LTA 1029/ 1030 Consultancy Works of Soil Investigation for MRT Cross Island Line in Singapore
Cross Island Line (CRL) is a planned Mass Rapid Transit (MRT) line in Singapore. The CRL will be about 50km in length and is targeted to complete around 2030. The CRL which starts from Changi, passing through Loyan, Pasir Ris, Hougan, Ang Mo Kio, Bukitima, Clementi, West Coast and Jurong, is expected to have a daily ridership of at least 600,000 commuters.
The Land Transport Authority (LTA) in Singapore has started Soil Investigation (SI) works to investigate and evaluate soil and rock conditions along the alignment of the CRL. The LTA has appointed SI companies to carry out the SI work which consist of a lot of boreholes (more than 1,000) including Drilling, Standard Penetration Test (SPT), Undisturbed Soil Sampling, Rock core sampling, geophysical survey, Soil and Rock laboratory tests, etc. These soil and rock information obtained will be utilized in the subsequent design and construction stages.
Kiso-Jiban Consultants Co., Ltd. (KJC) has been appointed as a geotechnical specialist for Consultancy works for C1029 and C1030 by the LTA to evaluate the SI companies’ investigation qualities. KJC’s major contributions to the projects are mentions as follows:
(1) During the field and laboratory works carried out by the SI companies, KJC has provided technical oversight on the field and laboratory works carried out. KJS’s site engineers have conducted technical audit check whether methods and procedures of the field and laboratory works have been carried out in accordance with the Standards, Codes, approved methodology and test procedures (refer to Fig1).
(2) KJC has conducted additional SI to counter-check and verify against the SI works carried out by the SI companies. The additional SI has involved not only the general SI works such as drilling, sampling and laboratory tests, but also the special SI works such as high quality undisturbed sampling (Gel-pushed Sampling, refer to Fig2), Seismic Cone Penetration Test, Bender Element Test, etc.
(3) KJC has prepared Geotechnical Interpretative Report (GIR) for the subsequent design and construction stages based on the factual reports prepared by the SI Contractor and the KJC’s additional SI report. Through vetting the factual reports prepared by the SI Contractors, discrepancies between the factual reports of both the SI companies and KJC have been reconciled as appropriate.