The value of friction coefficient F should be determined by several groups of tests. The final selection should be based on the results of field and indoor tests, combined with the actual situation of the site, and referring to the experience of similar geological conditions of the existing projects. According to the statistical data of existing projects at home and abroad, the F value between concrete and bedrock is usually between 0.5 and 0.8. The project is adopted according to schedule 2, taking f = 0.65.