Bridge Span Load Test
(Structural Load Test)

Static and dynamic load testing of bridge spans to verify structural adequacy, measure actual deflections and assess load distribution behaviour — mandatory for bridge commissioning and safety assessment.

Overview

What is the Bridge Span Load Test?

The Bridge Span Load Test applies controlled static loads (typically using loaded trucks or kentledge) to a bridge span while measuring deflections, strains and crack widths at critical locations. The measured responses are compared against theoretical predictions to verify structural performance.

Conducted as per IRC 112 and IRC 6, bridge load tests are mandatory for commissioning of new bridges and periodic safety assessment of existing bridges. Global Lab conducts bridge load tests for prestressed concrete, steel and composite bridges using NABL-calibrated LVDTs, strain gauges and total stations.

Mandatory Commissioning Test

Required by IRC before opening new bridges to public traffic.

Deflection Measurement

Precise mid-span and quarter-span deflection measured using LVDTs and total stations.

Strain Measurement

Strain gauges on critical sections verify stress levels against design predictions.

Dynamic Load Testing

Moving load tests assess impact factor and dynamic amplification of the bridge.

NABL Certified Reports

All results issued on NABL-accredited letterhead per IRC 112/IRC 6.

All Bridge Types

PSC, steel, composite and RCC bridges tested per relevant IRC standards.

Test in Action

Bridge Span Load Test — Site Images

Loaded Trucks Positioned on Bridge Span

LVDT Deflection Measurement at Mid-Span

During Load Test

Test Procedure

How the Bridge Span Load Test is Conducted

1

Instrumentation Plan

LVDTs, strain gauges, dial gauges and total station reflectors are installed at pre-determined critical locations on the bridge span.
2

Zero/Datum Reading

Initial zero readings are taken with the bridge under self-weight only before any test load is applied.
3

Static Load Application

Loaded trucks or kentledge are positioned at specified load positions (mid-span, quarter-span) per IRC 112 loading protocol.
4

Deflection and Strain Recording

All instruments are read at each load position. Readings are taken during loading and after load removal (elastic recovery).
5

Comparison and Reporting

Measured deflections and strains are compared against theoretical values. Pass/fail assessment per IRC criteria. NABL report within 7 days.

Standards & Specifications

Applicable Test Standards

Standard	Title	Scope	Type
IRC 112	Code of Practice for Concrete Road Bridges	Bridge Design	IRC
IRC 6	Standard Specifications for Road Bridges — Section II: Loads and Load Combinations	Bridge Loading	IRC
IS 456:2000	Plain and Reinforced Concrete — Code of Practice	RCC Bridges	Indian Standard
IRC SP 37	Guidelines for Evaluation of Load Carrying Capacity of Bridges	Bridge Assessment	IRC

Applications

Where is the CAPO Test Used?

Commissioning of new road bridges before opening to public traffic

Periodic safety assessment of aging bridges under NHAI and state PWD

Assessment of bridges after major repair, widening or strengthening works

Investigation of bridges showing excessive deflection, cracking or vibration

Rating of bridges for permit loads heavier than design traffic

Forensic investigation after bridge accidents or unusual loading events

Why Choose Global Lab

Our Advantages

NABL Accredited ReportsIRC and government-accepted certificates for bridge commissioning.

Complete InstrumentationLVDTs, strain gauges, total station and dynamic sensors for comprehensive testing.

Autovity Digital ReportsDeflection and strain data accessible digitally with graphical reports.

IRC ExpertiseExperienced in bridge load testing for NHAI, Railways and state PWD projects.

Pan-India CoverageTeams deployed across 7 lab locations for rapid mobilisation to bridge sites.

Structural Health MonitoringPost-test SHM systems installed for continuous bridge monitoring.

Bridge Span Load Test(Structural Load Test)