquake.' Why 0.7E instead of 0.6E? Because earthquake is more dangerous and less predictable than wind, so the seismic companion factor is slightly larger. Think: '7 = earthquake gets one extra point for danger.'

Why it works

Number chunking (6-6-7) is easier to remember than three separate decimals. The 'danger point for earthquake' rationale embeds the logic so students can reconstruct the pattern.

Example usage

ASD problem with wind uplift on a roof → recall 6-6-7 → 0.6D + 0.6W. ASD with earthquake → 0.6D + 0.7E.

Recall trigger

Chant '6-6-7' → 0.6D + 0.6W or 0.6D + 0.7E (ASD uplift combos)

Memory aid

Visualize a jeepney terminal parking lot divided into loading bays. An INTERIOR bay takes passengers from BOTH sides (full spacing s on each side → total tributary width = s). An EDGE bay only loads from ONE side (half spacing = s/2 tributary width). Now imagine load as passengers: interior beams get twice as many passengers as edge beams per meter of span. Draw this parking-bay image in your mind during the exam.

Why it works

Visual-spatial memory is highly durable. The jeepney terminal is a quintessentially Filipino scene that makes the abstract geometry of tributary areas concrete and immediately pictureable.

Example usage

Problem: 'Beam B2 is at the edge of a bay, beams spaced 3 m apart. Find tributary width.' Recall the edge bay → tributary width = 3/2 = 1.5 m (not 3 m).

Recall trigger

Picture the jeepney terminal parking bays → interior = full s, edge = half s

Memory aid

Think of a banana plantation. The area load q (kPa = kN/m²) is the weight of bananas PER SQUARE METER of field. Your beam is like a harvest row of width s (meters). The harvester walks along the beam and collects all bananas within width s — so total bananas per meter of beam = q × s = w (kN/m). The beam only 'sees' a strip of the field, not the entire farm.

Why it works

The banana farm analogy makes the dimensional reasoning (kN/m² × m = kN/m) physically intuitive. Filipino students in regions with agricultural backgrounds will immediately grasp the 'strip of field' concept.

Example usage

slab q_D = 4 kPa, beam spacing s = 3 m → w_D = 4 × 3 = 12 kN/m. Always multiply area load by spacing to get line load.

Recall trigger

Banana harvest row of width s → w = q × s

Memory aid

Story: Ate Sarah manages a 6×6 m2 food stall in Divisoria. Every kPa of crowd pressure (kN/m²) acts over her entire 36 m² stall area. At the end of the day, the total load on her support column is P = q × A_t = crowd pressure × stall area. She tells her column: 'You carry the WHOLE AREA, not just a strip!' Unlike a beam (which carries a strip), the column must carry the FULL tributary rectangle.

Why it works

Contrasting Ate Sarah's column (full area) with the banana farm beam (strip) reinforces the distinction between P = qA_t (column) and w = qs (beam). The Divisoria setting is familiar and vivid for Metro Manila students.

Example usage

Interior column, tributary 5 m × 5 m = 25 m², q = 6 kPa → P = 6 × 25 = 150 kN. Always use full tributary area for columns.

Recall trigger

Ate Sarah's food stall column in Divisoria → P = q × A_t

Memory aid

Dead load is the 'patay na timbang' (dead weight) — it never moves, never changes. Visualize a TOMBSTONE (dead → permanent). The tombstone has a fixed weight: concrete slab, steel beam, roofing tiles — all predictable from density × volume. The tombstone never gets up. Associate every dead load item with a tombstone in your mind: slab (tombstone), beams (tombstone), DL finishes (tombstone).

Why it works

The tombstone visual is morbidly memorable (morbid images stick in memory) and linguistically reinforces the English word 'dead' load. It also reinforces the key attribute: permanence.

Example usage

Exam: 'Classify: weight of concrete slab.' Recall tombstone → Dead load (D). Distinguish from live load which moves/changes.

Recall trigger

Tombstone → Dead load → permanent, predictable, self-weight

Memory aid

Live load is the 'buhay na tao' (living people) on the structure — they move, they come and go. Imagine a fiesta in your barangay: sometimes 500 people pack the covered court (high live load), sometimes it's empty (zero live load). The code gives MINIMUM live loads by occupancy: residential = 1.9 kPa (about 190 kg/m² — a crowd of people standing close). Remember: Live = Variable = People and their stuff.

Why it works

The barangay fiesta image is culturally resonant for Filipino students and captures the variability of live load beautifully. The contrast (500 people vs empty) makes the uncertainty of live loads concrete.

Example usage

Problem: 'Minimum live load for a classroom floor per NSCP?' Live load → occupancy table → 1.9–2.9 kPa for classrooms.

Recall trigger

Barangay fiesta covered court → Live load, variable, occupancy-dependent

Memory aid

Story: The 1990 Luzon earthquake (M7.8) collapsed hundreds of buildings because engineers underestimated seismic forces. After that, every Filipino engineer knows: 'Sa Pilipinas, si E ang BOSS ng lateral loads.' (In the Philippines, E is the BOSS of lateral loads.) The Philippines sits on the Pacific Ring of Fire — we have more earthquakes than most countries. So when you see a lateral design problem, ask E first before W. E = Boss. W = second in command.

Why it works

Anchoring the code requirement to a real Philippine historical event (1990 Luzon earthquake) makes it emotionally significant and contextually memorable. Students understand WHY E governs, not just that it does.

Example usage

Problem: 'Design a lateral-force resisting frame for a building in Manila.' Think E is boss → check NSCP seismic provisions → E likely governs over W in most Philippine locations.

Recall trigger

1990 Luzon earthquake → E is boss of lateral design in PH

Memory aid

LRFD and ASD are like two methods of paying your jeepney fare: LRFD = 'Boundary system' (driver gets a fixed quota/boundary; loads are multiplied UP to get the target, then compared to φ×capacity). ASD = 'Pasahero system' (you pay per passenger/service; actual service load compared to capacity/safety-factor, no multipliers on loads). Key rule: NEVER mix the two systems — don't use LRFD factored loads with ASD allowable stress, just as you can't mix boundary and per-passenger payments in the same jeepney.

Why it works

The jeepney analogy uses a transport system that every Filipino understands intuitively. The warning about mixing systems is embedded in the story logic (you can't mix payment systems), helping students avoid the #1 board-exam pitfall.

Example usage

Problem says 'LRFD design' → multiply loads by NSCP factors → compare to φ×Mn. Problem says 'ASD' → use service loads → compare to Mn/Ω. Never cross the streams.

Recall trigger

Jeepney: Boundary = LRFD (factors loads up), Pasahero = ASD (service loads, divide by FS)

Memory aid

Remember 'Three-Quarter Club': when WIND joins the ASD party, everything gets a 75% discount (×0.75) except the base dead load D. So: D stays full, but L gets 75%, Lr/R gets 75%, and even the wind factor (0.6W) gets the 75% treatment. Chant: 'D stays, rest pays 75.' Also note: W already has a built-in factor of 0.6 in ASD — so wind in ASD = 0.6W, then multiplied by 0.75 when combined = 0.45W effective.

Why it works

The '75% discount club' creates a shopping analogy (deeply resonant for Filipino students who love sales) and accurately captures the load-reduction logic of combining multiple variable loads.

Example usage

ASD problem with D, L, Lr, and W: write D + 0.75L + 0.75(0.6W) + 0.75(Lr). Compute and compare to other ASD combos.

Recall trigger

'Three-Quarter Club' discount sale → ASD wind combo, 0.75 on L, Lr, and 0.6W

Memory aid

Visualize two workers on a roof: Worker 'Raul' (R = rain) brings a bucket filling with rainwater (rain ponding), and worker 'Larry Roof' (Lr = roof live load) carries maintenance tools. Both are TEMPORARY loads on the roof, NOT the same as the floor live load L. In LRFD combos, Lr and R appear in parentheses '(Lr or R)' — like choosing between Raul and Larry. They are alternatives; use whichever is larger.

Why it works

Personifying Lr and R as named workers on a roof makes the distinction between roof-specific loads and floor live load (L) concrete and visual. The 'choose the heavier worker' image captures the 'larger of Lr or R' design intent.

Example usage

Problem gives both Lr = 1.0 kPa and R = 0.5 kPa → use Lr = 1.0 kPa (larger). In the LRFD combo, substitute (Lr or R) with 1.0 kPa.

Recall trigger

Workers Raul (R) and Larry Roof (Lr) on the rooftop → roof loads, choose the larger one

Memory aid

Remember 'APG = 1.0': Assembly areas, Parking garages, and Garages-with-heavy-load (L > 4.8 kPa) use f1 = 1.0. EVERYTHING ELSE uses f1 = 0.5. APG rhymes with 'apog' (lime/chalk) — imagine chalking 1.0 on the walls of an assembly hall and a parking garage. Regular office floors? Half chalk (0.5). The conservative default for board exams: use 1.0L unless told otherwise.

Why it works

The APG acronym collapses three exception cases into a memorable sound. The chalk image (apog) is a Filipino vernacular word that creates an unexpected, memorable connection.

Example usage

LRFD combo 4 for office building: use 0.5L (not 1.0L). LRFD combo 5 for concert hall (assembly): use 1.0L. When in doubt on the board exam, use 1.0L (conservative).

Recall trigger

'Apog on the assembly hall wall' → APG = 1.0, everything else = 0.5

Memory aid

Units rhyme: 'kPa is kN per square, multiply by meters there — one meter gives kN per m, two meters give kN flat, affirm!' Translation: kPa × m¹ = kN/m (line load), kPa × m² = kN (point load). This is the units chain for all tributary area problems. Never forget: kPa = kN/m² — so kN/m² × m = kN/m (beam), kN/m² × m² = kN (column).

Why it works

The rhyme makes the dimensional analysis stick phonetically. The explicit label (line load vs point load) at the end of each line reinforces the engineering meaning of the unit result.

Example usage

q = 5 kPa, s = 4 m → w = 5 × 4 = 20 kN/m ✓ (units: kPa × m = kN/m). q = 5 kPa, A = 16 m² → P = 5 × 16 = 80 kN ✓ (units: kPa × m² = kN).

Recall trigger

Rhyme about kPa × m → instantly check units in every tributary area problem

Memory aid

Chunk the uplift dead-load factors as a pair: LRFD → 0.9D (90% of dead load), ASD → 0.6D (60% of dead load). Why is LRFD larger? Because LRFD already uses factored nominal strength (φ×Rn) which has more built-in conservatism, so the load factor doesn't need to be as severe. Memory chunk: '9-6 → LRFD-ASD → Uplift pair.' Read it like a basketball score: LRFD 9, ASD 6 — LRFD wins by more (less severe reduction on D means larger net uplift checked).

Why it works

Pairing the two numbers as a 'score' (9-6) is a chunking technique that stores two separate values as a single memory unit. Filipino students who follow PBA or NBA basketball will recall scores easily.

Example usage

LRFD uplift check: U = 0.9D + 1.0W → remember LRFD gets the higher dead-load factor (0.9). ASD uplift: 0.6D + 0.6W → remember ASD uses 0.6D.

Recall trigger

'Basketball score 9-6' → LRFD uplift 0.9D, ASD uplift 0.6D

Memory aid

Story: Engr. Paz is reviewing designs at her firm in Makati. She knows that a structure must survive the WORST DAY of its life — not the average day. So she checks ALL applicable NSCP load combos and picks the one with the largest demand. She tells her junior engineer: 'Huwag maging optimista — design for the worst typhoon AND the worst crowd AND the worst earthquake, then pick whichever is biggest.' This is the essence of load combination design: find the governing (maximum) combination.

Why it works

Engr. Paz represents the professional mindset that students aspire to. The story embeds the design philosophy ('design for the worst day') in a mentorship narrative, which is emotionally resonant.

Example usage

After computing all 7 LRFD combos for a column, pick the one with the largest Pu. That is the governing factored load for design.

Recall trigger

Engr. Paz in Makati: 'Design for the worst day' → always find governing combination

Memory aid

Picture a Philippine building as a person: GRAVITY loads (D, L, Lr) push DOWN on their head (vertical forces — beams and slabs design). LATERAL loads (W, E) push from the SIDE trying to knock them over (lateral forces — columns, shear walls, frames). Combos 1–3 are pure gravity (head-pushers). Combos 4–5 mix gravity + lateral (head + side push). Combos 6–7 are uplift (trying to LIFT the person off the ground — minimum D). Draw this stick figure with arrows during review.

Why it works

Mapping load directions to body directions (down = gravity, sideways = lateral, up = uplift) creates a kinesthetic-spatial memory that is highly durable. The stick figure is a classic teaching aid that students can reproduce in exam margins.

Example usage

Exam: 'Which LRFD combo applies to a wind-dominated tall building column?' Think: sideways force + gravity → Combos 4 (1.2D+1.0W+1.0L+0.5Lr) or 6 (0.9D+1.0W for uplift side).

Recall trigger

Stick figure with arrows: down = combos 1-3, side = combos 4-5, up = combos 6-7

Answer

Dead Load (D)

Memory link

A10 — Tombstone visual: permanent, never moves, fixed weight

Answer

Combo 6: 0.9D + 1.0W (or Combo 7: 0.9D + 1.0E for earthquake)

Memory link

A4 — Mang Toni's roof in Pampanga typhoon story; A18 — Basketball score 9-6

Answer

w = q × s = 5 × 4 = 20 kN/m

Memory link

A8 — Banana harvest row analogy: strip of field width s

Answer

ASD Combo 6: D + 0.75L + 0.75(0.6W) + 0.75(Lr or R)

Memory link

A14 — Three-Quarter Club: D stays full, rest pays 75% discount

Answer

Earthquake Load (E)

Memory link

A12 — 1990 Luzon earthquake micro-story; E is the BOSS of lateral design

Answer

M_u = w_u × L² / 8 = 24 × 36 / 8 = 108 kN·m

Memory link

Formula mnemonic: 'w-L-squared over Eight: Weight times Length-squared, Eight is fate'

Answer

ASD — Allowable Stress Design. Sari-sari store method: plain prices, no multipliers.

Memory link

A13 — Jeepney analogy: ASD = pasahero system (pay per passenger, no boundary multipliers)

Answer

P_D = 4 × 30 = 120 kN; P_L = 3 × 30 = 90 kN; P_u = 1.2(120) + 1.6(90) = 144 + 144 = 288 kN

Memory link

A9 — Ate Sarah's food stall in Divisoria: P = q × A_t, then apply LRFD factors

Mnemonic

W = Queen × Spacing: 'The Queen (q, area load) rules her Strip (s, spacing) — and the result is the Weight per meter (w) she imposes on the beam.' q is royalty, s is her territory, w is what the beam feels.

When to use

Whenever a slab or distributed area load must be converted to a line load acting along the span of a beam. Used for all floor/roof beam design problems.

What each part means

w = line load on beam (kN/m); q = area load on slab (kPa = kN/m²); s = beam spacing or tributary width (m). Multiply kN/m² × m = kN/m.

Mnemonic

P = 'Pressure' times 'Area of Territory': The column's load is the full pressure (q) acting over its entire Tributary Area (A_t). Think: 'Pressure × Area = Force' — basic physics. P = q × A_t is just F = P × A rearranged from your fluid mechanics class.

When to use

To find the axial force in a column from floor/roof loads distributed over its tributary area. Multiply by number of floors for multi-storey columns.

What each part means

P = axial (vertical) load on column (kN); q = area load (kPa = kN/m²); A_t = tributary area supported by column (m²). Units: kN/m² × m² = kN.

Mnemonic

'One-point-Two Dead, One-point-Six Live' — the two magic numbers are 1.2 and 1.6. Remember: 1.2 < 1.6 because Dead is Dependable (lower factor) and Live is Loco (higher factor — more uncertain). Dead is dependable = 1.2. Live is loco = 1.6.

When to use

The first combo to check for pure gravity loading in LRFD design of beams, slabs, and columns. Almost always governs for typical floor systems without significant wind or seismic. Compare with 1.4D and other combos.

What each part means

U = factored design load (kN or kN/m); 1.2 = dead load factor (accounts for uncertainty in dead load); D = dead load; 1.6 = live load factor (higher because live load is more variable); L = live load.

Mnemonic

'w-L-squared over Eight: Weight times Length-squared, Eight is fate.' The '8' is fixed for simply supported UDL — no exceptions. Remember: the shape factor 8 comes from wL²/8 = (wL/2)(L/4)×2. If you forget the 8, recall that M_max for simply supported = wL²/8 always.

When to use

After computing w_u from LRFD load combination, use this formula to get the design moment for a simply supported beam. For other boundary conditions, use different moment formulas (e.g., wL²/12 at fixed end, wL²/24 at midspan for fixed-fixed).

What each part means

M_u = factored design moment (kN·m); w_u = factored UDL (kN/m) from LRFD combos; L = clear span (m); 8 = constant for simply supported beam under UDL.

Mnemonic

'Wind enters at 1.2-1.0-1.0-half': Dead still gets 1.2, Wind and Live both get 1.0 (equal billing when wind leads), roof gets half. Think: 'When Wind comes in full (1.0W), Dead and Live share 1.2 and 1.0 billing, roof gets half-off.'

When to use

When wind load is significant alongside gravity. Typical for tall buildings, open structures, or roofs subject to wind pressure. Compare with Combo 6 (0.9D + 1.0W) for the uplift side of wind action.

What each part means

1.2D = factored dead; 1.0W = full factored wind (wind is leading variable load); 1.0L = companion live (or 0.5L for most occupancies per f1 factor); 0.5(Lr or R) = half the roof load (companion action).

Mnemonic

'Earthquake enters: 1.2-1.0-1.0, no roof companion.' Seismic combo drops the roof live load term (Lr/R = 0 in seismic — if it's shaking, the roof is already risky enough). Remember: Combo 5 = no roof term. Combo 4 = has roof term (0.5Lr). That's the only difference between the wind and earthquake gravity-lateral combos.

When to use

When seismic load controls lateral design. Critical for Philippine buildings in Seismic Zone 4 (most of Luzon, Visayas, Mindanao). Must be combined with appropriate seismic redundancy and detailing requirements per NSCP.

What each part means

1.2D = factored dead; 1.0E = full seismic load (already includes overstrength effects per NSCP seismic provisions); 1.0L = companion live (note: no Lr/R term in earthquake combo).

Recall test

Without looking, write all 7 LRFD combos in 2 minutes. Check each factor: D-factor, L-factor, Lr/R-factor, W-factor, E-factor. Did you get the 0.9D uplift combos?

Memory chain

Story chain: (1) A DEAD WORKER gets 40% overtime (1.4D). (2) GRAVITY PARTY: Dead+Live+half-roof — the biggest gravity bash (1.2D+1.6L+0.5Lr). (3) ROOF IS KING: roof load gets the big factor when it's the lead (1.2D+1.6Lr). (4) WIND JOINS: full wind arrives with dead and live (1.2D+1.0W+1.0L). (5) EARTHQUAKE: seismic takes over, no roof this time (1.2D+1.0E+1.0L). (6) WIND BLOWS ROOF OFF: only 90% dead can resist (0.9D+1.0W). (7) EARTHQUAKE TIPS BUILDING: only 90% dead resists (0.9D+1.0E). Chain key words: Dead-Gravity-Roof-Wind-Quake-BlowOff-Tip.

Items to remember

• 1. 1.4D
• 2. 1.2D + 1.6L + 0.5(Lr or R)
• 3. 1.2D + 1.6(Lr or R) + (1.0L or 0.5W)
• 4. 1.2D + 1.0W + 1.0L + 0.5(Lr or R)
• 5. 1.2D + 1.0E + 1.0L
• 6. 0.9D + 1.0W
• 7. 0.9D + 1.0E

Recall test

Name all 6 NSCP load types from memory. For each, state whether it is permanent (D), variable (L, Lr, W, E, R), or environmental (W, E, R).

Memory chain

Use the sentence: 'Dalawang Llamas Laging Walang Emosyon, Relax.' (Two Llamas Always Without Emotion, Relax.) First letters: D-L-L-W-E-R → Dead, Live, Lr, Wind, Earthquake, Rain. The absurd image of two unemotional llamas relaxing in a rainstorm is highly memorable.

Items to remember

• D = Dead load (permanent)
• L = Live load (occupancy)
• Lr = Roof live load (maintenance)
• W = Wind load
• E = Earthquake load
• R = Rain load

Recall test

Write all 7 ASD combos from memory. Pay special attention to the 0.75 factors in combos 4 and 6, and the 0.6D in combo 7. Compare to LRFD: which is 0.6D (ASD) vs 0.9D (LRFD) for uplift?

Memory chain

ASD story: (1) Just Dead, nothing else (D). (2) Dead friends join Live (D+L). (3) Dead goes to the Roof (D+Lr). (4) Three-quarter party: dead plus 75% of everything else (D+0.75L+0.75Lr). (5) Wind appears at 60% strength (D+0.6W). (6) The mega-party: dead+75% live+75%×60%wind+75%roof — the most complex combo. (7) Uplift combo: only 60% dead resists 60% wind or 70% quake. Chain: Dead-DeadLive-DeadRoof-ThreeQuarter-Wind-MegaParty-Uplift.

Items to remember

• 1. D
• 2. D + L
• 3. D + (Lr or R)
• 4. D + 0.75L + 0.75(Lr or R)
• 5. D + 0.6W (or D + 0.7E)
• 6. D + 0.75L + 0.75(0.6W) + 0.75(Lr or R) — and seismic companion
• 7. 0.6D + 0.6W (or 0.6D + 0.7E)

Recall test

A floor has q_D = 3 kPa, q_L = 2 kPa, beam spacing = 4 m (interior), span = 8 m. Without notes, find: (a) beam line loads, (b) LRFD factored UDL, (c) design moment M_u.

Memory chain

ITWCPA: 'I Took Water Carrying Pails Again.' Identify → Tributary → Width → Column-area → P=qAt → Apply-combos. Each word maps to a step. Say it 3 times and you'll remember the 6-step process.

Items to remember

• Step 1: Identify member type (beam or column)
• Step 2: Determine tributary width (beam: s for interior, s/2 for edge)
• Step 3: For beam — multiply area load by tributary width: w = q × s
• Step 4: For column — identify tributary area A_t = Lx × Ly
• Step 5: For column — compute P = q × A_t
• Step 6: Apply load combination factors to get design load

Recall test

Without looking: what factor applies to (a) Dead load in gravity combo? (b) Live load in gravity combo? (c) Wind in lateral combo? (d) Dead load in uplift combo? (e) Roof companion in combo 2?

Memory chain

Remember the LRFD factor set as a phone number-like sequence: '1.4 | 1.2-1.6 | 1.0-1.0 | 0.9-0.5'. Read it as: 'fourteen, twelve-sixteen, ten-ten, nine-five.' Like a mobile number: 1.4-1.2-1.6-1.0-1.0-0.9-0.5. Drill it 5 times daily during your review week.

Items to remember

• Dead load factor in main gravity combo: 1.2
• Live load factor in governing gravity combo: 1.6
• Dead load-only combo factor: 1.4
• Wind/Earthquake factor in lateral combo: 1.0
• Uplift dead load factor (LRFD): 0.9
• Roof/Rain companion factor: 0.5