Upon completion of his doctorate research from National University of Singapore in 1992, he joined APG
Geo-systems Pte Ltd, an established local geotechnical specialist contractor as the Head of Design
Department until December 1996. In the following year, he set up Geostruct International Pte. Ltd. as a
specialist firm to provide engineering design, review and/or supervision of complicated geotechnical works.
Since then, Dr Yong had participated as a geotechnical specialist consultant in more than 150 projects of
varying scale over countries such as Singapore, Malaysia, Thailand, Vietnam, Indonesia, Pakistan, United
Arab Emigrates and PR China. These projects comprised deep foundation elements, basement excavation
works and under-ground structures including caverns and tunnels, particularly the Singapore MRT Circle Line
and Downtown Line Projects, sub-structure for high-rise towers, slopes, permanent and temporary earth
retaining walls, shallow and deep-seated chemical injections, land-filling, mega reclamation works, etc,.
Apart from engineering design and field supervision, he also involved in the failure investigation, remedial
proposal and expert witness in both Singapore and Malaysia.