To reveal the mechanism of karst collapse induced by groundwater pumping,the authors analyse the expanding condition of soil cavity by analytical method and put forward the concept of spalling force.

For the purpose of the study of mechanism of karst collapse induced by pumping,the conditions of soil cavity expanding are analyzed by analytical method,and the concept of spalling force is put forward.

Discussion on methods of calculating peeling-off stress in midspan of RC beams strengthened with FRP sheets;

The factors influencing peeling-off failure and failure criterion are summarized,and the characteristics of several methods for calculating the peeling-off stress are discussed.

Analysis of the peeling stress at the end of the reinforced concrete beam with prestressed carbon fiber reinforced polymer sheet;

Based on the linear elastic theory, this paper presents a method for calculating the peeling stress at the sheeting end of a RC beam with a strengthening sheeting under linear distributed loads.

The characteristics of distribution of the shearing stresses,as well as normal and peeling stresses which influence the quality of bonded wafers are discussed.

With regard to the RC beams strengthened by bonding steel sheet against the action of concentrated and evenly distributed load, an analysis is made on the factors influencing maximal normal stress against peeling of steel sheet.