During splicing, the old subgrade s

During splicing, the old subgrade slope should be excavated into steps, so as to strengthen the connection between the new and old subgrade and promote the coordinated deformation between the new and old subgrade. In the process of bench excavation, the bench width is generally not less than two meters, so as to meet the construction needs of paving and compaction. When restricted by special conditions, the slope shall be excavated to an inward slope, and the width of steps shall not be less than one meter. At the same time, in order to enhance the connection and integrity between the new and old subgrade, geogrid should also be laid.