TCVN 9362:2012 - Foundation Design

What this standard covers

TCVN 9362:2012 is the Vietnamese design standard for building and structure foundations. It covers shallow and general foundation design - bearing capacity, settlement and the soil investigation the design must be based on.

The standard governs how the ground is characterised and how a foundation is proportioned on it: the soil parameters required from a site investigation, the calculation of bearing capacity, and the settlement checks that usually control a shallow foundation on the soft alluvial soils common across much of Vietnam.

Where the ground cannot carry the structure on a shallow foundation, the design moves to piles under TCVN 10304 - which is why the two standards are almost always used together on a substantial project.

What you will find in it

Site investigation

The ground information a foundation design must be based on, and the soil parameters to be taken from it.

Soil classification

Classification of soils and their strength and deformation properties, which set both the bearing capacity and the settlement.

Bearing capacity

The pressure a natural foundation may carry, allowing for footing width and depth, groundwater and the inclination or eccentricity of the load.

Settlement

Calculation of settlement under the design pressure, and the limits on total and differential settlement that the supported structure can tolerate.

Stability

Checks on sliding, overturning and, where the foundation sits on or near a slope, the overall stability of the ground.

Special ground

Treatment of soft, expansive, collapsible and filled ground, where ordinary bearing-capacity rules alone do not give a safe answer.

When to use this standard

Open TCVN 9362 for a shallow or natural foundation - pads, strips and rafts bearing directly on soil. If the structure is founded on piles instead, TCVN 10304 governs. It determines what the ground can carry and how much it will settle; the reinforcement of the footing itself is designed to TCVN 5574.

How it fits with the other standards

Pile foundations are covered separately by TCVN 10304. Loads applied to the foundation come from TCVN 2737, and a concrete footing is designed as a member to TCVN 5574.

What each section covers

Mục 1

Scope. Natural (shallow) foundations for civil and industrial buildings. It explicitly excludes hydraulic works, bridges and roads, airports, PILE foundations and foundations carrying dynamic load - piles go to TCVN 10304.

Mục 2

General provisions: the limit states a foundation must satisfy and the ground information the design has to be based on.

Mục 3

Classification of soils. Naming a soil to this section is what fixes the strength and deformation parameters used everywhere else in the standard.

Mục 4

Foundation design - the core section: bearing capacity, settlement and stability, and the inputs and checks each requires.

Mục 5

Collapsible soils, where wetting causes the structure to lose its skeleton and settle suddenly.

Mục 6

Expansive soils, which heave as well as settle with moisture change.

Mục 7

Saturated peat, highly compressible and slow to consolidate.

Mục 8

Soft mud, common in the Vietnamese delta regions and often the reason a shallow foundation is not viable.

Mục 9

Eluvial soils - weathered residual ground whose properties vary sharply with depth.

Mục 10

Saline soils, where dissolution and aggressive chemistry attack both the ground and the foundation.

Mục 11

Fill, where placement and compaction history govern behaviour more than the parent material does.

Mục 12

Other difficult sites not covered by the preceding sections.

Mục 13

Foundations in seismic regions, used alongside TCVN 9386.

Mục 14

Foundations for overhead transmission-line structures, dominated by uplift and lateral load rather than bearing.

Mục 15

Foundations for bridges and culverts.

Phụ lục A

Normative annex on deriving characteristic and design values of soil properties from test data - the step where most geotechnical judgement is exercised.

Phụ lục B

Informative annex tabulating characteristic strength and deformation properties by soil type, for use when site-specific test data is not available.

Phụ lục C

Informative annex on calculating settlement and deformation of the ground.

Phụ lục D

Informative annex giving conventional allowable bearing pressures, useful for preliminary sizing.

Phụ lục E

Normative annex giving the coefficients used in the bearing-capacity calculation of Mục 4.

Related standards

Tools that implement this standard