SQUARE SINGLE AND MULTICELL BOX CULVERTS - SECTION 4 - APRON AND BASE SLAB

Oct 24, 2026

Standard drawing specifies typical cast-in-situ base slabs, aprons and headwalls for precast RC box culverts and slab link box culverts. Applicability is limited to opening heights H=375–600 and reactive soil conditions with linear shrinkage up to 8%. It provides design traffic loading references, minimum reinforcement rules under full restraint, concrete and exposure requirements, blinding concrete, surface roughening and chamfer details. It also includes guidance on base slab redesign options when bearing capacity is inadequate, and requires contraction joints where base slab length or width exceeds 20 m.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages2

Reading Time5 min

AccessFree to download

GENERAL ARRANGEMENT-MULTIPLE CELL RC BOX CULVERT

GENERAL ARRANGEMENT-SLAB LINK BOX CULVERT

TYPICAL DETAILS FOR APRON AND BASE SLAB

GENERAL NOTES:

SECTION A-(

SECTIONDTYPICAL DETAILSFOR APRON ATDETAIL③END OF HEADWALL

# TABLE OF DIMENSIONS CulvertCulvert chainageas specifiedQBase slab forskewed culvert.Refer Drawing 2Crownunits - | Skew
angle
⑦ | Dim for Q and X for
height of opening H | | | | | --- | --- | --- | --- | --- | | | H | 375 | 450 | 600 | | 0-10 | Q | 600 | 750 | 900 | | 11-20 | Q | 600 | 750 | 900 | | | X | 650 | 800 | 000 | | 21-30 | Q | 600 | 750 | 900 | | | X | 700 | 900 | 1100 | | 31-45 | Q | 600 | 750 | 900 | | | X | 800 | 1000 | 1200 | Base slabHolding down anchors, reinforcementminimum number =1.Refer Drawing 2 for Detailsand Installation Notes —Lean mix infill,InvertSpanrefer Detail31-12F·1-12A·Starter bars atends of headwall-eHeadwallLmit of bose slobApron.Refer Note 6-Base referencefor surface finish andDrawing 2 for details135pointL1-12A g 12A along skew with eachCut off wall.Apron reinforcementmesh layer.Refer Section ARefer Drawing 2一on Drowing 2TYPICAL PLAN-HIGH SKEW DRAWNMULTICELL BOX CULVERT SHOWNSKEWED SINGLE AND SLAB LINK BOX CULVERTS SIMILAR # SQUARE SINGLE AND MULTICELL BOX CULVERTS SIMILAR TYPICAL ELEVATION-SPANNING SLAB DETAILS ## TYPICAL ELEVATION-MULTICELL DETAILS # GENERAL ARRANGEMENT-MULTIPLE CELL RC BOX CULVERT GENERAL ARRANGEMENT-SLAB LINK BOX CULVERT 250 25 chamfer Headwall 7不 (250) 9 ◎ 200 米 12 dia bars to suit skew, refer PLANS Refer drawing 2 for dowel and Box culvert reinforcement details- crown unit Limit of Apron.Refer Note 6 base slab for surface finish- Culvert invert Base slab ④ N min 600 This face shall- be coated with 50 blinding concrete SECTIONDTYPICAL DETAILSFOR APRON ATDETAIL③END OF HEADWALL bitumen Cut off wall Z ④ ## TYPICAL DETAILS FOR A-( # SECTION4 APRON AND BASE SLAB | The purpose of this Standard Drawing is to provide typical standard details
that shall be used within the limtations specified n the drawing and in
accordance with the following:
1.The adaptability of the standard details shll be assessed by the project
designer n respect of specific project geometric,appropriate foundation
and scour conditions.
2.In reactive soils:this standard drawing s only applicable for reactive soils
with linear shrinkage up to 8%.Specialist geotechnical design advice shall
be sought otherwise.
3.If the insitu bearing capacity is inadequate,the following options may be
explored subject to review and acceptance by E&T Structures and
Geotechnical sections:
a.Insitu ground improvemen,and/or
b.Redesign of the base slab.
Any redesign works shall be RPEQ certified by appropriate engineering
disciplines for compliance.
4.When there is uncertainty regarding the application of the standard details
on this drawing for a specific project,advice shall be sought from E&T
Structures. | | --- | ## GENERAL NOTES: 1.SCOPE:This drowing is to detail cast insitu base slab,aprons and headwalls forprecast R C Box Culverts and Slab Link Box Culverts where H(height of opening)=375 to 600.This drawing supersedes Standard Drawings 1174 and 1317.This drawing does not provide details of fish passage requirements.Where projectspecific environmental assessment determines that waterway barrier works arerequired,additional details shall be developed and included in the project drawings. 2.BOX CULVERTS shall be constructed in accordance with MRTSO3. 3.DESIGN TRAFFIC LOADING:HLP400,M1600,A160 and W80 are in accordance withAS 5100.2. Maximum height of illover he culvert shall be 2000.Maximum design pressure(Ea)under the culvert slab bases are provided in theBase Slab Details and Dimensions table on drawing 2. 4.DOWELLED CONTRACTION JOINTS shall be provided where (a)the length and/or (b)thewidth of the base slab exceed 20m.When contraction joints are required across thewidth,they shall be located at 1/4 span points of crown units

FAQs

What range of opening height H does the standard drawing cover?

It applies where the height of opening H is 375 to 600.

When are dowelled contraction joints required for the base slab?

Contraction joints are required when the base slab length and/or width exceeds 20 m, with joints located at 1/4 span points of crown units and continued across aprons.

What soil condition limits the applicability of the standard details?

The standard details are only applicable for reactive soils with linear shrinkage up to 8%; otherwise, specialist geotechnical design advice is required.

Oct 24, 2026

Upload by Sophia Brooks