Evaluation of soft ground treatment in outer circular highway, Sri Lanka | |
| Author | Madushani Rajamanthri, Rajamanthri A.K. |
| Call Number | AIT Caps. Proj. no.CIE-18-37 |
| Subject(s) | Soil stabilization--Sri Lanka Soil mechanics--Sri Lanka |
| Note | A capstone project report submitted in partial fulfillment of the requirements for the degree of Bachelor of Science in Engineering Civil and Infrastructure Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Caps. Proj. ; no. CIE-18-37 |
| Abstract | This paper presents the results of comparison of settlements between actual field settlements and estimated settlements for Outer Circular Highway in Sri Lanka. The OCH was con- structed approximately from 2012 January to 2015 September. Generally, this highway con- sisted of soft clay, sand or clay particles with plant residues. The gravel compaction piles were installed with a spacing of 1.0 m to 1.3 m and having a diameter of 0.5 m to 0.8 m depending on the thickness of soft layer. Monitoring instruments including settlement plates and piezometers were installed and monitored during construction of highway. Use of gravel compaction pile is a ground improvement technique that can be applied when high embankments are be done on thick layers of soft soils. In such cases simplified methods like preloading may not be sufficient to provide required reinforcement. Gravel compaction piles installed in an appropriate grid pattern to reinforce the soft soil enhancing the shear strength and reducing the settlements. Since the gravel compaction piles material has higher strength than soft soil, it takes high amount of applied load from the embankment. This scenario is known as stress concentration of stone columns and hence reduces the settlements in a considerable amount. Not only increasing shear strength and reducing the settlements, stone columns also provide composite behaviour and reduce the possibility of failure, reduce the liquefaction potential etc. There are various methods are available for the analysis and design of gravel compaction piles. Under the various methods, mainly finite element analysis was used for acquiring the settlements after two years using PLAXIS software. In this paper field measured settlements were compared to estimate settlements to validate the soil properties, estimate long term prediction and find out most sensitive parameter in settlement variance. The results of this study showed that theres a high difference in settlement variance as a percentage and this structure is safe for its life time. Subsequently this paper presents that the most sensitive parameter for settlement variance is Over Consolidation Ratio. |
| Year | 2018 |
| Corresponding Series Added Entry | Asian Institute of Technology. Caps. Proj. ; no. CIE-18-37 |
| Type | Capstone Project |
| School | School of Engineering and Technology (SET) |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Civil and Infrastructure Engineering (CIE) |
| Chairperson(s) | Chao, Kuo-Chieh ;Tian Ho Seah (Co-Chairperson); |
| Degree | Capstone Project (B.Sc.)-Asian Institute of Technology, 2018 |