Filed Comparative Investigation of Loading Test on Micro-Piles Installed with Different Technique – (Case Study)

Abstract

Foundation can be subjected to additional load and constructed in soft soils; therefore, the settlement or foundation tilting is achieved. The most beneficial method to control the settlement and foundation tilting are to be used Micro-piles which have been considered is an effective and easy to reinforce the existing foundation, it also successfully adopted in many ground improvement techniques to safeguard structure from collapse. The paper aims to study the behavior of full-scale micro piles under compression in the filed with length of 20 m as end bearing with diameter of 88.9 mm. This study is focused on the observing the behavior of three micro-piles installed with different technique. The first is normal one without injection as pipe piles MP1, the second is pipe pile with grouted bulb MP2 only under the toe of micro-piles and inside grouting. The last one or third micro-pile MP3 is pipe pile with fully injection for both toe and around the pile length. Three loading tests in the field are carried out to show the load settlement response under axial compression and horizontal load to get the ultimate micro-pile capacity. The results showed that the fully injected micro-piles with grouting have a higher ultimate load capacity and minor settlement compared with other two cases. The ultimate load capacities for fully grouted micro-piles and only with grouted bulb are found to be 13 and 8 times of ultimate capacity of pipe micro-piles without grouted bulb at the toe respectively. Also, it is found that the ultimate horizontal load capacity of Mp3 is found to be 27 ton while it is recorded as 3 and 4 ton for MP1 and MP3 respectively at horizontal displacement of 0.2 micro-pile diameter.