Structural Engineering Exam (SE) Vertical Forces (Gravity/Other) and Incidental Lateral — Breadth Syllabus

Vertical Forces (Gravity/Other) and Incidental Lateral — Breadth syllabus — full chapter and topic list

Expand any chapter to see its topics and sub-topics. This is the whole examinable outline for Vertical Forces (Gravity/Other) and Incidental Lateral — Breadth in Structural Engineering Exam (SE), not a summary of it.

1. 1

   Loads and Load Combinations (Gravity)

   5 topics

   • Dead, Live, and Roof Live Loads per ASCE 7
     • Dead load determination and self-weight estimation
     • Live load magnitudes by occupancy and live load reduction
     • Roof live loads and minimum uniformly distributed loads
   • Snow, Rain, and Ice Loads
     • Flat and sloped roof snow loads, exposure and thermal factors
     • Drift, sliding snow, and unbalanced snow on gable/curved roofs
     • Rain loads and ponding instability checks
   • Soil Lateral Pressures and Fluid Loads
     • At-rest, active, and passive earth pressures
     • Hydrostatic and groundwater surcharge effects
   • Load Combinations for Strength and Service
     • LRFD and ASD combinations per ASCE 7 Chapter 2
     • Pattern loading and most-unfavorable arrangements
   • Self-Straining, Thermal, and Construction Loads
2. 2

   Analysis of Statically Determinate and Indeterminate Structures

   5 topics

   • Equilibrium, Reactions, and Internal Forces
     • Shear and moment diagrams for beams and frames
     • Axial-force diagrams and truss member forces
   • Deflections and Compatibility
     • Virtual work and moment-area methods
     • Deflection limits and serviceability criteria
   • Indeterminate Analysis Methods
     • Moment distribution and slope-deflection
     • Approximate methods (portal and cantilever for gravity)
   • Influence Lines and Moving Loads
   • Idealization, Modeling, and Boundary Conditions
3. 3

   Foundations and Retaining Structures

   4 topics

   • Shallow Foundation Design
     • Bearing capacity and allowable bearing pressure
     • Spread footing sizing, settlement, and eccentric loading
     • Combined and mat foundation behavior
   • Deep Foundations
     • Pile and drilled shaft axial capacity
     • Pile group action and lateral resistance
   • Retaining Walls
     • Stability against sliding, overturning, and bearing
     • Cantilever and gravity wall design
   • Geotechnical Parameters and Soil-Structure Interaction
4. 4

   Structural Systems Integration and Material Behavior

   4 topics

   • Load Path and System Behavior
     • Gravity load path from roof to foundation
     • Tributary area and load distribution
   • Material Properties Across Steel, Concrete, Wood, Masonry
   • Connection Concepts and Force Transfer
   • Constructability and Detailing for Gravity Systems

Vertical Forces (Gravity/Other) and Incidental Lateral — Breadth flashcards for Structural Engineering Exam (SE)

23 of 59 cards from the Vertical Forces (Gravity/Other) and Incidental Lateral — Breadth deck — real questions with worked answers.

1. Per ASCE 7, what is the minimum uniformly distributed roof live load $L_r$ for an ordinary flat roof, and how is it reduced?

   The base roof live load is $L_r = 20\ \text{psf}$. It is reduced as $L_r = 20 R_1 R_2$, where $0.6 \leq R_1 R_2 \leq 1.0$. $R_1$ depends on tributary area $A_t$ and $R_2$ on roof slope, so $L_r$ may be reduced to a minimum of $12\ \text{psf}$.

2. State the ASCE 7 live load reduction formula for members supporting large tributary areas.

   $$L = L_0\left(0.25 + \frac{15}{\sqrt{K_{LL} A_T}}\right)$$ where $L_0$ is the unreduced live load, $K_{LL}$ is the live load element factor, and $A_T$ is the tributary area in $\text{ft}^2$. $L \geq 0.50 L_0$ for members supporting one floor and $L \geq 0.40 L_0$ for members supporting two or more floors.

3. What value of $K_{LL}$ does ASCE 7 assign to interior columns and to interior beams for live load reduction?

   Interior columns (and exterior columns without cantilever slabs): $K_{LL} = 4$. Interior beams (and edge beams without cantilever slabs): $K_{LL} = 2$. The factor converts tributary area to an effective influence area.

4. What is dead load, and what are typical unit weights of normal-weight concrete and structural steel used in dead load calculations?

   Dead load is the weight of all permanent construction including the structure, finishes, fixed equipment, and cladding. Normal-weight reinforced concrete is about $150\ \text{pcf}$ ($\approx 23.6\ \text{kN/m}^3$) and structural steel is about $490\ \text{pcf}$ ($\approx 77\ \text{kN/m}^3$).

5. Write the ASCE 7 flat roof snow load equation and define each term.

   $$p_f = 0.7 C_e C_t I_s p_g$$ where $p_f$ is flat roof snow load, $C_e$ is the exposure factor, $C_t$ is the thermal factor, $I_s$ is the snow importance factor, and $p_g$ is the ground snow load. The $0.7$ is the basic exposure (ground-to-roof) conversion.

6. How is the sloped roof snow load $p_s$ obtained from the flat roof snow load in ASCE 7?

   $$p_s = C_s p_f$$ where $C_s$ is the roof slope factor (a function of roof slope, thermal factor $C_t$, and roof surface slipperiness). Warm, slippery roofs shed snow, giving smaller $C_s$ at lower slopes.

7. What controls the design of a roof for rain load, and what failure mode does ASCE 7 guard against with rain provisions?

   Rain load $R = 5.2(d_s + d_h)$ (psf), where $d_s$ is the static head (depth at the secondary drain inlet) and $d_h$ is the hydraulic head above it. The provisions guard against ponding instability, where roof deflection allows water to accumulate, increasing load and deflection progressively.

8. Give the ASCE 7 atmospheric ice load thickness relation and note what governs ice loads.

   The design ice thickness is $t_d = t I_i f_z$, where $t$ is the nominal radial glaze ice thickness from maps, $I_i$ is the ice importance factor, and $f_z$ is a height factor $f_z = (z/33)^{0.10}$. Ice loads add weight and increase the projected wind area of members and cables.

9. How are lateral soil pressures on basement and retaining walls classified, and which coefficients correspond to each?

   At-rest pressure ($K_0$) applies to restrained, non-yielding walls (e.g., braced basement walls). Active pressure ($K_a$) develops when a wall yields away from the soil. Passive pressure ($K_p$) develops when a wall is pushed into the soil. Generally $K_a < K_0 < K_p$.

10. Write Rankine's active and passive earth pressure coefficients for a level cohesionless backfill.

    $$K_a = \tan^2\!\left(45^\circ - \frac{\phi}{2}\right), \qquad K_p = \tan^2\!\left(45^\circ + \frac{\phi}{2}\right)$$ where $\phi$ is the soil's effective friction angle. Note $K_p = 1/K_a$.

11. What is the at-rest earth pressure coefficient for normally consolidated soil (Jaky's equation)?

    $$K_0 = 1 - \sin\phi$$ for normally consolidated soil. For overconsolidated soil, $K_0 = (1-\sin\phi)\,\mathrm{OCR}^{\sin\phi}$, where OCR is the overconsolidation ratio.

12. How does ASCE 7 define the fluid load $F$, and how does hydrostatic pressure vary with depth?

    $F$ is the load due to fluids with well-defined pressures and maximum heights. Hydrostatic pressure varies linearly with depth: $p = \gamma_f h$, where $\gamma_f$ is fluid unit weight (water $\approx 62.4\ \text{pcf}$) and $h$ is depth below the free surface. The resultant acts at $h/3$ above the base of a triangular distribution.

13. List the ASCE 7 LRFD (strength) basic load combinations including dead, live, roof live, snow, rain, and wind.

    1) $1.4D$; 2) $1.2D + 1.6L + 0.5(L_r\ \text{or}\ S\ \text{or}\ R)$; 3) $1.2D + 1.6(L_r\ \text{or}\ S\ \text{or}\ R) + (L\ \text{or}\ 0.5W)$; 4) $1.2D + 1.0W + L + 0.5(L_r\ \text{or}\ S\ \text{or}\ R)$; 5) $0.9D + 1.0W$. (Earthquake combinations replace $W$ with $E$ using $1.2D+E+L$ type forms.)

14. State the ASCE 7 ASD (service/allowable stress) basic load combinations for $D$, $L$, $L_r$, $S$, $R$.

    1) $D$; 2) $D + L$; 3) $D + (L_r\ \text{or}\ S\ \text{or}\ R)$; 4) $D + 0.75L + 0.75(L_r\ \text{or}\ S\ \text{or}\ R)$; 5) $D + (0.6W\ \text{or}\ 0.7E)$. Loads combine at full nominal value (no overload factors) for ASD.

15. What is a self-straining load $T$, and give two structural examples.

    A self-straining (restraint) load $T$ is a force induced by restrained dimensional change rather than external load. Examples: thermal expansion/contraction restrained by supports, differential foundation settlement, shrinkage of concrete, prestressing, or moisture/creep movements. Magnitude depends on member stiffness and degree of restraint.

16. How is the axial force from fully restrained uniform thermal expansion calculated?

    For a member fully restrained against a uniform temperature change $\Delta T$, the induced stress is $\sigma = E \alpha \Delta T$ and the force is $$P = E A \alpha \Delta T$$ where $E$ is modulus of elasticity, $A$ is area, and $\alpha$ is the coefficient of thermal expansion. Free expansion produces no stress.

17. What are construction loads, and how do ASCE 7 / SEI 37 treat them?

    Construction loads are temporary loads during erection: material storage, equipment, formwork, shoring, and personnel. They are evaluated with construction-specific load combinations (SEI 37-14), often using reduced load factors but accounting for conditions (partial bracing, fresh concrete) not present in the completed structure.

18. State the three equations of static equilibrium for a planar (2D) rigid body.

    $$\sum F_x = 0, \qquad \sum F_y = 0, \qquad \sum M_z = 0$$ The sum of horizontal forces, vertical forces, and moments about any point must each equal zero. A 3D body has six equations (three force, three moment).

19. How do you determine static determinacy of a planar truss with $m$ members, $r$ reactions, and $j$ joints?

    Compare $m + r$ to $2j$. If $m + r = 2j$ the truss is statically determinate; if $m + r > 2j$ it is indeterminate (degree $= m+r-2j$); if $m + r < 2j$ it is unstable (a mechanism). The criterion presumes a proper, non-critical geometry.

20. Give the static determinacy classification formula for a planar frame.

    With $m$ members, $r$ reactions, $j$ joints, and $c$ condition (internal release) equations: degree of indeterminacy $= (3m + r) - (3j + c)$. Equal to zero means determinate; greater than zero means indeterminate; less than zero means unstable.

21. What is the relationship among load $w$, shear $V$, and moment $M$ along a beam?

    $$\frac{dV}{dx} = -w(x), \qquad \frac{dM}{dx} = V(x)$$ Thus the slope of the shear diagram equals the negative distributed load, and the slope of the moment diagram equals the shear. The change in shear equals the area under the load diagram; the change in moment equals the area under the shear diagram. Maximum moment occurs where $V = 0$.

22. For a simply supported beam of span $L$ under uniform load $w$, give the maximum shear, maximum moment, and maximum deflection.

    $$V_{max} = \frac{wL}{2}, \qquad M_{max} = \frac{wL^2}{8}, \qquad \delta_{max} = \frac{5wL^4}{384EI}$$ Maximum moment is at midspan; maximum shear is at the supports.

23. For a cantilever beam of length $L$ with a point load $P$ at the free end, give the maximum moment and tip deflection.

    $$M_{max} = PL\ \text{(at the fixed support)}, \qquad \delta_{tip} = \frac{PL^3}{3EI}$$ The moment is maximum at the fixed end and zero at the free end.

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