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Caltrans Standard Specifications 2015

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Author(s): Caltrans
Publisher: Caltrans
Year: 2015
Link: PDF 
Subject: Construction, specifications
Size: 1155 pages, 14 MB
Caltrans Standard Specifications 2015

These standard specifications are published by the State of California Department of Transportation (Caltrans), for use on Caltrans projects. They ae also widely used or referred to by other agencies in California and elsewhere.

The specifications are divided into 12 divisions.

Division I includes general specifications applicable to every contract unless specified as applicable only under certain conditions.

Division II includes specifications for general construction applicable to every contract unless specified as applicable only under certain conditions.

Divisions III through X include construction specifications for specific bid items.

Division XI includes specifications for common materials. For a material specified in this division, that material specified in any section must comply with the specifications in division XI.

Division XII includes construction specifications for buildings. 



Caltrans Riprap Sizes

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This has been superseded by Caltrans New Riprap Classes.

D50 Equivalent Spherical Diameter
RSP Class D50Size1 D50Weight
  inches pounds
8 Ton 71 17600
4 Ton 56 8800
2 Ton 45 4400
1 Ton 36 2200
1/2 Ton 28 1100
1/4 Ton 23 550
Light 16 200
Facing 12 75
Backing No 1 12 75
Backing No 2 8 25
Backing No 3 4 2/3 5
Small RSP (7-inch) 3 1 1/3
Small RSP (5-inch) 2 2/5
Small RSP (4-inch) 1 1/20
1Assumes rock density = 165 lb/ft3

Caltrans Standard Specifications

72-2 ROCK SLOPE PROTECTION

72-2.02A Rock

For method A placement and the class of RSP described, comply with the rock grading shown in the following table:

Rock Grading for Method A Placement
Rock size Percentage larger thana
Class
8T 4T 2T 1T 1/2 T
16 Ton 0–5 — — — —
8 Ton 50–100 0–5 — — —
4 Ton 95–100 50–100 0–5 — —
2 Ton — 95–100 50–100 0–5 —
1 Ton — — 95–100 50–100 0–5
1/2 Ton — — — 95–100 50–100
1/4 Ton — — — — 95–100
aFor any class, the percentage of rock smaller than the smallest rock size must be determined on the basis of weight. For all other rock sizes within a class, the percentage must be determined on the basis of the ratio of the number of individual rocks larger than the smallest size shown for that class compared to the total number of rocks.

For method B placement and the class of RSP described, comply with the rock grading shown in the following table:

Rock Grading for Method B Placement
Rock size Percentage larger thana
Class
1 T 1/2 T 1/4 T Light Facing No. 1 No. 2 No. 3
2 Ton 0–5 — — — — — — —
1 Ton 50–100 0–5 — — — — — —
1/2 Ton — 50–100 0–5 — — — — —
1/4 Ton 95–100 — 50–100 0–5 — — — —
200 lb — 95–100 — 50–100 0–5 0–5 — —
75 lb — — 95–100 — 50–100 50–100 0–5 —
25 lb — — — 95–100 90–100 90–100 25–75 0–5
5 lb — — — — — — 90–100 25–75
1 lb — — — — — — — 90–100
aFor any class, the percentage of rock smaller than the smallest rock size must be determined on the basis of weight. For all other rock sizes within a class, the percentage must be determined on the basis of the ratio of the number of individual rocks larger than the smallest size shown for that class compared to the total number of rocks.

Rock must have the values for the material properties shown in the following table:

Rock Material Properties
Property California Test Value
Apparent specific gravity 206 2.5 minimum
Absorption 206 4.2% maximum
Durability index 229 52 minimum

Select rock so that shapes provide a stable structure for the required section. If the slope is steeper than 2:1, do not use rounded boulders and cobbles. Angular shaped rock may be used on any planned slope. Flat or needle shaped rock must not be used unless the individual rock thickness is greater than 0.33 times the length.

72-2.02B Fabric

Fabric must be RSP fabric that complies with the class shown in the following table:

Fabric Class
Class Largest rock grading class used in slope protection
8 1 ton or smaller
10 Larger than 1 ton

72-4 SMALL-ROCK SLOPE PROTECTION

72-4.02 MATERIALS

Rock must be cobble, gravel, crushed gravel, crushed rock, or any combination of these.

If the rock layer is shown as 7 inches thick, comply with grading shown in the following table:

Rock Grading for 7-inch-Thick Layer
Sieve sizes Percentage passing
5 inch 100
4 inch 90–100
3 inch 25–40
2 inch 0–10

If the rock layer is shown as 5 inches thick, comply with the grading shown in the following table:

Rock Grading for 5-inch-Thick Layer
Sieve sizes Percentage passing
4 inch 100
3 inch 90–100
2 inch 25–40
1 inch 0–10

If the rock layer is shown as 4-inches thick, comply with grading shown in the following table:

Rock Grading for 4-inch Thick Layer
Sieve sizes Percentage passing
3 inch 100
2 inch 90–100
1 inch 25–40
3/4 inch 0–10

Granular material must contain at least 90 percent crushed particles when tested under California Test 205.



Shear Stress & Permissible Velocity

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HEC-15 Section 3.1 & HDM Index 864.2

Shear Stress Equation

The maximum shear stress is given by:

τ = γ⋅Hn⋅S

where:

  • τ = shear stress in channel at maximum depth (N/m2 or psf)
  • γ = unit weight of water
  • Hn = depth of flow in channel (ft or m)
  • S = channel bottom slope
Table 865.2 Permissible Shear and Velocity for Selected Lining Materials
Boundary Category Boundary Type Permissible Shear Stress (lb/ft2) Permissible Velocity (ft/s)
Soils(1) Fine colloidal sand 0.03 1.5
Sandy loam (noncolloidal) 0.04 1.75
Clayey sands (cohesive, PI ≥ 10) 0.095 2.6
Inorganic silts (cohesive, PI ≥ 10) 0.11 2.7
Silty Sands (cohesive, PI ≥ 10) 0.072 2.4
Alluvial silt (noncolloidal) 0.05 2
Silty loam (noncolloidal) 0.05 2.25
Finer than course sand – D75 < 0.05 in. (non-cohesive) 0.02 1.3
Firm loam 0.075 2.5
Fine gravels 0.075 2.5
Fine gravel (non-cohesive, D75 = 0.3 in, PI<10) 0.12 2.8
Gravel (D75 = 0.6 in) (non-cohesive, D75 = 0.6 in, PI<10) 0.24 3.7
Inorganic clays (cohesive, PI ≥ 20) 0.14 2.9
Stiff clay 0.25 4.5
Alluvial silt (colloidal) 0.25 3.75
Graded loam to cobbles 0.38 3.75
Graded silts to cobbles 0.43 4
Shales and hardpan 0.67 6
Vegetation Class A turf (Table 4.1, HEC No. 15) 3.7 8
Class B turf (Table 4.1, HEC No. 15) 2.1 7
Class C turf (Table 4.1, HEC No. 15) 1 3.5
Long native grasses 1.7 6
Short native and bunch grass 0.95 4
Rolled Erosion Control Products (RECPs)
Temporary Degradable Erosion Control Blankets (ECBs) Single net straw 1.65 3
Double net coconut/straw blend 1.75 6
Double net shredded wood 1.75 6
Open Weave Textile (OWT) Jute 0.45 2.5
Coconut fiber 2.25 4
Vegetated coconut fiber 8 9.5
Straw with net 1.65 3
Non Degradable Turf Reinforcement Mats (TRMs) Unvegetated 3 7
Partially established 6 12
Fully vegetated 8 12
Rock Slope Protection, Cellular Confinement and Concrete
Rock Slope Protection Small-Rock Slope Protection
(4-inch Thick Layer)		 0.8 6
Small-Rock Slope Protection
(7-inch Thick Layer)		 2 8
No. 2 2.5 10
Facing 5 12
Gabions Gabions 6.3 12
Cellular Confinement:
Vegetated infill		 71 in2 cell and TRM 11.6 12
Cellular Confinement: Aggregate Infill 1.14 – in. D50 (45 in2 cell) 6.9 12
3.5” D50 (45 in2 cell) 15.1 11.5
1.14” D50 (71 in2 cell) 13.2 12
3.5” D50 (71 in2 cell) 18 11.7
1.14” D50 (187 in2 cell) 10.92 12
3.5” D50 (187 in2 cell) 10.55 12
Cellular Confinement:
Concrete Infill		 (71 in2 cell) 2 12
Hard Surfacing Concrete 12.5 12


Trapezoidal Channel: Manning’s n

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Caltrans Highway Design Manual

Commonly accepted values for Manning’s roughness coefficient are provided in Table 866.3A. The tabulated values take into account deterioration of the channel lining surface, distortion of the grade line due to unequal settlement, construction joints and normal surface irregularities. These average values should be modified to satisfy any foreseeable abnormal conditions (Reference: Caltrans Highway Design Manual Index 866.3(3)).
Table 866.3A Average Values for Manning’s n
Type of Channel n value
Unlined Channels:
  Clay Loam 0.023
  Sand 0.020
  Gravel 0.030
  Rock 0.040
Lined Channels:
  Portland Cement Concrete 0.014
  Sand 0.020
  Gravel 0.030
  Rock 0.040
Lined Channels:
  Portland Cement Concrete 0.014
  Air Blown Mortar (troweled) 0.012
  Air Blown Mortar (untroweled) 0.016
  Air Blown Mortar (roughened) 0.025
  Asphalt Concrete 0.016 – 0.018
  Sacked Concrete 0.025
Pavement and Gutters:
  Portland Cement Concrete 0.013 – 0.015
  Hot Mix Asphalt Concrete 0.016 – 0.018
Depressed Medians:
  Earth (without growth) 0.016 – 0.025
  Earth (with growth) 0.05
  Gravel (d50 = 1 in. flow depth < 6 in.) 0.040
  Gravel (d50 = 2 in. flow depth < 6 in.) 0.056
NOTES:
  For additional values of n, see HEC No. 15, Tables 2.1 and 2.2, and “Introduction to Highway Hydraulics”, Hydraulic Design Series No. 4, FHWA Table 14. (No such table. Table B-2 provides n values.)

HEC-15

Section 2.1.3 Resistance to Flow

For rigid channel lining types, Manning’s roughness coefficient, n, is approximately constant. However, for very shallow flows the roughness coefficient will increase slightly. (Very shallow is defined where the height of the roughness is about one-tenth of the flow depth or more.)

For a riprap lining, the flow depth in small channels may be only a few times greater than the diameter of the mean riprap size. In this case, use of a constant n value is not acceptable and consideration of the shallow flow depth should be made by using a higher n value.

Tables 2.1 and 2.2 provide typical examples of n values of various lining materials. Table 2.1 summarizes linings for which the n value is dependent on flow depth as well as the specific properties of the material. Values for rolled erosion control products (RECPs) are presented to give a rough estimate of roughness for the three different classes of products. Although there is a wide range of RECPs available, jute net, curled wood mat, and synthetic mat are examples of open-weave textiles, erosion control blankets, and turf reinforcement mats, respectively. Chapter 5 contains more detail on roughness for RECPs.

Table 2.2 presents typical values for the stone linings: riprap, cobbles, and gravels. These are highly depth-dependent for roadside channel applications. More in-depth lining-specific information on roughness is provided in Chapter 6. Roughness guidance for vegetative and gabion mattress linings is in Chapters 4 and 7, respectively.

Table 2.1. Typical Roughness Coefficients for Selected Linings
  Manning’s n1
Lining Category2 Lining Type Maximum Typical Minimum
Rigid Concrete 0.015 0.013 0.011
Grouted Riprap 0.040 0.030 0.028
Stone Masonry 0.042 0.032 0.030
Soil Cement 0.025 0.022 0.020
Asphalt 0.018 0.016 0.016
Unlined Bare Soil 0.025 0.020 0.016
Rock Cut (smooth, uniform) 0.045 0.035 0.025
RECP Open-weave textile 0.028 0.025 0.022
Erosion control blankets 0.045 0.035 0.028
Turf reinforement mat 0.036 0.030 0.024
1Based on data from Kouwen, et al. (1980), Cox, et al. (1970), McWhorter, et al. (1968) and Thibodeaux (1968).
2Minimum value accounts for grain roughness. Typical and maximum values incorporate varying degrees of form roughness.
Table 2.2. Typical Roughness Coefficients for Riprap, Cobble, and Gravel Linings
  Manning’s n for Selected Flow Depths1
Lining Category Lining Type 0.15 m (0.5 ft) 0.50 m (1.6 ft) 1.0 m (3.3 ft)
Gravel Mulch D50 = 25 mm (1 in.) 0.040 0.033 0.031
D50 = 50 mm (2 in.) 0.056 0.042 0.038
Cobbles D50 = 0.1 m (0.33 ft) –2 0.055 0.047
Rock Riprap D50 = 0.15 m (0.5 ft) –2 0.069 0.056
D50 = 0.1 m (0.33 ft) –2 –2 0.080
1Based on Equation 6.1 (Blodgett and McConaughy, 1985). Manning’s n estimated assuming a trapezoidal channel with 1:3 side slopes and 0.6 m (2 ft) bottom width.
2Shallow relative depth (average depth to D50 ratio less than 1.5) requires use of Equation 6.2 (Bathurst, et al., 1981) and is slope-dependent. See Section 6.1.


Caltrans AVSF Volumes

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Circular Pipe: Manning’s n

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Caltrans HDM Table 851.2

Suggested values for Manning’s Roughness coefficient (n) for design purposes are given in the tabe below.

Manning “n” Value for Alternative Pipe Materials(1)
Type of Conduit Recommended Design Value “n” Value Range
Corrugated Metal Pipe(2)
(Annular and Helical)(3)
2⅔” x ½” corrugation 0.025 0.022 – 0.027
3″ x 1″ “ 0.028 0.027 – 0.028
5″ x 1″ “ 0.026 0.025 – 0.026
6″ x 2″ “ 0.035 0.033 – 0.035
9″ x 2½” “ 0.035 0.033 – 0.037
Concrete Pipe
Pre-cast 0.012 0.011 – 0.017
Cast-in-place 0.013 0.012 – 0.017
Concrete Box 0.013 0.012 – 0.018
Plastic Pipe (HDPE and PVC)
Smooth Interior 0.012 0.010 – 0.013
Corrugated Interior 0.022 0.020 – 0.025
Spiral Rib Metal Pipe
¾” (W) x 1″ (D) @ 11½” o/c 0.013 0.011 – 0.015
¾” (W) x Ÿ” (D) @ 7½” o/c 0.013 0.012 – 0.015
¾” (W) x 1″ (D) @ 8½” o/c 0.013 0.012 – 0.015
Composite Steel Spiral Rib Pipe 0.012 0.011 – 0.015
Steel Pipe, Ungalvanized 0.015 —
Cast Iron Pipe 0.015 —
Clay Sewer Pipe 0.013 —
Polymer Concrete Grated Line Drain 0.011 0.010 – 0.013
Notes:  
(1) Tabulated n-values apply to circular pipes flowing full except for the grated line drain. See Note 5.
(2) For lined corrugated metal pipe, a composite roughness coefficient may be computed using the procedures outlined in the HDS No. 5, Hydraulic Design of Highway Culverts.
(3) Lower n-values may be possible for helical pipe under specific flow conditions (refer to FHWA’s publication Hydraulic Flow Resistance Factors for Corrugated Metal Conduits), but in general, it is recommended that the tabulated n-value be used for both annular and helical corrugated pipes.
(4) For culverts operating under inlet control, barrel roughness does not impact the headwater. For culverts operating under outlet control barrel roughness is a significant factor. See Index 825.2 Culvert Flow.
(5)  Grated Line Drain details are shown in Standard Plan D98C and described under Index 837.2(6) Grated Line Drains. This type of inlet can be used as an alternative at the locations described under Index 837.2(5) Slotted Drains. The carrying capacity is less than 18-inch slotted (pipe) drains.

HDS-4 Table B-3

Manning’s n Values for Closed Conduits
Description Manning’s n Range
Concrete pipe 0.011 – 0.013
Corrugated metal pipe or pipe-arch:
Corrugated Metal Pipes and Boxes, Annular or Helical Pipe (Manning’s n varies with barrel size) 68 by 13 mm (2⅔ x ½ in.) corrugations 0.022 – 0.027
150 by 25 mm (6 x 1 in.) corrugations 0.022 – 0.025
125 by 25 mm (5 x 1in.) corrugations 0.025 – 0.026
75 by 25 mm (3 x 1 in) corrugations 0.027 – 0.028
150 by 50 mm (6 x 2 in.) structural plate corrugations 0.033 – 0.035
230 by 64 mm (9 x 2-1/2 in.) structural plate corrugations 0.033 – 0.037
Corrugated Metal Pipes Helical Corrugations, Full Circular Flow 68 by 13 mm (2⅔ x ½ in.) corrugations 0.012 – 0.024
Spiral Rib Metal Pipe Smooth walls 0.012 – 0.013
Vitrified clay pipe 0.012 – 0.014
Cast-iron pipe, uncoated 0.013
Steel pipe 0.009 – 0.013
Brick 0.014 – 0.017
Monolithic concrete:
1. Wood forms, rough 0.015 – 0.017
2. Wood forms, smooth 0.012 – 0.014
3. Steel forms 0.012 – 0.013
Cemented rubble masonry walls:
1. Concrete floor and top 0.017 – 0.022
2. Natural floor 0.019 – 0.025
Laminated treated wood 0.015 – 0.017
Vitrified clay liner plates 0.015

NOTE: The values indicated in this table are recommended Manning’s n design values. Actual field values for older existing pipelines may vary depending on the effects of abrasion, corrosion, deflection, and joint conditions. Concrete pipe with poor joints and deteriorated walls may have n values of 0.014 to 0.018. Corrugated metal pipe with joint and wall problems may also have higher n values, and in addition, may experience shape changes which could adversely effect the general hydraulic characteristics of the pipeline.

Other: Variation of n with Flow Depth in Pipe

From “Scattergraph’s Principles and Practice, by Kevin L Enfinger, P.E. and James S Schutsbach, ADS Environmental Services, 2003.

A fourth order polynomial approximation of Camp’s varying roughness coefficient:

f(d)=1.04+2.30*(d/D)-6.86*(d/D)2+7.79*(d/D)3-3.27*(d/D)4

From http://www.engineeringexceltemplates.com, Manning Equation Partially Filled Circular Pipes:

The Manning equation was developed for flow in open channels with rectangular, trapezoidal, and similar cross-sections. It works very well for those applications using a constant value for the Manning roughness coefficient, n. Better agreement with experimental measurements is obtained for partially full pipe flow, however, by using the variation in Manning roughness coefficient developed by Camp …

The equations to calculate n/nfull, in terms of (y/D) for y < (D/2) are as follows:>/p>

  • n/nfull = 1 + (y/D)*(1/3) for 0 < (y/D) < 0.03
  • n/nfull = 1.1 + ((y/D) – 0.03)*(12/7) for 0.03 < y/D < 0.1
  • n/nfull = 1.22 + ((y/D) – 0.1)*(0.6) for 0.1 < (y/D) < 0.2
  • n/nfull = 1.29 for 0.2 < (y/D) < 0.3
  • n/nfull = 1.29 – ((y/D) – 0.3)*(0.2) for 0.3 < (y/D) < 0.5

The equation used for n/nfull for 0.5 < (y/D) < 1 is:

  • n/nfull = 1.25 – [((y/D) – 0.5)/2]


Caltrans New Riprap Classes

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Source: Caltran Highway Design Manual, Chapter 870
These supersede the previous Caltrans Riprap Sizes.

Caltrans requires the use of these new RSP gradations starting August 1st, 2016 in new projects and those not yet at 30 percent PS&E stage.

Caltrans Highway Design Manual Table 873.3A

RSP Class by Median Particle Size(3)
Nominal RSP Class by Median Particle Size(3) d15 d50 d100 Placement
Class (1), (2) Size (in) Min Max Min Max Max Method
I 6 3.7 5.2 5.7 6.9 12.0 B
II 9 5.5 7.8 8.5 10.5 18.0 B
III 12 7.3 10.5 11.5 14.0 24.0 B
IV 15 9.2 13.0 14.5 17.5 30.0 B
V 18 11.0 15.5 17.0 20.5 36.0 B
VI 21 13.0 18.5 20.0 24.0 42.0 A or B
VII 24 14.5 21.0 23.0 27.5 48.0 A or B
VIII 30 18.5 26.0 28.5 34.5 48.0 A or B
IX 36 22.0 31.5 34.0 41.5 52.8 A
X 42 25.5 36.5 40.0 48.5 60.5 A
XI 46 28.0 39.4 43.7 53.1 66.6 A

NOTES:

  1. Rock grading and quality requirements per Standard Specifications.

  2. RSP-fabric Type of geotextile and quality requirements per Section 96 Rock Slope Protection Fabric of the Standard Specifications. For RSP Classes I thru VIII, use Class 8 RSP-fabric which has lower weight per unit area and it also has lower toughness (tensile x elongation, both at break) than Class 10 RSP-fabric. For RSP Classes IX thru XI, use Class 10 RSP-fabric.

  3. Intermediate, or B dimension (i.e., width) where A dimension is length, and C dimension is thickness.

Caltrans Highway Design Manual Table 873.3B

RSP Class by Median Particle Weight(3)

Nominal RSP Class by Median Particle Weight W15 W50 W100 Placement
Class (1), (2) Weight Min Max Min Max Max Method
I 20 lb 4 11 15 27 140 B
II 60 lb 14 39 50 94 470 B
III 150 lb 32 94 120 220 1,100 B
IV 300 lb 63 180 250 440 2,200 B
V 1/4 ton 110 300 400 700 3,800 B
VI 3/8 ton 180 520 650 1,100 6,000 A or B
VII 1/2 ton 250 750 1000 1,700 9,000 A or B
VIII 1 ton 520 1,450 1,900 3,300 9,000 A or B
IX 2 ton 870 2,500 3,200 5,800 12,000 A
X 3 ton 1,350 4,000 5,200 9,300 18,000 A
XI 4 ton 1,800 5,000 6,800 12,200 24,000 A

NOTES:

  1. Rock grading and quality requirements per Standard Specifications.
  2. RSP-fabric Type of geotextile and quality requirements per Section 96 Rock Slope Protection Fabric of the Standard Specifications. For RSP Classes I thru VIII, use Class 8 RSP-fabric which has lower weight per unit area and it also has lower toughness (tensile x elongation, both at break) than Class 10 RSP-fabric. For RSP Classes IX thru XI, use Class 10 RSP-fabric.
  3. Values shown are based on Table 873.3A dimensions and an assumed specific gravity of 2.65. Weight will vary based on density of rock available for the project.