BRIDGE 1

Cant and banking

What are other terms commonly used for superelevation?

e + f = V²/127R

What formula is used in the presentation to calculate superelevation?

0.07

What is the maximum allowable superelevation (eₘₐₓ) stated in the presentation?

0.15

What is the maximum allowable lateral friction factor (fₘₐₓ)?

To support the roadway, pedestrian traffic, or other loads

What is the purpose of a bridge floor or bridge deck system?

Gravel foundation surface

Which of the following is NOT listed as a bridge floor surface?

Concrete

Which is classified as a conventional rigid surface?

Asphalt wearing course

Which is classified as a conventional flexible wearing layer?

Service systems attached to, carried within, or passing beneath a bridge

What are bridge utilities?

Road pavement

Which of the following is NOT listed as a bridge utility in the presentation?

To remove water from the road surface and protect the pavement

What is the main purpose of roadway drainage?

DPWH(Department of Public Works and Highways)

Which Philippine government agency is mainly in charge of road drainage design standards?

Flooding occurs and can damage the pavement

What happens when aroad's drainage system cannot handle heavy rainfall?

To pumpoutfloodwater that cannot drain by gravity alone

What is a "pumping station" used for in low-lying areas like Metro Manila?

Curb and gutter

Which of the following is a common component of a roadway drainage system?

Carries water underneath the road to a waterway

What does a "box culvert" do in a drainage system?

A structure that separates a road and a railway at different levels

What is a "grade separation" in railroad engineering?

Grade separation

What is another common name for a railroad overpass?

PNR (Philippine National Railways) Metro Commuter Line

Which Philippine railway line used to cross Metro Manila roads at ground level (at-grade)?

It removes the risk of a vehicle-train collision at that crossing

What is the main benefit of building a railroad overpass at a busy crossing?

To provide basic rules for safe and proper bridge design

What is the main purpose of general provisions in bridge engineering?

The bridge is strong, stable, and safe

What does structural integrity mean?

To provide alternative load paths if a member is damaged

3. What is the purpose of redundancy in a bridge?

Applied demand with structural capacity

What does DCR (Demand-to-Capacity Ratio) compare?

Demand exceeds the available capacity

What does a DCR greater than 1.0 generally indicate?

Water flow, erosion, scour, and maintenance

What is an important consideration when selecting a bridge location over a river or stream?

To allow possible future transportation improvements

Why should bridge locations consider future road widening?

Structural behavior as gravity loads are gradually increased

What is push-down analysis used to evaluate?

B. Cebu–Cordova Link Expressway (CCLEX)

Which bridge is approximately 8.9 km long and connects Cebu City and Cordova?

San Juanico Bridge

Cebu–Cordova Link Expressway (CCLEX)

North Luzon Expressway (NLEX) (Candaba Viaduct)

What are the top three longest bridges in the Philippines mentioned in the first report?

The calculated clear opening beneath a bridge designed to accommodate natural river or stream flows

What do waterways refer to in a bridge structure?

A specific design flood

Bridge waterways are sized to pass what?

The maximum allowable backup water that will not risk flooding adjacent properties

What is upstream ponding?

To prevent floating debris from trapping against the girders

Why is sufficient freeboard needed above the design flood level?

. Washing away of soil around bridge piers and abutments

What is foundation scour?

When crossing smaller streams or managing localized cross-roadway drainage

When are culverts commonly used instead of bridges?

AASHTO Guide on the Hydraulic Design of Culverts

What guide must be followed for the selection of culvert location, length, and waterway openings?

Aligned with the natural stream channel

How should a culvert be positioned wherever possible?

The roadway geometry

What determines the length of a culvert?

Process peak runoff discharges without creating excessive headwater

What must the interior cross-sectional area of a culvert opening be large enough to do?

To provide safe and continuous passage over an obstacle

What is the primary purpose of a bridge?

DPWHDesign Guidelines, Criteria and Standards (DGCS) 2015

Which DPWH documentis a major reference for bridge design in the Philippines?

4.88 m

What is the minimum vertical clearance above national highways specified by DPWH?

0.15 m

What additional allowance should be considered for future road surfacing according to the cited DPWH clearance requirement?

5.18 m

What is the resulting clearance requirement cited for pedestrian footbridges over roadways?

Scour and hydraulic conditions

Which of the following is a major concern when designing a bridge across a river?

To provide vertical space between the design water level and the bridge structure

What is the main purpose of providing freeboard in a bridge crossing?

105.03 m

A roadway has an elevation of 100.00 m. If the required clearance is 4.88 m and the future surfacing allowance is 0.15 m, what is the minimum approximate elevation of the underside of the bridge?

AASHTO LRFDBridge Design Specifications

Which design specification is commonly used together with DPWH bridge design requirements for the structural design of bridges in the Philippines?

Article 3.6.1.1

According to AASHTO LRFD, which article covers vehicular live load?

The weight and arrangement of vehicles on the bridge

What does vehicular live load represent?

The additional effect caused by moving vehicles

What is impact load?

Because vehicles can produce vibration and additional forces while moving

Why is impact considered in bridge design?

Horizontal braking force

What force is produced when a vehicle suddenly breaks on a bridge?

When avehicle travels along a curved roadway

When does centrifugal force occur?

It generally increases

What happens to centrifugal force when a vehicle travels faster around a curve?

They help determine whether the bridge can safely carry traffic

Why are highway loads important in bridge design?

4.88 m

What is the minimum vertical clearance between curbs for a highway tunnel?

9.00 m

For a two-lane tunnel, what is the minimum wall-to wall clearance specified in the text?

At least 7.32 m and at least 0.61 m wider than the approach traveled way

The minimum roadway width inside a tunnel must be:

450 mm

What is the minimum curb or sidewalk width on each side of a tunnel?

Constructed below surrounding ground level and generally open to the sky

A depressed roadway is best described as a highway that is:

9.14 m (30 ft)

The minimum wall-to-wall clearance for a two-lane depressed roadway is approximately:

Drainage and pumping systems

Which design consideration is especially important for depressed roadways because they are below ground level?

Contain and redirect errant vehicles

What is the primary function of a traffic railing?

Smooth and continuous with posts set back

According to the standard, the traffic-facing side of a railing should be:

Provide a smooth transition with proper anchorage

At bridge ends, traffic railings should:

Superstructure

Which part of a bridge is primarily responsible for carrying traffic loads?

Toproducecritical structural stresses

Whatis the main purpose of standard truck loadings in bridge design?

Atractor truck with a semi-trailer

Which statement correctly describes MS (HS) loading?

. 80%

. For a standard M(H) truck, what percentage of the total weight is carried by the rear axle?

144kN

Astandard M18(H-20-44)truck has afront axle load of 36 kN. What is its rear axle load?

Traffic lane represents actual vehicle routing, while design lane is used for structural load placement.

Whatis the main difference between traffic lane and design lane?

3.6 m

According to the AASHTO, what is the standard width of a traffic lane?

Theloadis increased by 100%

Under the overload provisions, how is heavy loading applied to a single lane?

150%

Whatis the maximumallowable percentage of the basic allowable stresses when considering combined dead, live, and impact stresses from overload?

Torepresent different parameters using letters or symbols

What is the main purpose of notations in bridge design?

DeadLoad

what doesthe notation “D” generally represent in bridge loading?

DeadLoad

Which load represents the permanent weight of the bridge itself?

Toensurethebridgecansafely resist the expected conditions

Whydoengineers need to consider different loads and forces acting on a bridge?

To determine the maximum safe stress a structural member can experience

What is the purpose of allowable stress?

Theassumedloads

What should be clearly shown when stress sheets are required?

. Theassumedloads

What should be clearly shown when stress sheets are required?

Toidentify the contribution of each load

Whyshouldstresses caused by different loads be identified separately?

Because different applicable loads can act simultaneously

. Whyareloadcombinations necessary?

Centrifugal force

Which force is particularly important when vehicles travel along a curved bridge?

Vertical, lateral, and longitudinal

For a skewedbridge, which three directions of force need to be considered?

Fixed, stationary weight of the bridge structure and permanent attachments

. Which of the following best describes dead loads in bridge engineering?

The weight of fundamental structural components and nonstructural permanent attachments

Under LRFD specifications, what does component load (DC) refer to?

DW

What code designator is used for future wearing surfaces and utilities under LRFD dead load categories?

72 kips (320 kN)

What is the total weight of the standard AASHTO HL-93 design truck?

14 feet to 30 feet

What is the variable spacing range between the rear two axles of the HL-93 design truck?

25,000 lb axles spaced 4 feet apart

The AASHTO design tandem consists of a pair of axles weighing how much each, and spaced how far apart?

0.64 kips per linear foot

What is the magnitude of the uniform Design Lane Load specified in HL-93?

. 10 feet

Across what transverse width is the Design Lane Load applied in the design lane?

NSCP Volume II

Which code explicitly adopts AASHTO Standard Specifications for Highway Bridges in the Philippines?

Which Philippine government agency fully adopts AASHTO standards for bridge design dead and live loads?

DPWH