Improving Engineering Properties of Soft Soil Using Preloading and Prefabricated Vertical Drains
نویسنده
چکیده
Preloading and Prefabricated Vertical Drains (PVD) is a ground improvement technique used to increase the consolidation process of clayey soils by means of shortening the drainage path. This paper discusses a case study of a road construction where a part of road alignment goes through a low laying water logged area. Primary consolidation of soft clay will continue for longer period of time after the road pavement is constructed which results in cracking and uneven settlement of the pavement to avoid such a problem ground improvement in the form of prefabricated vertical drains was recommended. Recent improvement in the finite element method analysis has enabled modeling of PVD in finite element software for calculating the settlement magnitude and time rate of consolidation. This paper gives the finite element modeling (FEM) of the proposed layer of road where ground improvement is done by prefabricated vertical drains. Field Settlement values of road at different time intervals are compared with the settlement magnitudes obtained from the FEM model. Field Settlement values with and without placement of vertical drains is also compared. The ultimate strength of soil was found to be increased due the preloading by the action of PVD.
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