Large Deformation Of Long-distance Pipeline Design Theoretical Research

This paper belongs to the project of preeminent youth fund of si chuan province (No. 03ZQ026-044) "The design and choice of special well tubal and pipelines ",and is a part of it.The damnification of long pipelines caused by large deformation is a big part of domestic and foreign invalidation accidents of long pipelines, and is an important factor of invalidation for long pipelines. There is little domestic investigation on long pipelines' intensity design theory and criterion, and most is refered to foreign design criterion. So, it's very necessary and important to study the theory of large deformation design and make essential corrections to domestic criterions.This paper studies long pipelines' several typical lage deformation behaviors by geomechanics, soil and solid mechanics and compute the created models by the way of elasticity and plastic theory and computer emulation, and establish systemic large deformation analysis theory and research method of long pipelines, and results are:(1) Establish the large defaormation of original up-protruding bend pipelines and bring forward several suggestions on the security of critical axial force calculation etc. in active criterions.(2) Establish the horizontal elbow'deformation formulas under the bilinear model, Winkler model etc.; simulate and validate these formulas; put forward some suggestions on intensity check method of bend in active criterions.(3) Establish large deformation model of pipes under geologic disasters such as collapse and gulch; simulate and validate these formulas, and make certain of pipe' lapse length, and put forward some defendable suggestions.(4) Establish large deformation model of pipeline span, simulate and validate these formulas; give ideas on the set of frusta; put forward several suggestions on correlative criterions.(5) Make primary research on the design of compensator, and establish the calculation models of compensator's position and absorbed displacement; contrast and make some corrections to the intensity design of compensator in active criterions.