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Japanese Infrastructure Newsletter

I n f r a s t r u c t u r e D e v e l o p m e n t I n s t i t u t e — J A P A N

January 2008 No.42

“Harmonica” Tunneling Method 1

The MSW Landfill System with The Leakage Detection and Automatic Restoration 3

Transfer of Technology of River Purification for Overseas 6

C O N T E N T S

“Harmonica” Tunneling Method

Infrastructure Development Institute – Japan (IDI) New Kojimachi Bldg, 5-3-23, Kojimachi, Chiyoda-ku, Tokyo, 102-0083, JAPAN

Telephone: +81-3-3263-7901 Facsimile: +81-3-3230-4030 E-Mail: [email protected] Homepage: http://www.idi.or.jp/

IDI Europe Office Tour CIT, Bureau 605, 3, rue de I'Arrivée 75749 Paris Cedex 15, France

Telephone: +33-1-43 20 19 88 Facsimile: +33-1-43 20 97 16 E-Mail: [email protected]

IDI Beijing Office Room203, Tower1, Bright China Chang An Bldg, No7, Jianguomen Nei Av. Dong Cheng District Beijing, 100005, China

Telephone & Facsimile: +86-10-6517-1237

Infrastructure Development Institute - Japan

January 2008 No.42 1

Harmonica Tunneling Method

-Method of Constructing a Large Section Tunnel by Integrated Small Shield Tunnels- This technology won the excellence prize of the 9th Infrastructure Technology Development Award 2007 of the Japan Institute of Construction Engineering (JICE).

1. Harmonica Tunneling Method

The Harmonica Tunneling Method is a non-open-cut tunneling method for constructing large section tunnels or underpasses by integrating small section tunnels that are excavated with a rectangular shaped shield machine. This new tunneling method was named after the harmonica because the finished shape is similar to that of a harmonica (Fig.-1). A wagging cutter face type earth pressure balanced excavating machine is used for this method because it can excavate a rectangular cross section effectively (Fig.-2). A rectangular shaped steel segment is used for the tunnel lining of this method (Fig.-3). This tunneling method has recently been drawing attention as a quick and economical method for constructing tunnels and underpasses. We are already constructing using this method to construct three tunnels this year. Moreover, two more tunnels will be constructed in 2007. 2. Background

Recently, underpasses at intersections and railroad crossings have become necessary to reduce traffic congestion and the closure of the crossings during peak times. The open-cut tunneling method is normally used to construct underpasses. However, this method requires traffic enforcement, reduction of traffic lanes, and a long construction time. Therefore, a new method for building underpasses using a non-cut-and-cover method has become necessary. The preceding outer shell excavation methods such as the Prestressed Concrete Roof method (PCR method), an Under Railway/Road Tunneling method (URT method), and High Speed Element Pull & Jointed Element Structure method (HEP&JES Method) are well known in Japan as non-open-cut construction methods. However, these existing tunneling methods have various technical problems, such as the inability to excavate along curved alignments or long distances. The Harmonica tunneling method has been developed to solve these problems.

3. Effect of Technique

1) Because the Harmonica Tunneling Method uses a smaller machine than the large section shield tunneling method, it is possible to construct a shallow earth cover tunnel and underpass.

2) By using a small shield machine, it is possible to reduce the machinery and equipment required for excavating work and to decrease the area of the work zone on the road.

3) By using a shield machine, it is possible to excavate along vertically or horizontally curved alignments (Fig.-4). Moreover, the total construction cost is reduced because the departure and arrival shafts are smaller than those of existing methods.

4) By using this shield machine, it is possible to construct a long distance tunnel or underpass.

5) Although the preceding outer shell excavation methods require internal excavation of the area surrounded by the outer shell, the Harmonica tunneling method does not require such work.

6) Even though the Harmonica tunneling method uses steel segments, which serve as struts and supports, it does not require any special tunnel supports.

4. Work Procedure

1) Excavation Work First, the baseline tunnel is excavated, then the adjacent tunnel segment is also excavated along the baseline tunnel by using the same excavating machine (STEP1). After the completion of lower tunnel excavation, upper tunnel segments are excavated by the same procedure (STEP 2 to STEP 3).

2) Structural Work Before the re-bar fabrication work for the base slab is completed, obstacle steel plates and vertical ribs of each steel segment are removed (STEP 4). After the re-bar fabrication work is completed, the base concrete placement work is executed (STEP 5). Wall and roof slab construction is executed by the same procedures (STEP 6). After the concrete work is completed, the remaining



steel girders and skin plates in the new culvert are removed (STEP 7).

3) Finishing Work The interior and finishing work is executed (STEP 8).

5. Application

1) Underground Passageway Project in TOKYO (from Oct 01, 2004 to Sep 30, 2007)

Tunnel No.1 – 5,300×7,450mm L=40m Tunnel No.3 – 4,000×5,500mm L=30m 2) Railway Extension Project in Osaka (from June 19,

2003 to March 31, 2009) 7,350×9,800mm L=21.5m

6. Participants

Taisei Corporation, IHI Corporation, and Ishikawajima Construction Materials Co., Ltd.

Contact: Kazuo TAKAMIZAWA Taisei Corporation. Civil Engineering Division E-Mail: [email protected]

Figure-1 “Harmonica” Tunneling Method

Figure-2 Wagging Cutter Face Type EPB Machine

Figure-4 Completion of Excavation

(Vertically Curved Alignments) Figure-3 Steel Segment



The MSW Landfill System with the Leakage Detection and Automatic Restoration -An Impermeable Technology for MSW Landfill Sites to Protect the Environment-

This technology won the excellence prize of the 9th Infrastructure Technology Development Award 2007 of the Japan Institute of Construction Engineering (JICE).

1. The Background of This Technological

Development

There have been many attempts to solve the problems associated with disposing or recycling Municipal Solid Waste (MSW), however MSW continues to grow. Existing facilities will be full in a few years if new ones are not built. Finding new landfill sites has become harder and harder as residents’ concerns grow over possible contamination to ground water. To ease residents’ concerns, it has become necessary to develop a technology that will alleviate those concerns. 2. Contents of Technology

The MSW landfill system will require an impermeable liner sheet in order to prevent leakage. As the liner sheet could be punctured by sharp angled wastes, it has been decided that technology to detect such damage will be necessary. The goal of this technology is to convince residents that preventing and detecting leaks has been fully

safeguarded. The site is divided into some blocks by the pouched liner sheet (Fig.-6). Each block has a tube for detecting leakage. If the impermeable liner sheet is damaged, the leachate, assisted by gravity, will drain into the detection pit through a tube that is connection to the bag. If the lower impermeable liner sheet is punctured, a good inner permeable mat in the bag prevents leachate from leaking into the ground. If the sensor detects leakage, the data is transferred to the administration building where an LED in the control panel warns there is an emergency．Bentonite colloid solution is injected into the bag through the detecting /injecting tube．When the solution with water pressure comes out from the ventilator tube ， the injection is completed．The colloid solution restores the damage by making the mud cake in the bag (Fig.-7). The bag structure with the defect part is filled with bentonite colloid solution ． After restoring, it can continue to detect the leakage while monitoring the quantity of the solution decrease.

B1B2 B3 B1B2

B3

U1U2U3

Figure-5 Work Procedure



Figure-6 Outline of System

Figure-7 Restoring System with Bentonite Colloid



Figure-8 Comparison of Total Cost

3. Effect of Technique

As compared with former techniques, this technique can cut down 15% of total costs, (Fig.-8) and also enable the followings which contribute to safety of the neighboring environment.

① Continuous monitoring; It is possible not only to detect leaks from the damage, but also to monitor continuously for 24 hours.

② Easy repair; It is possible to repair the damage without digging through the waste.

③ Repeated repairs; If the same place is damaged again, it is possible to detect and repair.

④ Leachate status; It is possible to confirm the quantity and the quality of leachate by collecting it from the detecting tube.

⑤ Labor saving; It is possible to detect and repair from the computer requiring no special knowledge and no physical work.

4. Scope of Application

・ This technique is applicable any MSW landfill system.

・ It is desirable that the site is divided into area of about 200～500m2.

5. Application

・ Nagaizumi town MSW landfill (Photo-1) ・ Ohmata MSW landfill (Photo-2)

Contact: Siro SHIMONISHI Asanuma Corporation. Civil Engineering Division E-mail: [email protected] Fax: +81-3- 5269-3154

Photo-1 Nagaizumi Town MSW Landfill

Photo-2 Ohmata MSW Landfill

10,571 This technique

Former technique

Construction cost Material cost

（1,000yen） 0 5,000 10,000 15,000 20,000 25,000 30,000

8,184

2,864 6,547 15,345

21,142,000

24,756,000

About 15％ Reduction

（CASE：6820m2）

Monitoring cost

Monitoring cost Construction cost Material cost

2,387



Transfer of Technology of River Purification for Overseas

-For Promotion Diffusion of Gravel Contact Purification Technology in Taiwan-

Summary

At the end of 2006, the first river purification plant using the gravel contact oxidation method in Taiwan began operations and has continued working well up to the present date. In response to a request from Taiwan, the above project was planned, designed and built in collaboration between Japan and Taiwan as the first introduction abroad of river purification technology using gravel contract which originated in Japan. The favorable result of the project has led to a policy for widespread river-purification plants in Taiwan. Three are currently under construction now. 1. Introduction

IDI-Japan has been working to transfer Japanese construction technology overseas including river purification technology. NIHON SUIDO CONSULTANT Co., Ltd. (NSC) was commissioned for this project in Malaysia and conducted a field survey and designed and constructed an experimental facility in 2003. NSC also carried out monitoring surveys twice in summer and winter of 2004 to transfer the technology to the local engineers. From our experiences of the above surveys, this method could be adjusted to domestic features in design of the river purification and in considering specifications of facilities and maintenance method introduced as below.

2. Background of the Project

Taiwan authorities have been interested in Japanese river purification technology (especially the gravel contact oxidation process) as a measure against river pollution in Taiwan and collected information and toured the Tama River and Edo River purification facilities in Tokyo. The Taipei City Government threw a bidding on the Nanhu Purification Plant in November 2005 and JV including NSC, MWH-Taiwan and local contractor won this project through presentation of the proposal with NSC’s presence and instructions there. The facility was successfully completed in October 2006 and has been running smoothly ever since. Following the success of the Nanhu purification facility, three more similar facilities began construction from

the end of 2006 to 2007 and are now nearing completion. 3. About Nanhu Purification Plant

3.1 Outline of the Plant Nanhu purification plant was built to improve the water quality of the Keelung River which is polluted by wastewater. The following is the design specification for the Nanhu purification plant.

Table-1 Design Specification for

the Nanhu Purification Plant

Purification

method

Gravel contact oxidation method

with aeration

Volume of

purified water5,500 ㎥/d = 0.064 ㎥/s

Unpurified

water

Purified

water Water quality

condition

(mg/l)BOD

NH4-N

50

20

max. 10

max. 1.0

Capacity of

gravel tank

Necessary volume: 3,633 ㎥

(Detention time: 6hrs.)

Nitrification of high-level NH4-N determines the detention time and the oxygen volume necessary for the reaction (aeration) tank for purification. After consideration, detention time was specified to be 5 hours for nitrification. The volume of necessary oxygen was also set for full-nitrification of NH4-N.

3.2. Operational Aspect

The facility had a trial running for 8 months from October 2006 to May 2007 and produced the following results.

Figure-9 Bird’s-eye View of

the Nanhu Purification Site

Intake

Inflow distribution channel

Gravel contact purifier

Observation room

Discharge/sludge tank



Figure-10 Locations of 4 Purification Sites

Nanhu

Danshui Keelung

Dahan

Hsintein

Chengmei

Site C

Site S

・ Water volume load: approx. 100% except dry season (40-65%)

・ Inflow water quality: close to planned value (min. NH4-N=20mg/l)

・ Purified water quality (average): BOD/SS = 2 to 5mg/l, NH4-N=0.1mg/l

Purified water quality is quite good due to almost full-nitrification of NH4-N. The difference between the pollution degree of unpurified water and purified water was confirmed visually and received well by the people involved.

4. Outlines of Confirmed Purification Plants

Followed by the good operating condition of the Nanhu purification plant, three similar plants began construction. Table-2 outlines 2 projects and 4 purification plants including the Nanhu. Construction of the Chengmei and the S. purification plants are going to be completed within this fiscal year of 2008 and the C. purification plant will come to completion in the next fiscal year.

Operation of these four plants will help improve the water quality in the Keelung River and the Dansui River and is expected to improve the river environment together with other measures.

Keelung River purification project Hsintein Creek purification project

Name of purification

facility

Nanhu purification

facility

Chengmei purification

facility

S. purification

facility

C. purification

facility

Ordering party Taipei City Government Taipei Prefectural Government

Name of river Keelung River Hsintein Creek

Name of sewage

drainage channel

Nanhu pumping station

drainage channel

Chengmei pumping

station drainage

channel

S. pumping station

drainage channel

(3 channels)

C. pumping station

drainage channel

Purification water

volume 5,500 ㎥/d=0.064 ㎥/s 9,000 ㎥/d=0.104 ㎥/s 3,000 ㎥/d=0.035 ㎥/s 57,000m3/d=0.66 ㎥/s

Item Unpurified

water

Target

value

Unpurified

water

Target

value

Unpurified

water

Target

value

Unpurified

water

Target

value

BOD 50 10 40 10 40 10 50 12

SS 30 6 64 6 40 8 60 12

Water

quality

condition

(mg/l) NH4-N 20 1 9 1 25 1 20 1

Schedule Design/

Build 06/01～06/04～06/10 07/1/15～5/11～08/01 07/1～08/EOM 07/1～09/EOM

Organization for

design/build

DBO (Design, Build and Operation):

NSC, MWH, 正翔 DBB (Design, Bid and Build): NSC, MWH

Capacity of facility 3,710 ㎥ 4,390 ㎥ 2,513 ㎥ 39,550 ㎥

Table-2 Outline of 2 Projects and 4 Purification Plants



5. Future River Purification in Taiwan 5.1 Challenges of Design and Build (1) Points to be considered for transfer of technology of

river purification for overseas The water quality in East Asian nations such as Malaysia and Taiwan differs from Japan. The areas with inadequate sewerage have high-level of NH4-N. Therefore, measures against NH4-N to reduce N-BOD are essential when transferring river purification technology to the above nations.

(2) Water quality The four facilities in Taiwan have a highly polluted water of min. NH4-N=20mg/l. With our experience in the past, the purification of gravel contact oxidation process would be incapable of having much more. But we delivered as best design with confidence as we could that would show us another horizon in river purification technology through careful monitoring in the near future.

(3) Gravel resource Cobblestones of 50 to 200mm diameter are unavailable in Taiwan and it is difficult to get them in large quantity. Efforts need to be made to secure materials including gravel-/coble-stones for construction of gravel facilities.

5.2 Future Expansion The EPA in Taiwan intends to develop river purification facilities all over the country as a measure against river pollution. Starting with the four facilities, other river purification facilities will be constructed in various regions in the future. We will participate in future river purification projects in Taiwan and other nations utilizing our previous experience.

Contact: Tatsuo SHIMOMURA, Toshio KURASHIGE, Yoshio WATANABE, Noboru HAGIWARA Nihon Suido Consultants, Co.,Ltd River Engineering Department E-mail: [email protected] Fax: 042-584-7929 Web: http://www.nissuicon.co.jp

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