IRJET- Comparative Study of Top down & Bottom up Method Construction Schedule with respect to Co

International Research Journal of Engineering and Technology (IRJET)

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Volume: 06 Issue: 02 | Feb 2019

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Comparative Study of Top down & Bottom up Method Construction Schedule with Respect to Construction of a Residential Building Rafi Sakharkar1 1P.G

Student & Construction Engineer, Department of Civil Engineering Shivajirao S. Jondhle College of Engineering & Technology & Catapult Realty Consultants, Mumbai (India) ---------------------------------------------------------------------***---------------------------------------------------------------------

Abstract - The rapid increase in the construction sector

of project affected peoples etc. Though some of the associated problems faced in the developments cannot be resolved through the use of advanced technology there is a wide scope in technological advancements that can be adopted to counter the time over runs caused by the stated factors.

all around the globe has led to significant changes in the methodologies and techniques being adopted to cater to the modern requirements of the projects that are being executed. This has led to make the best use of land available and a substantial increment is seen with respect to utilization of underground structures for metros, high-speed railway corridors as well as residential and commercial structures. The general perspective regarding the construction activities are changed and a detailed planning, designing and monitoring approach has led to further advancements in methods that are being incorporated to complete the projects in effective, economic and efficient manner. “Top down Construction Method” is recent trend that is being adopted for infrastructural projects and its applicability for housing projects is being reviewed in this paper with reference to a building being constructed by traditional bottom up method in Mumbai.

When we talk about the construction industry the resources incorporated in completion of proposed works are time, capital, manpower and space. With the right and justified use of these resources a significant efficiency and economy can be achieved.

The construction activities from ancient age have a typical stage of commencement during the execution phase i.e. the first activity starts from the foundation of the structure. The conventional method of construction of structures is based on Bottom-Up method in which the sub-structure and super-structure floors are constructed sequentially from the bottom of the sub-structure or lowest level of basement to the top of the super-structure.

This method is suitable for small scale works, as there is rapid change in patterns of use of land available like use of underground basements for parking, underground metro stations the volume of works at the foundation level of the structures has increased to manifolds. In this context the construction industry experts has started to adopt a new Top Down method for better utilization of resources available.

Key Words: Top down Construction, Deep basement excavations, Residential building.

1. INTRODUCTION The current scenario of construction industry sector emphasizes on the timely delivery of the projects whether it be any infrastructural developments, residential/commercial building structures or any other civil works. There are various factors that affects the completion times of projects ranging from availability of funds to political issues, environmental laws, resettlement

2. Construction Schedule of a residential building with deep basement using conventional bottom up technique.

A Construction schedule study was conducted with respect to the general output of work being observed and the number of man hours incorporated to complete the construction of various civil works of a residential building which consist of 9m deep basement and 20 upper habitable floors having a plot area of about 800 Sq.mt, basement area of 530 Sq.mt and superstructure built-up area of 7200 Sq.mt. The residential building project was located in Central Mumbai and major works were completed. The construction schedule is as shown in the Table 1.

ID

WBS

Task Name

Duration

Start

Finish

Predecessors

1 2 3

1 1.1 1.2

PROJECT DURATION BORING, CASTING OF SHORE CASTING OF CAPPING

557 days 51 days 10 days

01/06/17 01/06/17 22/07/17

15/12/18 21/07/17 31/07/17

3

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e-ISSN: 2395-0056

Volume: 06 Issue: 02 | Feb 2019

p-ISSN: 2395-0072

4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27

1.3 1.4 1.5 1.6 1.6.1 1.6.2 1.6.3 1.6.4 1.6.5 1.6.6 1.7 1.7.1 1.7.1.1 1.7.1.2 1.7.1.3 1.7.2 1.7.2.1 1.7.2.2 1.7.2.3 1.7.3 1.7.3.1 1.7.3.2 1.7.3.3 1.8

28

1.9

29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

1.9.1 1.9.2 1.9.3 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28 1.29 1.30 1.31

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PERIPHERAL EXCAVATION ROCK ANCHORING & FIXING EXCAVATION FOR BOTTOM FOUNDATION OF CIVIL PCC REINFORCEMENT WORKS SHUTTERING WORK COLUMN VERTICAL CHECKING OF WORK CONCRETING COLUMN CASTING UPTO 1ST LIFT REINFORCEMENT SHUTTERING WORKS CONCRETING 2ND LIFT REINFORCEMENT SHUTTERING WORKS CONCRETING 3RD LIFT REINFORCEENT SHUTTERING WORKS CONCRETING RETAINING WALL BASEMENT SLAB REINFORCEMENT BASEMENT SLAB SHUTTERING BASEMENT SLAB SUPPORTS BASEMENT SLAB 1ST SLAB 2ND SLAB 3RD SLAB 4TH SLAB 5TH SLAB 6TH SLAB 7TH SLAB 8TH SLAB 9TH SLAB 10TH SLAB 11TH SLAB 12TH SLAB 13TH SLAB 14TH SLAB 15TH SLAB 16TH SLAB 17TH SLAB 18TH SLAB 19TH SLAB 20TH SLAB TERRACE SLAB OHT,LMR

14 days 20 days 66 days 33 days 5 days 22 days 7 days 2 days 1 day 4 days 10 days 4 days 2 days 3 days 2 days 4 days 2 days 3 days 2 days 4 days 2 days 3 days 2 days 40 days

01/08/17 16/08/17 05/09/17 01/11/17 08/11/17 01/11/17 20/11/17 27/11/17 29/11/17 30/11/17 04/12/17 04/12/17 04/12/17 04/12/17 06/12/17 07/12/17 07/12/17 07/12/17 09/12/17 10/12/17 10/12/17 10/12/17 12/12/17 14/12/17

14/08/17 04/09/17 10/11/17 03/12/17 12/11/17 22/11/17 26/11/17 28/11/17 29/11/17 03/12/17 13/12/17 07/12/17 05/12/17 06/12/17 07/12/17 10/12/17 08/12/17 09/12/17 10/12/17 13/12/17 11/12/17 12/12/17 13/12/17 22/01/18

35 days

08/01/18

12/02/18

30 days 7 days 1 day 25 days 20 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 30 days

08/01/18 05/02/18 12/02/18 13/02/18 10/03/18 30/03/18 11/04/18 23/04/18 06/05/18 18/05/18 30/05/18 11/06/18 23/06/18 05/07/18 17/07/18 29/07/18 10/08/18 23/08/18 04/09/18 16/09/18 28/09/18 11/10/18 23/10/18 04/11/18 16/11/18

07/02/18 11/02/18 12/02/18 09/03/18 29/03/18 10/04/18 22/04/18 05/05/18 17/05/18 29/05/18 10/06/18 22/06/18 04/07/18 16/07/18 28/07/18 09/08/18 22/08/18 03/09/18 15/09/18 27/09/18 10/10/18 22/10/18 03/11/18 15/11/18 15/12/18

4 5 6 7FF+2 days 9FF+10 10FF+4 11 12 13

14 17FF+1 day 18FF+1 day 19FS-1 day 21FF+1 day 22FF+1 day 23FS-1 day 25FF+1 day 26FF+1 day

0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days

31FF+15 33FF+4 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56

0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days

Table 1

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e-ISSN: 2395-0056

Volume: 06 Issue: 02 | Feb 2019

p-ISSN: 2395-0072

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From the above construction schedule it is evident that up to the activity 1.9.3 i.e. “casting of basement slab” in the WBS the super structure works cannot be executed. The total project duration is of 557 days all the activities up to the duration of 254 days are critical for commencement of superstructure activity.

2.2 Use of advanced techniques in traditional top down construction method.

form of stanchions, shore pile, retaining wall, and basement raft. One essential element in the top down technique is the use of diaphragm wall[1] as the retaining structure hence based on the use of retaining structure in the form of widely used shore pile & retaining wall or the diaphragm wall this technique is further subdivided into up-down, semi top down approach as discussed by S.S Basargar[1].Many Infrastructural developments are done with the use of this technique in India as well as other countries which includes car parking facilities in Delhi[1],Metro rail stations in Delhi & Kolkata[1],Santorani Square building in Ahmedabad[2], Royal Charoen Krung in Bangkok[3] etc. The use of this method is done mainly in infrastructural developments in India whereas in other places residential buildings are built using this method.

As the construction speed is required to be optimised to achieve time savings in recent times the use of advanced formworks and advanced materials which allows the construction time to be reduced is incorporated. Use of Alsina formwork for construction of columns, retaining wall reduces the time required in shuttering but these are not widely used due to their limited application in single project and increased refurbishment costs. Also to reduce the slab cycle duration particularly in residential housing projects use of advanced mivan formwork is adopted for large scale mass housing projects. Since these advanced formwork are not suitable for a standalone building structure due to its investment costs there is a little scope in achieving time savings with the use of conventional construction materials.

The adoption of this technique in residential segment around Mumbai is done by developers like SD corp at one of their project named Samta nagar redevelopment in Kandivali & Lodha group at one of their project named New Cuffe Parade the results of which are quite satisfactory and partially justifies the suitability of this technique to a larger section of residential developments where deep basement is provided, structure height restrictions are prevalent, speedy handover of the work is required.

3. Application of top down construction method.

The prime objective of the Top Down Construction Method implementation is to reduce the time required to construct the structures which have a significant volume of work required to be done below the ground level and simultaneously work on the superstructure part so that both the components can be completed leading to timely delivery of the proposed projects. The scope of use of Top down Construction is widespread, it is a completely different approach from conventional method and hence right from the project conceptualization phase to hand over phase each and every activity is required to be altered. The use of this method required prompt project management skills, advanced structural designing’s, use of geotechnical advancements and engagement of special equipment to execute the work. Proper execution of the works is a perquisite for achieving the success by top down method as the method is based on practical application rather than laboratory based experiments.

3.2 Estimated Construction Schedule of the residential building discussed above using top down construction technique.

A Construction schedule study was conducted with respect to the general output of work being observed and the number of man hours that are expected to be incorporated to complete the construction of various civil works of a residential building which consist of 9m deep basement and 20 upper habitable floors having a plot area of about 800 Sq.mt, basement area of 530 Sq.mt and superstructure built-up area of 7200 Sq.mt. The residential building project was located in Central Mumbai and major works were completed. With inputs from experienced construction engineers & managers and also the general output of machine & labours the estimated construction schedule is as shown in the Table 2.

3.1 Top Down construction TechniqueThe Top down construction technique eliminates the need of excavation at initial stages and allows the work to be done in superstructure without completion of substructure works except the foundation works in the ID 1 2 3

WBS 1 1.1 1.2

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Task Name PROJECT DURATION DIAPHRAGM WALL PREPARATION OF PRE

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Duration 379 days 35 days 30 days

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Start 01/06/17 01/06/17 01/06/17

Finish 18/06/18 05/07/17 30/06/17

Predecessors

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4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38

International Research Journal of Engineering and Technology (IRJET)

e-ISSN: 2395-0056

Volume: 06 Issue: 02 | Feb 2019

p-ISSN: 2395-0072

1.3 1.4 1.5 1.5.1 1.5.2 1.5.3 1.6 1.6.1 1.6.2 1.6.3 1.6.4 1.6.5 1.6.6 1.7 1.8 1.9 1.10 1.11 1.12 1.13 1.14 1.15 1.16 1.17 1.18 1.19 1.20 1.21 1.22 1.23 1.24 1.25 1.26 1.27 1.28

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DRILLING OF PILES INSTALLATION OF STANCHIONS BASEMENT SLAB BASEMENT SLAB SHUTTERING BASEMENT SLAB BASEMENT SLAB CONCRETING FOUNDATION OF CIVIL WORKS EXCAVATION FOR BOTTOM PCC REINFORCEMENT WORKS SHUTTERING WORK CHECKING OF WORK CONCRETING 1ST SLAB 2ND SLAB 3RD SLAB 4TH SLAB 5TH SLAB 6TH SLAB 7TH SLAB 8TH SLAB 9TH SLAB 10TH SLAB 11TH SLAB 12TH SLAB 13TH SLAB 14TH SLAB 15TH SLAB 16TH SLAB 17TH SLAB 18TH SLAB 19TH SLAB 20TH SLAB TERRACE SLAB OHT,LMR

12 days 12 days 34 days 30 days 7 days 1 day 87 days 66 days 5 days 22 days 7 days 1 day 4 days 25 days 20 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 12 days 30 days

29/06/17 01/07/17 13/07/17 13/07/17 08/08/17 16/08/17 17/08/17 17/08/17 20/10/17 13/10/17 01/11/17 08/11/17 09/11/17 17/08/17 11/09/17 01/10/17 14/10/17 26/10/17 07/11/17 19/11/17 01/12/17 13/12/17 25/12/17 06/01/18 18/01/18 31/01/18 12/02/18 24/02/18 08/03/18 20/03/18 01/04/18 13/04/18 25/04/18 08/05/18 20/05/18

10/07/17 12/07/17 16/08/17 11/08/17 14/08/17 16/08/17 12/11/17 22/10/17 24/10/17 03/11/17 07/11/17 08/11/17 12/11/17 10/09/17 30/09/17 13/10/17 25/10/17 06/11/17 18/11/17 30/11/17 12/12/17 24/12/17 05/01/18 17/01/18 30/01/18 11/02/18 23/02/18 07/03/18 19/03/18 31/03/18 12/04/18 24/04/18 07/05/18 19/05/18 18/06/18

2FF+5 days 4FF+1 day,3 5 7FF+3 days 8FF+1 day 9 11FF+2 days 12FF+10 days 13FF+4 days 14 15 9 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37,16

1 day 0 days 0 days 0 days 0 days 0 days 186 days 186 days 186 days 186 days 186 days 186 days 186 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days 0 days

Table2 From the above construction schedule it is evident that up to the activity 1.5.3 i.e. “casting of basement slab” in the WBS the super structure works cannot be executed. The total project duration is of 379 days all the activities up to the duration of 76 days are critical for commencement of superstructure activities.

4. Comparison of construction schedule of top Down & Bottom up method Sr No

1 2

Description Foundation Works Upton Plinth Superstructure Works

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Duration (Days) Top Down Bottom Up Method Method 76

Total Duration Top Down Bottom Up Method Method

254

20

46

303

80

54

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379 303

Impact Factor value: 7.211

% duration Engaged Top Down Bottom Up Method Method

557

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Volume: 06 Issue: 02 | Feb 2019

p-ISSN: 2395-0072

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Comparative study of both the schedules deciepts that the project duration can be reduced by adopting top down method also the foundation work quantum is reduced substantially as compared to bottom up method albeit the complexity and nature of work becomes a little difficult.

[6] Site visit at SD corp Samtanagar redevelopment project Kandivali,Mumbai.

[7] Site visit at Lodha New Cuffe Parade, Mumbai [8] Reviews from construction managers & engineers of reputed companies like SD Corp , Lodha, Catapult Realty.

3. CONCLUSION The time savings are eminent with the use of the top down construction method whether it is an infrastructural or residential work. The time overruns can be reduced up to 30% which itself is a great relief in housing project. Also the important element that is diaphragm wall& stanchions construction eliminates the tedious foundation works which can compensate the additional cost that are required to be incurred for special equipment usage. One more advantage of using this technique is that underground areas are utilized to a better extent reducing the number of podium floors that are generally provide in buildings for parking without affecting the construction schedule. One more important benefit is that the height of superstructure can be maintained without affecting the habitable floor counts in height restricted zones near airports or other areas of strategic importance.

REFERENCES [1] Emerging Trend in Deep Basement Construction: TopDown Technique by S. S. Basarkar1, Manish Kumar2, B.G. Mohapatro3 P.R. Mutgi4, 1 General Manager, ITD Cementation India Limited, Mumbai, India. 2 Vice-President, ITD Cementation India Limited, Mumbai, India. 3 Professors, School of Civil Engineering, KIIT University, Bhubaneswar, India. 4 Principal, J.J. Magnum College of Engineering, Jaysingpur, India .

[2] Heritage infra space Private Limited.

[3]Comparative Study of Construction Technology for Underground Metro Stations in India by Virendra Kumar Paul1, Salman Khursheed2, Rohit Singh3 ,1 Professor & Head, Department of Building Engineering & Management, SPA, Delhi, India. 2 Assistant Professor, Department of Building Engineering & Management, SPA, Delhi, India. 3 Practicing Project Manager .

[4] Research and Design on Top-Down Method for Large Scale Podium Basement Excavation of Shanghai Tower Jian Jia, XiaoLin Xie, JieQun Zhai, Yu Zhang, Ke Yang and XiaoHang Guo [5] Performance of Diaphragm Wall Constructed Using Top Down Method by Chang-Yu Ou , Member ASCE, JuiThng Liao and Horn-Da Lin, Member ASCE.

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