Selasa, 3 Mac 2009

STRUCTURAL FAILURES DUE TO HUMAN ERRORS: THE COLLAPSE OF HIGHLAND TOWERS CONDOMINIUM AND THE CRACKS OF MIDDLE RING ROAD 2 (MRR2) IN MALAYSIA

MSC. BUILDING SERVICES ENGINEERING

ABSTRACT:

Structural failures occur from time to time, not only in Malaysia but also through world wide. However, the coming of sophisticated technology such as the application of software tools in structural system cause the nowadays engineering students and professional engineers unaware of the human factors that cause to the structural failures. Today, there are many articles, books and conferences have been discussed about the structural failures due to the human factors. In Malaysia many cases of the structural failures but the most famous are Highland Towers Condominium and Middle Ring Road 2 (MRR2) that was blown up by media with the concern of the public safety. This issue is something that should be interest to engineers as the word "structure" more synonym to engineers.

0.0 INTRODUCTION

It is indicated by Alexander and Abi, 2006 that structural failures occur from time to time, as seen from the recent (January 2006) rash of roof collapses in Germany, Poland, and Rusia. Even though, there are many investigations, examinations and prevention identified and approached but still have the issue on the structural failures. In Malaysia itself, there are many cases of structural failures whether they are due to human errors during design or construction stage, software tools, stochastic variability or uncertainty. Take for examples the cracks appear on a 20m high concrete retaining wall at Taman Meru Jaya in Ipoh, Perak (Mohd Nazam Md Kassim, 2008), the collapse of Bungalow at Taman Hillview, cracks of MRR2, the collapse of Highland Towers Condominium and many more.

There are many investigation have been carried out across the world in analyzing the event that cause the structural failures and revealed that a majority occurred as a result of human errors particularly those occurring during design and construction stage (Buletin Ingenieur, 1995, pp. 29). Thus, the study on the two cases; Highland Towers Condominium and MRR2 which are situated in Malaysia will come across on the possibility if human errors contribute to those problems. Besides, the study also will identify the effects of structural failures to the users and what are the initiatives has been taken in order to eliminate or reduce the occurrences of the human errors which due to structural failures.

1.0 DEFINITION

2.1 Structural failure

Based on the Buletin Ingenieur, 1995, 'structural failure' is defined as the incapacity of a structure or its components to perform as specified in the design and construction requirements (quoted in Hadipriono, 1985). Thus, the failure of the structural also can be referred to the word collapse, cracks, trembled down which is related to the part of the structure to fail in functioning.

By referring to Macmillan English Dictionary, 2002, 'structural' means related to the structure of something such as building and 'failure' means a sudden loss of a particular quality or ability, especially in a difficult situation. Therefore, structural failed to function also can be due to respective failure modes such as instability, fatigue, or any which cause to the inservicibility of the structure or its components which is not resulted to collapse, or trembled down but it only can cause to cracks, shrinkage or settlement.

2.2 Human Errors

Oxford Dictionary and Thesaurus, 2007, the word 'human' referring to human being, a man, woman or child and similar meaning to the word weak, vulnerable, erring and imperfect whereas the word 'error' means a mistake, or being wrong and similar meaning with the word inaccuracy, miscalculation, blunder, slip-up, oversight, misprint, fallacy or misconception. Based on the definition clearly shows that human are highly in tendency to make error or doing wrong in whatever they do. Thus, there is possible that the structural failures due to the human errors whether during design stage or construction stage.

2.0 METHODOLOGY

The methodology is the framework of the whole term paper presented. This is how the researcher derived his information in organizing way. In this term paper, the researcher used the collection of data from primary data and secondary data. The methodology applied in this paper is simplified in the Figure 3.1 below which is abstracted from Haslina Abd. Hamid, 2006. According to Naoum, 2003, there are many ways in getting and gathering information, by primary data (survey, case studies, and interview) and secondary data (books, journals, magazines. etc.)

However, this term paper focused on the secondary data which is data from books, journals, articles, newspaper and then goes through the case study of the two cases that has been chosen.

Figure 3.1: Research Methodology Structures

3.0 DATA ANALYSIS AND FINDINGS

3.1 CASE STUDY 1 – THE COLLAPSE OF HIGHLAND TOWER CONDOMINIUM

Highland Towers Condominium situated in Taman Hillview, Ulu Klang, Selangor, Malaysia. It was constructed sometime between 1975 and 1978. The Highland Towers were three blocks of 12-storey apartment; each block was respectively named Block 1, Block 2 and Block 3.

A Block of Highland Towers Condominium collapse in December 1993 not only causes to the loss of property but also sacrifice 48 lives as per photo 4.1.1.

Photo 4.1.1 Block 1 of Highland Towers at Taman Hillview Selangor, Malaysia collapsed on

11th December 1993 (*abstracted from gnp-geo@gnpgroup.com.my)

3.1.1 FINDINGS

Based on Majlis Perbandaran Ampang Jaya, 1994, the collapsed of Highland Towers Condominium was due to landslide that has been triggered by the structural failure of a rubble wall there. It has been reported that the Factor of Safety of the rubble wall in the Highland Towers was found to be less than 1.0 even without considering any presence of geological features such as relic joints and water table. Here, obviously, the human error in preparing inadequate design of walls and slopes during the design stage caused to the structural failure of the rubble wall which also contribute to the structural failure of a block of Highland Towers Condominium.

As according to gnp-geo@gnpgroup.com.my, a team of expert from different field has carried out a detailed investigation into the causes of the Highland Towers collapse and the result is the site is found to be tectonically stable and no active fault movements had been recorded.

Buletin Ingenieur, 1995, also reported that geotechnical in nature, involving weak foundations and succession of landslide due to the collapse of the building structure.

Based on Trett Consulting, the landslide that brought down Block 1 of Highland Towers was found by the Court to have been a rotational retrogressive slide emanating from a high retaining wall behind the second of a third-tier car park serving the 3 blocks of the Highland Towers. This failure due to high wall to fail because of water emanated from poor and non-maintained drainage, as well as a leaking pipe culvert carrying the waters of the diverted East Stream. In accordance with the judgments by the consulting resulted to the followings report:

The First Defendant was liable in negligence for:

i. not engaging a qualified architect,

ii. constructing insufficient and inadequate terraces, retaining walls and drains on the hill slope which could reasonably have been foreseen to have caused the collapse

iii. Diverting the East Stream from its natural course and failing to ensure the pipe culvert diversion was adequate, and in nuisance for not maintaining drains and retaining walls.

The Second Defendant (Architect) was liable in negligence for:

i. not having ensured adequate drainage and retaining walls were built on the hill slope adjacent to the Highland Towers site, which he foresaw or ought to have foreseen would pose a danger to the buildings he was in charge of,

ii. not complying with the requirements of the authorities in respect of drainage, in colluding with the First Defendant and Third Defendant (the Engineer) to obtain a Certificate of Fitness without fulfilling the conditions imposed by the Fourth Defendant (the Local Authority), in so doing not complying with his duties as Architect, and

iii. not investigating the terracing of the hill slopes and construction of retaining walls even though he was aware they would affect the buildings he was in charge of, and also in nuisance as he was an unreasonable user of land.

The Third Defendant (Engineer) was liable in negligence for

i. not having taken into account the hill or slope behind the Towers,

ii. not having designed and constructed a foundation to accommodate the lateral loads of a landslide or alternatively to have ensured that the adjacent hill slope was stable,

iii. not having implemented that approved drainage scheme,

iv. Colluding with the First and Second Defendants to obtain a Certificate of Fitness without fulfilling the conditions imposed by the Fourth Defendant and also in nuisance as he was an unreasonable user of land.

In relation to that it caused to the loss of property and sacrificed life. Thus, Buletin Ingenieur, 1995 stated that the Ministry of Housing and Local Government take serious consideration by:

· Established Construction industry Development Board (CIDB) to control the quality of construction works

· Amend the Roads, Drainage and Building Act 1974 that enable the local authorities to terminate of project if project to be found unsafe and fund amounting RM 50,000 to RM 500,000 or 10 years imprisonment to the responsible person.

· Imposing more strict conditions for the construction of high rise buildings particularly on hill slopes and mining land, the foundations of which must be approved by a registered geotechnical engineer.

· The requirement imposes for the local authorities to check the safety of buildings of more than five storeys high for every 10 years.

· Increasing awareness among developers, engineers and contractors that they are equally liable for any failures that may happen and that they may be charged under a criminal procedure so that, they are required to submit their names to the relevant authorities prior to construction.

· Employment of only qualified and suitable professionals for checking and approval of plan. For this purpose, all town and district councils should include at least one experienced engineer in their organization.

Besides, based on Faisal and Hui, 2006 pp. 146-153, due to many disaster due to landslide or soil erosion so there are the suggestion on the implementation of EWARNS (Early Warning And Risk Navigation System) to local authorities. Through EWARNS, can provide timely warning to the public and authorities via SMS alerts, especially concerned and affected parties to take specific precaution wherever any warning of high risks areas is triggered.

3.2 CASE STUDY 2 – THE CRACKS OF MIDDLE RING ROAD 2 (MRR2)

Middle Ring Road 2 or well-known as MRR2 is constructed by package. The crack occurred is at flyover in Package 11 with cost RM 238 million. The discovery of the crack is 1.7km section of MRR2 from Kepong Indah to the Damansara-Puchong Highway since 9th August 2004. Besides, there are also problem occurred when concrete fibre fell from pillar 28 after repairing works has been done cost RM 75 million. Photo 4.2.1 is the pillar 28.

Photo 4.2.1 Protective covering on Pillar 28 of MRR2 bridge in Kepong (abstracted from nstonline, 2008)

The Particular detail of construction team involved is:

Halcrow Consultancy Ltd, a British consultant

Leonhardt and Andra, a German consultant

Contractor, Sukmin-Bumihiway-KKM(Wilayah)

3.2.1 FINDINGS

According to Wahid 2006, the crack formation of MRR2 may be due to design and construction errors. However, the exact official report of the possible causes of the crack is not publishing to public but it should be available access for desk study as to increase the awareness of engineers due to the mistake.

As stated in New Straits Times, 2004, there are also spark off by reporter that the crack due to the design of the crossbeam of flyover, and the length of column reinforcement. Clearly, there were design deficiencies and problems in detailing.

According to The Sun, 2008, the problem of pillar 28 , where three pieces of carbon fibre reinforced plastic (CFRP) was crack and snap. As said by Parliament's Public Accounts Committee (PAC) chairman Datuk Seri Azmi Khalid, Public Works Department (PWD) is still investigating if the crack is because of the material failure. Roger Buckby, Halcrow's senior consultant said that, the company advised the PWD in 2005 not to use such carbon fibre straps because of the problem of ductility but the department still proceeded with such material.

Based on the new Work Minister, Datuk Mohd Zin Mohd said that tensile stress on the highway might have been too much for the CFRP to bear which cause the carbon to snap and crack.

Due to crack of MRR2 and the failure of pillar to support the flyover, so PWD take initiative to close two lanes and only one lane open to users. According to Star Online, 2008, the jam stretched over 3km to the Bandar Sri Damansara toll plaza after the three-lane road was reduced to one. This also caused the users to stark in the jam almost 2 hours before the lanes we re-opened.

Therefore, the initiative taken for safety purpose is to close the MRR2 that affected by the faulty pillar and beam crack and a crane is used to peel away the remaining dangling pieces of concrete and conduct inspection works.

The defect works taken is that the faulty pillar is wrapped to prevent more pieces of carbon fibre from falling. The PWD will affix a temporary support brace called 'tie-frame', the metal structure on the affect pillar 28 of MRR2. Besides, Datuk Seri Azmi Khalid also mentioned that, PAC proposing for stringent standard operating procedures (SOP) in terms of structure inspection on JKR. This is in addition to having more regular inspection to the current twice per annum practice. He mentioned also that PAC should have a special meeting after receiving the preliminary investigation report from JKR.

PWD also has taken the contractor, Bumi-Hiway to court due to the incident.

5.0 DISCUSSION

Based on the findings above, therefore it can be summarized on the factors due to structural failures, the effects towards users and the prevent action taken in order to reduce the structural failures from occurring again.

5.1.1 THE HUMAN FACTORS CONTRIBUTE TO STRUCTURAL FAILURES

Based on the thorough study on the two cases above, the types of human errors that contribute to the structural failures are:-

· Preparing inadequate design of structural components during the design stage

· Not compliance with the standards code of practice in determining the safety factor

· Geotechnical engineer not properly carried out the soil investigation which result to weak foundation

· Preparing inadequate design of drainage caused the water not properly discharge

· Failure in determining the suitable material to be used

· Inaccurate result of structural design analysis

· Selfishness and unaware of the responsibilities (Professional ethics)

5.1.2 THE EFFECTS OF STRUCTURAL FAILURES TO USERS

  • Caused the users starked in jammed everyday until re-opened of the MRR2.
  • Create higher risk for accident to occur
  • Users suffer due to the unavailability of public facilities that they are deserved
  • Make unsmooth traffic flow that affect in terms of time and cost of users

5.1.3 THE ACTION TAKEN TO REDUCE THE STRUCTURAL FAILURES CASES

  • Establish a body to monitor and control the construction project such as CIDB.
  • Increase fund and responsibility as to increase awareness to construction team
  • Empower stringent approval procedure as to enhance the awareness of particular involved in construction world

6.0 CONCLUSION

As a conclusion, the collapse of Highland Towers Condominium and the crack of MRR2 are due to human errors during design and construction stage. Although today there are the coming of sophisticated technologies which can carry human works with minimum inaccuracy but yet still the human errors occur. Therefore, the structural failures act as alarm trigger to the professionals to aware on their possibilities on performing their task. This is as lesson as the phrase 'learn from mistakes'. In addition to that, initiatives have been taken due to the failures as to enhance the performance and knowledge of the construction team.