Research conclusions: The analysis showed that the mortar existing in this area was caused by casting the concrete to the pile by two times. The concrete could be casted to the one pile by one time. At the same time，the casting of concrete to the pile could be continuous and the stratification of more than Im could be avoided. The vibration rods would be used for the hierarchical compaction. Additionally, more attention would be paid to the construction quality of the remaining wall and the concrete slump would be controlled at 180 mm. It would make sure that there was no sediment on the pile bottom and there was no water leakage of the remaining wall. If it was necessary to cast the concrete for the second time, the second integrity test to the pile would be done to ensure that there was no mortar on the pile top casted by the first time. For the cutting subgrade, the anti-slide piles would be completed before excavation of the subgrade. For the same row of the pile, the interval construction was needed. In the process of the construction, the second batch of the interval piles could not be casted until the 28 days later after the first batch of the piles were casted.