2017 PIE viaduct collapse: Contractor and 5 others charged; LTA to demolish unsafe sections

SINGAPORE — The main contractor and five people involved in last year's fatal collapse of an uncompleted Pan-Island Expressway (PIE) viaduct at Upper Changi Road East have been charged in court, three months after partial works resumed on the project.

The Land Transport Authority (LTA) said separately on Wednesday (May 30) that it had decided to demolish all the crossheads on the uncompleted sections of the viaduct as a safety precaution, and would similarly demolish any other sections found to be unsafe by an independent professional engineer.

This will only be done after the necessary approvals to proceed with the works have been obtained from the relevant authorities. "LTA is studying its options carefully and reviewing the viaduct project with OKP," an LTA spokesperson added in reference to Or Kim Peow (OKP) Contractors, the main contractor for the viaduct.

The LTA did not elaborate on the potential impact on the completion date of the viaduct, which will link the Tampines Expressway to the PIE and Upper Changi Road East by the first quarter of 2020. The stop work order on the site, which was issued after the incident on July 14 last year, was partially lifted in February.

OKP and its executive director Or Toh Wat, 50, were charged on Wednesday with failing to take necessary measures to ensure their employees' safety and health.

They were also charged with carrying out unauthorised strengthening works to sections of the viaduct without the approval of the Commissioner of Building Control, as well as failing to notify the Commissioner of Building Control of said strengthening works.

On the day of the incident, the contractor was carrying out works to cast the decking for the viaduct when a section of the structure collapsed while 11 workers were on it. Chinese national Chen Yinchuan, 31, died while the other workers suffered injuries.

Cracks were subsequently discovered at several locations at the corbel area on the remaining viaduct. Preliminary findings revealed that the corbels — stone support structures — broke under the weight of wet concrete.

After the accident, propping was extended to the parts of the viaduct where cracks were discovered to ensure no safety risks, said the LTA.

A photo illustration showing the position of a crosshead relative to a corbel and a column. Photo: Ministry of Manpower

Court documents revealed that the company allegedly did not conduct an adequate risk assessment on the corbels, despite knowing there were cracks on them, and failed to stop the works.

OKP's project director Yee Chee Keong, 48, was slapped with three charges under the Workplace Safety and Health (WSH) Act, Building Control Act and the Penal Code. He allegedly failed to call for works to be stopped when he discovered cracks on the corbels that were supporting the deck slab the workers were on, and permitted the carrying out of the unauthorised strengthening works.

Yee, who was the technical controller of the viaduct's worksite, was also said to have deleted a WhatsApp conversation between OKP project engineer Wong Kiew Hai and himself, which allegedly contained photographs and information potentially relevant to criminal investigations.

Wong, 30, faced two charges similar to Yee's. He was charged with failing to call for works to be stopped when the cracks were discovered, as well as deleting the said WhatsApp conversation.

Meanwhile, CPG Consultants' professional engineer Robert Arianto Tjandra, who approved the design and supervision of the construction works, was charged with five counts under the WSH Act and Building Control Act.

The 44-year-old, who was the project's qualified person, purportedly put up structural plans without checking on the design assumptions made for the corbels. He also allegedly did not carry out the necessary remedial works to rectify the corbel designs even though he knew they could not support the deck slab.

He was further accused of falsely certifying that the structural plans and design calculations were prepared in accordance with the Building Control Act, failing to ensure the building works related to the permanent corbels structure were designed in accordance with the Act, failing to inform the Commissioner of Building Control and authorising the strengthening works without the Commissioner's approval.

The fifth person to be charged in connection with the case, Calibre Consulting Singapore executive Leong Sow Hon, 60, was hit with two charges under the Building Control Act. Calibre Consulting Singapore was the project's independent accredited checker tasked with double-checking Tjandra's load calculations.

Leong allegedly failed to evaluate, analyse and review the structural design, and perform original calculations for the permanent corbels. He was also said to have falsely certified that he carried out an evaluation, analysis and review of the plans of the building works in accordance with regulations.

OKP Contractors and the five accused would appear in court again on July 11. Tjandra was offered bail of S$15,000, while Yee and Wong were each offered bail of S$20,000.

OKP Contractors had won the contract bid for the viaduct project because it offered the lowest tender price, and had a "good track record" in completing many similar infrastructure projects, said Senior Minister of State Lam Pin Min in Parliament last August.

However, it had the lowest quality score, and was in fact given a low safety-performance score. The company was previously blacklisted between January and April last year for accumulating 25 demerit points.

The Manpower Ministry had been conducting investigations into separate workplace safety lapses and the death of a worker in 2015, for which OKP Contractors was convicted and fined a few days before last year's incident. Because of that, the company faces an enhanced fine of up to S$1 million if convicted of failing to ensure their employees' safety and health.

Dr Lam told the House in August that investigations into the collapse would be wrapped up by October 2017.