Research on crack grouting in concrete dams

It is common that concrete dams occur cracks in construction or operation.In order to operate safely,grouting is always adopted as the treatment for some harmful cracks.In this paper,the four aspects are considered for overall evaluations of crack grouting.First,by the recognition of causes and characteristics as well as the harm of cracks,the grouting principle is examined whether the grouting materials can meet the requirements.Second,the grouting is evaluated from grouting technology and the measures of quality-control.Third,the core samples of grouting obtained along the cracks are tested for mechanics properties so as to get the real behaviors of tensile strength and water-proof.Fourth,by 3D FEM simulation computation of fore-and-aft crack grouting,stability of the whole dam and the mechanics differences of key parts and partial sections of cracks after grouting are analyzed.Finally,the grouting for three big penetrable cracks of Qingtongxia dam is taken for an example to introduce the application of this evaluation,the results show that the evaluations of grouting proposed in this paper can be scientific and objective and can provide the references for crack grouting of other concrete dams and its evaluation.