Source: https://www.quantsurv.com/sectors/transportation/tunnels
Content format: Markdown version of the public page.
Content reviewed: 2026-10-13

# Tunnels

Quantity surveying and claims support for tunnel construction, associated civil works and installation packages.

## Commercial challenges and how we approach them

Tunnel construction brings excavation and structural works together with shafts, access and internal installations. Packages can use different measurement and payment arrangements. The account needs clear boundaries between the tunnelling work, surface assets and separately appointed services.

### Ground conditions against the contractual baseline

#### The Challenge

Rock, mixed ground and groundwater can change excavation and support requirements. A slower advance is not by itself evidence that the contract entitles either party to a price adjustment.

#### Our approach

We start with the ground baseline and the contract's allocation of risk. Face logs, investigation results and specialist findings establish what was encountered; instructions establish what changed. From there, we assess quantities, support requirements and productivity separately. Slower advance alone does not establish entitlement, and an unforeseen condition does not automatically make every later tunnelling cost recoverable.

### Excavation support and lining changes

#### The Challenge

A revised support class can change bolts, reinforcement, concrete and the excavation cycle. A rate per metre may conceal those differences.

#### Our approach

We reconcile the authorised support records with the measured work and rate build-ups. Additional cycle resources are assessed separately where justified, avoiding overlap between the valuation and a disruption claim.

### Spoil handling and disposal capacity

#### The Challenge

Excavated material must pass through a constrained logistics system. Different material properties, treatment requirements or disposal routes can affect handling, storage and the continuity of tunnelling.

#### Our approach

We trace the changed material from excavation to its authorised destination, using classifications, movement records and disposal evidence. This tests the additional handling and haulage against the removal cost already included.

### Shafts, launch sites and workfront readiness

#### The Challenge

The tunnelling team may be mobilised before a shaft, power supply or launch arrangement is ready. High plant costs can begin before the first metre is excavated.

#### Our approach

We compare enabling-package commitments with tunnelling mobilisation dates. Actual readiness and resource records support an assessment of standby, preservation and resequencing under the relevant contract.

### Monitoring triggers and adjacent assets

#### The Challenge

Settlement or movement monitoring may require additional treatment, changed methods or a pause near sensitive structures. The commercial effect depends on the technical instruction and the risk already included in the contract.

#### Our approach

We connect the monitoring result to the technical instruction and the work affected. An extra treatment, altered method and instructed pause have different cost consequences and may engage different contract provisions. Our role is to assess those consequences from the records; decisions about the necessary engineering response remain with the responsible specialists.

### Fit-out and integrated safety-system testing

#### The Challenge

Excavation is only part of an operational transport tunnel. Ventilation, controls, services and integrated testing can determine when it is actually ready to open.

#### Our approach

We reconcile the fit-out boundaries and acceptance dependencies before award. Additional commissioning and temporary arrangements are assessed against actual readiness, instructions and the original test scope.