Press Releases
Sep-icon
24 September 2018
Ground/Structures Settlement Issues Related to Construction Works

(24 September 2018, Hong Kong) In response to the recent public concerns on ground and structures settlements, The Hong Kong Institution of Engineers (HKIE) expresses its professional views on the issue as follows: -

 

Causes of Ground Settlement

 

With ever-growing population, the need for housing and accommodation as well as infrastructure facilities continues to grow which demands more developments and construction works in Hong Kong. These construction activities will inevitably induce soil or underground disturbance to the adjacent ground and buildings in particular for sites underlain by soft marine deposits and weak fill layers.

 

Pile and raft foundation construction are conventional systems to support building structures. Excavation and lateral support works (ELS works) is normally called for in the construction of pile caps, basement, underground drainage and tunnel works.

 

In response to various ground and site conditions, professional civil/structural/geotechnical engineers will develop a most suitable foundation and works to limit the induced settlement and possible disturbance to the adjacent ground/structures so as to ensure public safety.

 

Statutory Control

 

The Buildings Department (BD) has established a stringent controlling system under the Buildings Ordinance for foundation and basement works to ensure safety of the buildings/structures and the public.

 

A series of Practice Note and Code of Practice stipulate the settlement limits for piling and excavation works have been promulgated to the registered professionals (i.e. Authorised Person/Registered Structural Engineer/Registered Geotechnical Engineer under the Buildings Ordinance) and the building industry for reference and to follow.

 

Prior to commencement of site works, a comprehensive instrumentation and monitoring plan with a set of Alert, Alarm and Action (AAA) values shall be proposed by the project registered professionals to form a mechanism for controlling site activities with regular review of the site situations.

 

For general case with no sensitive adjacent buildings, structures and services, the ground settlement limit of 25mm will be adopted as generic figure for the Action level.


The project registered professionals will submit an investigation report regarding the excessive settlement issue together with technical justifications for higher ground settlement limits with respect to the insitu ground conditions, existing structural forms and conditions of adjacent buildings, existing utilities and services for subsequent construction works for BD’s approval.

 

For developments within the Railway Protection areas, the practice note issued by BD has stipulated certain settlement and movement limitations. However, these figures are only generic values and do not imply the railway related structures will be adversely affected.

In case the settlement is to be exceeded or has been exceeded, the registered professionals shall submit an investigation report and design checking for the existing MTR structures to support their request for relaxation of settlement limits. BD and MTRCL-Railway Protection Section will review the submission for approval if structural, railway and public safety can be justified.

 

Engineer’s Assessment of Ground Settlement Limit

 

The ground settlement limit of 25mm as described above is of general case. Different structures and services will have different tolerance level in accommodating movements.

 

For the case where there is nearby listed heritage or pre-war buildings, the tolerable ground settlement limited shall become more stringent to much less than 25mm, or even as low as 5mm. There is no single figure on tolerable ground and buildings settlement for all types of design and construction. The acceptable ground and structure settlement limits should be assessed on case by case basis according to different project requirements, site and existing structures’ conditions.

 

Similar assessment shall also be conducted by the registered professionals to protect the utilities around construction site from damages.

 

Conclusion

 

In conclusion, construction works will inevitably induce certain amount of soil or underground disturbance. While there is a set of general guidelines for the consideration of Engineers on the tolerable ground settlement in their design, Government Authorities have set up stringent controlling mechanism to ensure building and public safety would not be compromised by any developments and/or construction works.

 

Tolerable ground and building settlement limit is not any single figure which can be universally applicable to all design and construction, but shall vary case by case and should be reviewed and agreed by the Government Authorities (and/or the MTRCL – Rail Protection Section) upon to meet specific criteria of individual projects and works.

 

The HKIE has jointly organised with the Faculty of Engineering of The University of Hong Kong a public seminar titled “The Mystery of Ground Settlement” at 6:00 – 7:00 pm at the Lecture Theatre A, Chow Yei Ching Building, The University of Hong Kong on 26 September 2018.

 

We hope this seminar can further explain the meaning and essence of ground settlement to the general public.


Attachment:

Poster of “The Mystery of Ground Settlement” / 公開講座:「沉降之謎」海報

 

View video:

公開講座:「沉降之謎」
Video from Department of Civil Engineering, The University of Hong Kong
All information and views expressed by speakers and in their presentation materials do not reflect the official opinion and position of the HKIE. No responsibility is accepted by the HKIE for such information and views including their accuracy, correctness and veracity.

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Sep-icon
14 September 2018
日本關西機場沉降問題之回應

(香港,二零一八年九月十三日) 香港工程師學會(下稱「學會」)留意到在強颱風「飛燕」導致日本關西機場兩條跑道嚴重水浸後,社會關注赤鱲角香港國際機場的沉降及於惡劣天氣後水浸的可能性。

 

關西機場由兩個人工島組成,總面積約1,050公頃,於水深大概18至20米的海域建造,海床下面有數十層不同地質年齡的海洋黏土和沙土,總厚度近400米。這些由海洋環境沉澱而成的海洋土層,土質硬度比較低,若受壓力會被壓縮導致沉降。加上由於大阪灣水深達18-20米,需要大量填土來製造人工島,人工島總共耗用4億3千萬立方米的填土,龐大重量令海洋土層承受巨大的壓力,令土層受到壓力之下壓縮而導致沉降。第一個人工島上的跑道於1994年啟用,第二個人工島上的跑道於2007年啟用。有學術文獻指出,直至2012年底,第一個人工島和第二個人工島分別累積沉降超過12米及14米。由此可見,關西機場嚴重的沉降問題是由於填土壓力以及非常獨特的地質環境所造成的。

 

同樣由填海造成的赤鱲角香港國際機場,採用傳統稱之為「浚挖式填海」方法,填海範圍約 938公頃,海水深度大約為5米。雖然海床表面同樣有土質比較軟的海洋淤泥,但在正式填海前,這些淤泥已被挖走以減低長遠沉降的程度。這些淤泥底部是一層10至30米相對較堅固的沖積土層;冲積土層以下是堅硬的花崗岩及其風化物,根據這些地質條件及填海方法,香港國際機場人工島的沉降幅度會遠遠低於關西機場,類似的沉降情況亦不會出現,或對機場正常運作構成任何影響。事實上,香港百多年來通過填海工程增加土地供應,多項大型工程如啟德機場和葵涌貨櫃碼頭等亦建基於填海範圍,歷經不少惡劣天氣情況,亦未有出現類似關西機場的沉降情況。

 

至於正在興建的第三條跑道,因為環境保護理由採用了「非浚挖式填海」方法,此方法能避免浚挖及傾倒淤泥、減少使用回填物料及沉積物懸浮量,從而減低對環境及水質的影響,維護海洋生態。為了減少因不挖走淤泥而可能導致的沉降,工程採用一種名為「深層水泥拌合法」的技術,於填海之前,大量水泥會被拌合入淤泥層之中,令加固後的淤泥能夠有足夠的承載力,有效減少填海期間沉降及長遠出現的剩餘沉降。

 

赤鱲角香港國際機場與關西機場無論在海洋與地質環境,以及填海方法兩方面都有相異之處,因此兩地的沉降情況截然不同。

 

學會一直致力推動工程專業,以專業知識及技術建設香港,與市民共創未來。

 

如欲垂詢,請與香港工程師學會傳訊統籌部聯絡。

 

電話:2895 4446

傳真:2882 6825

電郵:corpcom@hkie.org.hk

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Sep-icon
04 September 2018
香港工程師學會 土地供應策略意見書 The Hong Kong Institution of Engineers Views on Land Supply Strategy

(香港,二零一八年九月四日) 香港工程師學會 (下稱「學會」) 就土地供應策略向土地供應專責小組及立法會發展事務委員會提交意見書。

 

學會一直倡議提升市民生活質素及可持續發展,我們支持以多管齊下的方式增加土地供應。

 

學會支持填海,並認為填海能增加大片土地。相比其他土地供應方案,填海對現行土地用途影響較少。我們認為現代工程技術可以減少填海工程對環境的負面影響。學會支持政府對具備潛力的近岸填海地點進行規劃和工程研究,並探索其他可能的填海地點。學會認同在大嶼山與香港島之間興建中部水域人工島,深具發展成為東大嶼都會的潛力,這對香港未來的發展和長遠策略性增長至關重要。

 

學會亦支持發展岩洞及地下空間以釋出市區土地。有見政府已完成「岩洞發展長遠策略–可行性研究」,學會建議有關部門盡快制訂計劃及把研究成果付諸實行。

 

就短中期而言,學會支持發展棕地及加強活化舊區。在推展市區重建之餘,學會期望社區的獨特性和特色能夠於重建計劃中得以保留。

學會支持政府增加額外土地儲備以應付未來各種發展需要,並制定藍圖和可實行的土地供應目標。

 

有關意見書已上載至香港工程師學會網站:http://hkie.org.hk/en/news/opinion/


如欲垂詢,請與香港工程師學會傳訊統籌部聯絡。

電話:2895 4446
傳真:2882 6825
電郵:corpcom@hkie.org.hk

 


 

(4 September 2018, Hong Kong) The Hong Kong Institution of Engineers (HKIE) has submitted our views on land supply strategy to the Task Force on Land Supply and the Panel on Development of the Legislative Council.

 

The HKIE advocates for developing Hong Kong under the aims of enhancing the living quality and livelihood of the citizens as well as facilitating sustainable development. We stress our support for adopting a multi-pronged approach for land supply.

 

The HKIE supports reclamation and considers that reclamation is an efficient method to generate few large pieces of new land. Compared to other land supply options, reclamation can minimise the impacts on existing land use. We consider that modern engineering technologies could help minimise negative impacts from reclamation to the environment.

 

The HKIE supports the Administration to proceed in carrying out detailed planning and engineering studies for reclamation on identified suitable sites and exploring other potential reclamation sites. In particular, the HKIE agrees the development potential for artificial islands in the Central Waters between Lantau and Hong Kong Island for developing the East Lantau Metropolis is crucial for Hong Kong’s future development and long-term strategic growth.

 

The HKIE also considers that developing rock caverns and underground space development can create/ release land in the developed areas. Noting that the Administration has completed the “Long-term Strategy for Cavern Development – Feasibility Study”, the Institution suggests the Administration to formulate action plans and put the study findings into implementation in a timely manner.

 

In short-to-medium term, the Institution supports developing existing under-utilised brownfield sites and stepping up effective measures to rejuvenate the old districts. Along the urban renewal initiatives, the HKIE considers that the uniqueness and characteristics of the urban districts should be preserved.

 

The HKIE supports the Administration to pursue extra land reserves to meet various demands in future, as well as to develop a visionary blueprint and an attainable target for land supply.


The Submission is available on the HKIE website at:
http://hkie.org.hk/en/news/opinion/


For media enquiries, please contact:

 

The Hong Kong Institution of Engineers
Corporate Communications Section

 

Tel: 2895 4446
Fax: 2882 6825
Email: corpcom@hkie.org.hk

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Aug-icon
30 August 2018
香港工程師學會會長替任事宜 Presidency of The Hong Kong Institution of Engineers

(香港,二零一八年八月三十日) 香港工程師學會 (下稱「學會」) 宣布,學會理事會昨日 (八月二十九日) 已決定接受學會會長黃唯銘博士、工程師的辭職,並通過高級副會長余錫萬工程師為新任會長。

黃唯銘博士、工程師離任後即時由余錫萬工程師接任,並將於二零一八年九月一日生效。

學會理事會藉此衷心感謝所有媒體朋友在此期間對學會的關心。

 

如欲垂詢,請與香港工程師學會傳訊統籌部聯絡。

 

電話:2895 4446 / 6398 4599
傳真:2882 6825
電郵:corpcom@hkie.org.hk


附件:
1. 余錫萬工程師的簡歷

 


 

(30 August 2018, Hong Kong) The Hong Kong Institution of Engineers is pleased to announce on 29 August 2018 the Council of the Institution had unanimously resolved to accept the resignation from President Ir Dr Philco N K Wong from the office of the President for this Session and that the Senior Vice President Ir Ringo S M Yu as the new President.

Ir Dr Philco N K Wong will vacate his office and Ir Ringo S M Yu is to be installed as the new President both taking effect on 1 September 2018.

The Council of the Institution wishes to convey their heartfelt gratitude to all the media friends for their caring concerns of the Institution during this period.


For media enquiries, please contact:

 

The Hong Kong Institution of Engineers
Corporate Communications Section

 

Tel: 2895 4446 / 6398 4599
Fax: 2882 6825
Email: corpcom@hkie.org.hk


Attachment:
1. Biography of Ir Ringo S M YU

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Aug-icon
08 August 2018
香港工程師學會回應沙中綫事件

(香港,二零一八年八月八日) 香港工程師學會(下稱「學會」)關注到沙中綫項目事件持續帶給整個社會、港鐵公司及整體工程界的衝擊。學會歡迎政府決定採取迅速而果斷的行動。

學會不會就政府當局在新聞稿中所引述發現的屋宇圖則差異發表評論,但從表面上相信證據必須非常充分和有力,而且應該是有足夠理由要求港鐵公司立即改變高級管理層,並向執法部門再次報案作出調查。因此,學會期望當局作出迅速調查及處理這事件,以恢復市民對相關工程及工程界從業人員的信心。

對於像沙中綫這樣規模龐大的工程項目,需要六百至七百名監督人員去監管大約五千到六千名從業人員,其複雜性不難理解。在這方面,學會深信港鐵公司應會提供足夠的法律支援,並讓三名已離職的工程總經理去獲得所需資料,以保障他們的權利去澄清事件,即使他們已離開了港鐵公司。畢竟,任何事故都是發生在他們在職工作期間,亦應涵蓋於相關港鐵工程項目誠投的專業保險。

學會重申對若被裁定犯有不誠實或欺詐行為的會員,不論其資歷,學會不會容忍及定會採取適當與相應的紀律行動及處分,這包括將他們驅逐出學會。

 

學會上任會長陳國璋工程師
高級副會長余錫萬工程師
副會長源栢樑博士、工程師
副會長鍾國輝工程師

 


香港工程師學會回應沙中綫事件(補充)


(香港,二零一八年八月八日) 香港工程師學會(下稱「學會」)收到不少媒體查詢為何黃會長並沒有署名於今早的聲明,因此懷疑黃會長已辭任會長一職。事實上我們收到黃會長指示,他不會就相關沙中綫工程發表任何意見或評論。另外黃會長亦已致函所有學會會員,在他向港鐵辭職後將會全身投入會務事宜。

如因此有任何混亂引起,我們表示歉意。

學會上任會長陳國璋工程師
高級副會長余錫萬工程師
副會長源栢樑博士、工程師
副會長鍾國輝工程師

 


The HKIE’s Response to the Shatin to Central Link Incident


(8 August 2018, Hong Kong) The Hong Kong Institution of Engineers (HKIE) is disturbed of the turmoil caused by the Shatin to Central Link (SCL) incident that has brought to the public, the MTR Corporation Limited (MTRCL), and the engineering profession as a whole. The HKIE concurs with the government in taking immediate and decisive actions to settle this issue.

 

The HKIE is not in a position to comment over the discrepancies in relevant drawings as alleged. It appears though, they must be of some sufficient and strong evidence, and with firm grounds for the government to demand the MTRCL redressing the senior management, and again reporting the incident to the law enforcement agency for further investigation. As such, the Institution opines the facts of this matter could be elucidated soon enough in restoring the public confidence in the relevant SCL project and the engineering profession.

 

A complex project as SCL, would require some 600 to 700 supervisory staff to supervise 5,000 to 6,000 working staff. The HKIE believes that the MTRCL will provide relevant legal assistance to the three concerned general managers who have left their posts, and allow their acquisition of necessary information to protect their rights in making clarification of the incident, considering that the matters of the incident occurred during their tenure of employment, which should also be covered under the professional insurance purchased for the MTRCL project.

 

The HKIE will reiterate that should any member be found guilty of dishonesty or fraud, the Institution would not accept such conduct and would take appropriate disciplinary actions, including expulsion from the Institution, regardless of the qualifications of the member.

 

Immediate Past President Ir Thomas K C CHAN
Senior Vice President Ir Ringo S M YU
Vice President Ir Dr YUEN Pak Leung
Vice President Ir Edwin K F CHUNG

 

[On his instruction, President Ir Dr Philco Wong would refrain from any involvement on this matter]

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