STRUCTURE SECTION COMMENTS
Valley Boulevard Overcrossing
OK. Verify shear capacity calculation.
OK. For Item 2, remove “Sta.” from BB on Drawing S
On Drawing S
203, remove “Sta.” from the leader at the east
to make it consistent with the west abutment.
On Drawing S
205, correct the spelling for “Elastomeric”.
Also, in the “Abutment 1 Elevation” view, hatch the areas with
expanded polystyrene in accordance with the legend.
OK. See to our
response to Item 422.
On Sheet 4
2 of the calculations, in the shear friction design of the
backwall reinforcement, the µ factor used is 1.4, which corresponds to
normal weight concrete placed monolithically, per AASHTO 22.214.171.124.
The roughened constr
uction joint should be removed. Otherwise, the µ
factor to be used on Sheet 4
2 should be 1.0.
The ½” elastomeric bearing pad is being used to facilitate the backwall
breaking off under seismic load. Since the backwall is designed to
remain elastic under
all conditions, the elastomeric bearing pad should
Expansion joint filler does not allow rotation of the structure approach
slab as intended. Use expanded polystyrene instead.
In Detail A, “Shear Key Detail At
North End,” the rebar designation
should be corrected.
OK. Regarding Item 6, Regarding Item 7, the CIP concrete facing wall
may not be thick enough to accommodate the minimum bending radius of
the #5 dowels and minimum clearance.
OK. On Drawing S
Expanded polystyrene facilitates the pinned connection at the top of
the bent column. Joint filler does not.
Indicate centerline of column.
OK. On Drawing S
The Typical Section should show the median and the width of traveled
way, in accordance
with Bridge Design Details 3
Show chain link railing in “Partial Typical Section”, or add note
indicating the chain link railing is not shown for clarity.
OK. Items 2 and 3 were not addressed. Drawing S
217 is missing from
the 100% Submittal.
OK. For Item 3, check if Highways Section or Traffic and Lighting Division
had any comments.
On Sheet 3
33, the calculations show #5 stirrups at 12 inch spacing at
the overhang and mid
span of the bent cap and #5 stirrups at 6 in
spacing near the columns. On Drawing S
210, however, the #5
stirrups are shown at 24 inches at the overhang and mid
span of the
bent cap and at 12 inches near the columns.
OK. It is not clear from which SAP model and from which node the
axial force P
For Item 6, if the backwall is designed not to fail, it is not recommended
for a construction joint to be intentionally placed at the
backwall/abutment seat interface. If one is placed, monolithic
construction cannot be assume
d (µ≤1.0). Ensure that adequate
reinforcement has been provided to facilitate shear transfer between
the backwall and the abutment seat.
The surcharge pressure of 2 feet used in the design of forces on the
abutment is not correct. Surcharge loa
ds on abutments should
conform to AASHTO Table 126.96.36.199
1, as was done on page 3
the calculations for the Avocado Channel Cover.
The Extreme IB uses a load factor of 0.5 for the active soil pressure.
This is incorrect. Per Table 3.4.1
1 of the Cali
fornia Amendments to
the AASHTO LRFD Bridge Design Specifications
Fourth Edition, in
the Extreme Event I case, the load factor for the active soil pressure
(EH) is 1.0, as is the load factor for water pressure (WA).
OK. For Item 3, refer to respo
nse to Item 440.
As mentioned elsewhere, the column effective moment of inertia
should be calculated from the moment curvature analysis, to account
for the effects of moment on the column.
Puente Avenue Undercrossing
Indicate the pile tip elevations and required strengths in tension and
compression for the CIDH piles on Drawing S
OK. See comment for Item 455.
OK. Response indicates that walls are checked for hydrostatic and soil
pressure. See comment on Item 47
The note added does not mention contact plates.
OK except for the following items:
2. Remove extraneous lines from the bent cap ties.
OK except for the following items:
5. Show locations of no splice zones. Construction stage 2 has cap
section longer than 60 feet.
6. Add ties around the cap beam side face reinforcement to improve
OK, provided that AREMA requirements surpass Caltrans seismic design
Per Caltrans Memo to Designer 7
1, page 6, shortening of 0.01’ per 100
feet is expected for pre
tensioned concrete structures, which covers
precast girders. Where in Caltrans Memo to Designers does it say that
prestress and shrinkage do not apply to preca
31 of the calculations still uses a cap width of 7 feet. Per Sheet 3
19 and Drawing S
108, the cap width is 6 feet.
OK. In the response, it is indicated that 5,440 in
is the correct value. The
current value on Sheet 3
37 is 4,62
value of 5,440 in
on Sheet 3
39 does not match that shown on
OK. Ensure that the section meets AREMA minimum reinforcement
OK. On Sheet 3
127, it appears that a 0.5 factor was used for the soil.
Based on the loa
d combinations shown on Sheet 3
142, the soil and water
both have a load factor of 1.0. Ensure that the proper load factors are
OK. Confirming response.
Disagree. XTract runs are needed to provide yield and curvature data for
splacement capacity. Per AREMA Section 1.4, a bridge’s ability
to withstand large relative displacements factors into the assessment of its
vulnerability to seismic effects.
OK. 1. Was negative moment demand in the bent cap checked?
2 and 3. It
is indicated on Sheet 3
368 that the bridge’s longitudinal
deflection will be limited by the gap. While the backwall is designed to
remain elastic under a level 3 seismic event, the soil behind the
backwall will exhibit deformation and add to the deflecti
deflection of the bridge may be greater than the gap. The
displacement capacity of the bridge substructure should be larger
than the expected demand deflection.
Show through calculations that the embedment length and edge
distance of the anchor bolts are sufficient to develop the anchor bolt
strength and resist the girder shear demands shown on Sheet 3
Also, the statement on Sheet 3
364 about “…deduct facto
Caltrans SDC µ
= 5 for multi
column, which doesn’t control
design…” is not clear.
Per Caltrans SDC 2.2.3, the displacement ductility demand
is defined as the global frame displacement demand
divided by the displacement at which a particular sub
yields. In other words, for a multi
column bent, the final
should not be greater than 5 times the
displacement at which yielding begins. Since the demand
displacement on a structure does not change, the member
must be designed
so that its yield displacement is within 5
times that of the demand displacement. Displacement
ductility demand is a measure of the imposed post
deformation on a member. No license is given here to