A CASE STUDY ON CAUSATION OF THE LANDSLIDE IN PORONG-SIDOARJO FOR ROAD CONSTRUCTION WITH HIGH EMBANKMENTS ELEVATION

Abstract

Landslides occur in virtually every region of the world under diverse environmental conditions and topographies. These events negatively impact humans, resulting in countless casualties. Therefore, this research aims to determine the causes of landslides on man-made national road embankments in East Java, Indonesia. In addition, the occurrences at high elevations, despite reinforcement with soil retaining walls and group pile foundations, appear to be major sources of concern. In the present study, back analysis is conducted to evaluate the conditions of soil subgrade, existing pile capacity, and the effects of groundwater table on embankment stability, as slides typically occur after intense rainfall. Moreover, a stability analysis is carried out using the limit equilibrium process, and the embankment capacity assessment incorporates the anti-slide pile design method. The results show that the landslides are caused by varying soil depths. However, in a landslide embankment section, the soft soil depth appears deeper, compared to the middle zone, where soil data are employed in the existing reinforcement design. Furthermore, the overall stability evaluation for sliding requires wider application in anti-slide pile planning to complement the passive/active stress assessments on the retaining wall. Planning for anti-slide pile design is more often done using active and passive pressure calculations compared to overall stability calculations. Therefore, the results of this study can be used as suggestions for further planning, especially those related to overall stability.