Mechanical Analysis of Vaulted Expansion of Semi-rigid Base

Abstract

Vaulted expansion of semi-rigid base caused by thermal stress was analyzed with the theory of buckling of columns in mechanics of materials and the theory of buckling of elastic plates in mechanics of elasticity. Whether vaulted expansion of semi-rigid base will happens was judged by comparing the thermal stress and critical stress calculated with the two theories respectively. Several technical parameters which influence the thermal stress were analyzed and suitable values of them in construction were recommended. The result indicates that (1) the calculation results are coincident, however result computed with the theory of buckling of column is prone to be more conservative; (2) in order to avoid the failure caused by vaulted expansion in semi-rigid base, construction in winter should be avoid, and the difference in temperature during construction should he as low as possible; (3) it is improper for contractors to pursue the excessive high elastic module for semi-rigid base by increasing the content proportion of cement; (4) materials with dense structure of skeleton which has low expansion coefficient should he adopted for semi-rigid base.