Accession Number:

AD0773018

Title:

Ground Support Prediction Model (RSR Concept)

Descriptive Note:

Final rept.

Corporate Author:

JACOBS ASSOCIATES INC SAN FRANCISCO CA

Personal Author(s):

• Wickham, George E.
• Tiedemann, Henry R.

Report Date:

1974-01-01

Pagination or Media Count:

272.0

Abstract:

A methodology is described for predicting rock tunnel support requirements in the pre-construction period, based on geologic investigation, and construction factors such as size and shape of opening, direction of drive and method of excavation to be employed. Development of this method, known as the Rock Structure Rating RSR concept, was based on a case history study approach, using data from 33 tunnel projects to develop a tentative prediction model. The Rock Structure Rating is a measure of the ability of a rock mass to support itself around a given tunnel opening by assigning weighted ratings to important geologic and construction factors affecting this ability. Development of a modified and expanded prediction model is described based on additional research. The resulting revised prediction model was used to predict support requirements for six on-going tunnel projects and verification of actual supports used, made by field site visits where possible. Results of these field investigations are given and analyzed.

Descriptors:

• *EXCAVATION
• *SUPPORTS
• *TUNNELS
• FORECASTING
• MINING ENGINEERING
• OPENINGS
• ROCK MECHANICS
• UNDERGROUND

Subject Categories:

• Mining Engineering
• Soil Mechanics
• Civil Engineering

Distribution Statement:

APPROVED FOR PUBLIC RELEASE