Abstract

GIS 150 KV Tambak Lorok III Semarang is a coastal area, stabilization is carried out with piles to reduce land subsidence in the area. In the piling process the soil grains are forced vertically and laterally when the pile foundation is driven into the ground, thus increasing the water pressure in the soil pore system. Nearby buildings will be affected and may suffer damage. The pile driving location for the GIS 150 KV Tambak Lorok III Semarang project is adjacent to other structures. So, the amount of land that needs to be cleared around the project must be calculated. This study uses methodology that makes theoretical predictions about the magnitude of heave caused by piles. Subsequently, vertical ground movement measurements made using the Finite Element Method (Plaxis Program) were compared with the theoretical predictions. Pile depth variations of 45 and 50 meters were performed in the plaxis analysis. In conclusion, the results of the two approaches will be contrasted. In the GIS 150 KV Tambak Lorok III Semarang project, soldier piles with a diameter of about 600 mm were driven 45 meters deep into the ground with hydraulic jacks. The theory led to the conclusion that the heave values for the effect of piling at -45 m depth and at -50 m depth were 0.1285 m and 0.1284 m, respectively. Based on Plaxis pile measurements at a depth of 45 meters, the vertical soil movement value was 5.80 cm, while 4.90 cm was recorded for a depth of 50 meters.