scope:

INTRODUCTION

The purpose of this document is to provide background information, design guidance and typical construction methodologies for the application of a Sprayed Concrete Lining Renewal Detail for Masonry Arch Tunnels as part of the suite of Network Rail Standard Tunnel Repair Details as specified in the Standard Detail Drawings NR/CIV/SD/550 to NR/CIV/SD/554 (herein referred to as SD Drawings).

Owing to a wide variety of external factors which can affect the design, it is not practical to produce a standardised Sprayed Concrete Lining Renewal Detail (herein referred to as SCL Detail) which would cover all possible situations. However, the SCL Detail has significant scope for site specific development due to the numerous common design elements which can be easily amended to suit a range of circumstances.

This document provides guidance on the design philosophy, criteria and assumptions adopted in the production of the SCL Detail as shown in the SD Drawings. This information is intended to allow future Scheme Designers to undertake their own assessment of the individual circumstances to which the SCL Detail is to be applied and to adapt the design accordingly. Thus they should be aware that some analysis and design will be required in its application in some instances.

This document makes reference to NR/CIV/SD/TUM/520, Technical User Manual for the application of Standard Tunnel Repairs which serves as a useful guide in understanding the possible causes, and available solutions for the repair of typical defects in tunnels.