Computer models to support investigations of surface subsidence and associated ground motion induced by underground coal gasification

Technical Report · Sat Aug 01 04:00:00 EDT 1981

OSTI ID:5863426

Trent, B C; Langland, R T

Two computer codes compare surface subsidence induced by underground coal gasification at Hoe Creek, Wyoming, and Centralia, Washington. Calculations with the STEALTH explicit finite-difference code are shown to match equivalent, implicit finite-element method solutions for the removal of underground material. Effects of removing roof material, varying elastic constants, investigating thermal shrinkage, and burning multiple coal seams are studied. A coupled, finite-difference continuum rigid-block caving code is used to model underground opening behavior. Numerical techniques agree qualitatively with empirical studies but, so far, underpredict ground surface displacement. The two methods, numerical and empirical, are most effective when used together. It is recommended that the thermal characteristics of coal measure rock be investigated and that additional calculations be carried out to longer times so that cooling influences can be modeled.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5863426
• Report Number(s): UCRL-53029; ON: DE82004936
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
010404 -- Coal
Lignite
& Peat-- Gasification
010900* -- Coal
Lignite
& Peat-- Environmental Aspects
COAL GASIFICATION
COMPUTER CODES
ENVIRONMENTAL IMPACTS
FINITE DIFFERENCE METHOD
GASIFICATION
GROUND SUBSIDENCE
IN-SITU GASIFICATION
IN-SITU PROCESSING
ITERATIVE METHODS
NUMERICAL SOLUTION
PROCESSING
THERMOCHEMICAL PROCESSES