Discussion on Causes of Abnormal Bearing Capacity of Post Grouting at Pile End

The bearing capacity of post grouting piles in deep soft soil layers is influenced by multiple factors. Taking three sets of post grouting piles at the pile end of a certain project in Shanghai as the research object, the influencing factors on the bearing capacity of post grouting piles were investigated, with the ninth layer of silt layer as the bearing layer of the pile foundation. The results indicated that the bearing capacity of post grouting piles was greatly influenced by the drilling process, grouting process, and sediment thickness. To avoid the influence of the above factors, the reverse circulation drilling and circulation mud sand removal construction technology were adopted, and the structure of the grouting hole was improved. The use of alternating high and low pressure grouting significantly increased the grouting amount, effectively cemented the sediment at the bottom of the hole, and solved the problem of insufficient bearing capacity of grouting pile in the area.