Simulation of tunneling construction methods of the Cisumdawu toll road

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1 Simulation of tunneling construction methods of the Cisumdawu toll road Muhamad Abduh, Sapto Nugroho Sukardi, Muhammad Rusdian La Ola, Anita Ariesty, and Reini D. Wirahadikusumah Citation: AIP Conference Proceedings 1903, (2017); View online: View Table of Contents: Published by the American Institute of Physics Articles you may be interested in Bidding cost evaluation with fuzzy methods on building project in Jakarta AIP Conference Proceedings 1903, (2017); / Evaluation of implementation viability gap funding (VGF) policy on toll road investment in Indonesia AIP Conference Proceedings 1903, (2017); / Construction safety monitoring based on the project s characteristic with fuzzy logic approach AIP Conference Proceedings 1903, (2017); /

2 Simulation of Tunneling Construction Methods of the Cisumdawu Toll Road Muhamad Abduh 1,a), Sapto Nugroho Sukardi 2,b), Muhammad Rusdian La Ola 2,c), Anita Ariesty 2, d) 1, e), Reini D. Wirahadikusumah 1 Associate Professor, Faculty of Civil and Environmental Engineering, Institut Teknologi Bandung, Jln. Ganesha No. 10, Bandung, 40132, Indonesia 2 Graduate Student, Faculty of Civil and Environmental Engineering, Institut Teknologi Bandung, Jln. Ganesha No. 10, Bandung, 40132, Indonesia a) Corresponding author: abduh@si.itb.ac.id b) saptosukardi@students.itb.ac.id c) rusdianlaola@students.itb.ac.id d) anitaariesty@students.itb.ac.id e) wirahadi@si.itb.ac.id Abstract. Simulation can be used as a tool for planning and analysis of a construction method. Using simulation technique, a contractor could design optimally resources associated with a construction method and compare to other methods based on several criteria, such as productivity, waste, and cost. This paper discusses the use of simulation using Norwegian Method of Tunneling (NMT) for a 472-meter tunneling work in the Cisumdawu Toll Road project. Primary and secondary data were collected to provide useful information for simulation as well as problems that may be faced by the contractor. The method was modelled using the CYCLONE and then simulated using the WebCYCLONE. The simulation could show the duration of the project from the duration model of each work tasks which based on literature review, machine productivity, and several assumptions. The results of simulation could also show the total cost of the project that was modeled based on journal construction & building unit cost and online websites of local and international suppliers. The analysis of the advantages and disadvantages of the method was conducted based on its, wastes, and cost. The simulation concluded the total cost of this operation is about Rp. 900,437,004,599 and the total duration of the tunneling operation is 653 days. The results of the simulation will be used for a recommendation to the contractor before the implementation of the already selected tunneling operation. INTRODUCTION Nowadays, a construction operation is demanded to be more effective and efficient in using resources with the aim to maximize the productivity of the construction operation itself. One way to reach that goal is to simulate the construction operation during the planning phase. The CYCLONE (Cyclic Operations Network) modeling technique is widely used for the simulation purpose because of its adaptability to cyclic construction operations, and because it is a convenient system to use [1]. The CYCLONE modeling emphasizes the logical sequence of construction activities and the effect of their interaction on productivity. For simulation purposes, the WebCYCLONE is a special purpose simulation software that could measure construction operation productivity with only require programming code based on construction operation based on the CYCLONE model [2]. The Cisumdawu Toll Road project is a strategic toll road project in Indonesia since this toll road becomes a continuation of the Java toll road plan that links the Cikampek-Palimanan toll road with the Padalarang-Cileunyi toll road, and then will connect two big cities in West Java Province, i.e., Bandung and Cirebon. One of the critical construction activities in this Cisumdawu Toll Road project is the 362-meter long tunneling operation. The tunneling operation is highly repetitive, and the most important activity is the actual advancement rate Proceedings of the 3rd International Conference on Construction and Building Engineering (ICONBUILD) 2017 AIP Conf. Proc. 1903, ; Published by AIP Publishing /$

3 of the tunnel. Using a simulation model developed for the tunnel, it is possible to investigate the impact of each important resource on the tunnel s advancing rate. The Cisumdawu toll road project is a 6-lane toll road divided into 2 tunnels of each 472 m long with a depth of 52.8 m. Tunnel construction is divided into 2 sections. The first section is a 110 m long tunnel portal located at the end of the tunnel that will be constructed using cut & cover method. Furthermore, the second section of 362 m long is planned to be constructed using New Austrian Tunneling Method (NATM) method. This paper presents a study of an alternative method of tunnel construction that could be used in Cisumdawu Toll Road Project for the contractor to be considered. The selected alternative method in the study is the Norwegian Method of Tunneling (NMT) which is suitable for the project. This study aimed to give measure the productivity of tunneling operation using NMT and analyze the advantages and disadvantages of NMT compared to the contractor s chosen method, the New Austrian Tunneling Method (NATM). A thorough literature search is conducted to select the suitable tunneling method and input data. Different simulation models were generated and run, and a sensitivity analysis was performed to show the effect of each variable on the tunnel advancement rate. STUDY METHODS The study was conducted as depicted in Fig. 1, and as follow: 1. Literature review and data collection. 2. Several literatures from international, journal, proceedings and magazines were reviewed to determine the alternative tunneling method and cycle time of processes associated with the selected method. The selection process to filter the literature was based on the correlation of the study and the similarity of work tasks that were integrated with the selected alternative method. Visit to the site several times were conducted to observe and collect field data. 3. Estimation of duration and cost. 4. Based on the literature and survey, the duration of each process was calculated and estimated, and the costs associated with the resources were determined. 5. CYCLONE modeling. 6. Based on the process of the selected method, a CYCLONE model was constructed and then translated the model into syntaxes and input for WebCYCLONE simulation. 7. Simulation run. 8. The validated model and input data were run in the WebCYCLONE site and then analyzed. 9. Sensitivity analysis. 10. Based on the result of simulation, a sensitivity analysis was performed to seek a productivity improvement for the selected method. 11. Conclusion. 12. The results from the simulation would be able to generate information about the cost and duration of the project. Compare the results with the contractor's plan to conclude the study. FIGURE 1. Methodology

4 ASSUMPTIONS FOR TUNNELING The NMT is most suitable for harder ground, where jointing and over break are dominant, and where drill and blasting are the most usual methods of excavation [3]. Since the geological condition of Cisumdawu Toll Road Project consists of silty clay and sandy clay (soft ground), therefore some adjustments should be made in order the NMT method could be applicable. The NMT uses Q-system as shown in Fig.2 for geological mapping and classification before selecting supports or reinforcements for the tunnel. FIGURE 2. Q-system for tunnel supports [3] The Q-system is based on 6 different parameters, and the Q-value is calculated by means of the following formula: where: RQD J n J r J a J w SRF = Rock Quality Designation = Joint Set Number = Joint Roughness Number = Joint Alteration Number = Joint Water Reduction Factor = Stress Reduction Factor Q= RQD J r J w J n J a SRF (1) Chryssanthakis et.al. [4] Conducted a research about NMT implementation in soft ground in Patas, Greece. The site consists marl and sand. Marl or marlstone is a calcium carbonate or lime-rich mud or mudstone which contains variable amounts of clays and silt. Due to lack of geological data to determine the Q-value in the Cisumdawu Toll Road project s location, it was assumed that the tunnel s geological condition in Cisumdawu Toll Road Project is similar to the Patas Project, therefore: Q= (2) Q=0,01 minimum -0,33(maximum) (3) Using conservative approach based on the above Q-values that were projected to the Q-system (Fig.2), an estimation of the support requirements is in category 8 where the installation of permanent support using B+S(fr), i.e., fiber reinforced shotcrete & bolting, and RRS, i.e., ribs reinforced concrete

5 The estimated Q-values could also determine the temporary support for the tunnel face. Since the range of the estimated Q-values is in all the tunnel face support criteria, thus the three criteria have the same possibility to be chosen in the simulation. The excavation sequence shown in Fig.3 where the upper part is the first part to be excavated. Maximum distance for excavation is 60 cm, this assumption based on the length of bolting which is 3 m with 5 partitions, 60 cm each that were installed as a temporary support. TABLE 1. Q-system for temporary support [5] Q-Value (Guiding) Support a Head of the Tunnel Face Pipe screening/jet grouting/freezing Boltingat face >0.2 Bolting at large blocks, almost horizontal stratification, low tension, and at outbreak FIGURE 3. Excavation sequence TUNNELING PROCESSES The tunneling processes are similar for both left and right ways tunnel. This operation consists of the following work tasks: 1. Perform a tunnel inspection to determine the Q-value for temporary tunnel support. 2. Install temporary tunnel support in accordance with the Q-value. 3. Perform excavation using excavator with 60 cm as maximum length of digging. 4. Perform scaling with excavator & labor crew. 5. Perform a tunnel inspection again to determine the Q-value for permanent tunnel support. 6. Install permanent tunnel support according to Q-value. 7. Repeat process 3 4 until excavation reaches 3 m. 8. Install precast tunnel wall using precast mounting machine as tunnel lining. 9. Move to the next section, repeat process 1 9 until 362 m tunnel constructed. Resource units needed in this tunneling operation are: 1. Tunnel Section. 2. Tunnel Surveyor. 3. Spilling Bolt. 4. Grouting Pump. 5. Ground Freezing. 6. Excavator. 7. Labor Crew. 8. Reinforced Rib of Shotcrete (RRS). 9. Fiber reinforced shotcrete & Bolting [B + S (fr)]. 10. Precast Concrete Tunnel Wall. 11. Precast Mounting

6 SIMULATION MODEL The modeling of this tunneling operation used the CYCLONE modeling technique, and the result of modeling could be found in Fig.4. Afterward, the model was translated into an input file for simulation using WebCYCLONE. This is a discrete event simulation methodology and was used for estimating tunneling advancement rate based on tunneling processes. 7 Ground Freezing Q= Tunnel Face Support Installation using Ground Freezing 3 Surveyor 10 Spilling Bolt 1 Section Ready 2 Tunnel Face Inspection 4 Determining Q-value for temporary support Q = Tunnel Face Support Installation using Bolting at face 16 Ready to Excavate GEN S 11 Grouting Pump 14 Spilling Bolt Q > Tunnel Face Support Installation using Bolting at large Blocks 15 Grouting Pump 17 Tunnel Excavation (max 60 cm) 19 Ready for Scalling 21 Tunnel Scalling 22 Scalling Finished 24 Tunnel Inspection 25 Determining Q- Value for permanent support ` 18 Excavator 20 Labor Crew 23 Surveyor 27 RRS 33 Precast Tunnel Wall 26 Q-Value determined 29 Permanent Support Installation 31 CON S 32 Support Installed 35 Tunnel Lining Move to the next section 30 Ready to Excavate 2 28 B+S(fr) 34 Precast Mounting FIGURE 4. CYCLONE model for tunneling operation using Norwegian Method of Tunneling (NMT)

7 Variable cost of each resource was modeled in Rupiah per hour and the estimation was made based on the 2016 national journal construction and building unit cost (Edition 35), the 2016 public work and human settlement ministry policy on unit cost analysis for construction works (28/Prt/M/2016), and online websites of local and international suppliers. The variable cost for each resource used in the model is provided in Table 3. Due to the tunnel construction in the Cisumdawu Toll Road project hasn t started yet, the duration of each work task used in the model was estimated based on literature review of similar work tasks that were performed in previous projects [6, 7, 8, and 9]. Some work tasks durations that weren t found in any literature were estimated based on its productivity from the equipment information, while some were assumed based on judgment. The duration for each work task used in the model are provided in Table 2. TABLE 2. Works tasks and duration for simulation model Work tasks Duration (minutes) Distribution Part 1 Part 2 Part 3 Part 4 Tunnel Face Inspection Beta ,50 Determining Q-Value Deterministic 15 Ground Freezing Deterministic 1080 Bolting at Face Installation Uniform Bolting at Large Blocks Installation Uniform Excavating Beta Scaling Uniform Tunnel Inspection Beta Determining Q-Value Deterministic 15 Permanent Support Installation Beta Tunnel Lining Deterministic 48 TABLE 3. Variable cost for simulation model Work Tasks Variable Cost (per hour) Surveyor Rp. 340,650 Ground Freezing Rp. 34,828, Spiling Bolt Rp. 525,661 Grouting Pump Rp. 150,000 Spiling Bolt Rp. 525,661 Grouting Pump Rp. 164,125 Excavator Rp. 312,175 Labor Crew Rp. 14,125 Surveyor Rp. 340,650 RRS Rp. 5,918,207 B + S(fr) Rp. 24,524,982 Precast Tunnel Wall Rp. 13,725,000 Precast Mounting Rp. 4,193,175 RESULTS The productivity for this operation was unit/min. The simulation defined 1 unit as 3 m of tunnel lining. If 1 work day is defined as 8 hours and both left and right tunnels were constructed at the same time, thus the duration of the tunnel construction: Productivity= (4) Productivity=0.554 m/day (5) Duration= 362 m m/day =653 days (6)

8 The cost per production unit for this operation is Rp 3,731,092, The simulation defined 1 unit as 3 m of tunnel lining. Thus, the cost of 2 tunnels with 362 m length in the Cisumdawu Toll Road Project: Total Cost=2 362 Rp 3,731,092, (7) 3 Total Cost=Rp 900,437,004,599 (8) The simulation also provides the idleness of each resource as depicted in Table 4. TABLE 4. Resource idleness statistics Name Type Average Max Idle Times Not Total Sim Average Units at % Idle Units Idle Units Empty Time Wt Time End Section Ready QUEUE Surveyor QUEUE Q=0,001-0,02 QUEUE Ground Freezing QUEUE Q=0,02-0,2 QUEUE Spilling Bolt QUEUE Grouting Pump QUEUE Q>0,2 QUEUE Spilling Bolt QUEUE Grouting Pump QUEUE Ready to Excavate GEN Excavator QUEUE Ready for Scaling QUEUE Labor QUEUE Scaling Finished QUEUE Surveyor QUEUE Q-Value Determined QUEUE RSS QUEUE S(FR) QUEUE Ready to Excavate 2 QUEUE Support Installed QUEUE Precast Tunnel Wall QUEUE Precast Mounting QUEUE The productivity chart for 100 cycle s simulation is shown in Fig. 5, the productivity reaches steady state

9 FIGURE 5. Productivity chart for tunneling operation using NMT for 100 cycles DISCUSSION Norway and Austria are two major countries that have long traditions in using shotcrete and rock bolts for tunnel support. Yet there are significant differences in philosophy and areas of application for NATM and NMT. The NATM is most suitable for soft ground where the ground can be machine or hand excavated, where jointing and over break are not dominant. The NMT is most suitable for harder ground, where jointing and over break are dominant, and where drill and blasting are the most usual methods of excavation [3]. The NMT uses Q-system for geological mapping and classification to determine the tunnel supports. The Q-system is a forward predictive method and therefore differs significantly from NATM methods, which apparently depend on monitoring to decide on the timing and amount of additional support to classify its geological condition. The important point is that forward prediction of conditions and agreed modifications for unexpected conditions should each be done as early and as accurately as possible to minimize disputes and tunnel instability. The NATM recommends and applies primary S(mr) (mesh reinforced shotcrete), in the case of NMT the choice is S(fr) (fiber reinforced shotcrete), which is essential for actively supporting rock with over-break, instead of leaving inevitable voids and 'shadows' when reinforcement is applied in the form of mesh instead of as fibers [9]. FIGURE 6. The difference between S(mr) (left) and S(fr) (right) [9] Lattice girders and steel arches that are usually used in NATM cannot be used in NMT. They will attract extra deformation and cause failures when they are applied as part of the Q-system. Moreover, the use of S(mr) attracts deformation, and can even be dangerous, as it is an inefficient, multi-process and therefore delayed support measure. In unstable rock, arches of S(fr) can be built rapidly by robot application (with non-alkali accelerator). The arches are

10 then systematically bolted and internally reinforced with steel bars. These composite RRS (rib reinforced shotcrete) arches are inevitably far superior to lattice girders or steel arches [9]. TABLE 5. Sensitivity analysis Number of Number of Labor Productivity Per Unit Excavator Crews Time Cost Per Unit Time Cost Per Prod Unit Rp Rp , Rp Rp Rp Rp Rp Rp Rp Rp Rp Rp Rp Rp Rp Rp Rp Rp Based on the results of the simulation, using NMT would make the operation faster than the NATM that is planned by the contractor. The difference total duration between the two methods is 203 days. The acceleration of the tunnel construction using NMT in the simulation occurs because of these reasons: 1. The implementation of Q-system 2. Q-system could predict the geological condition of the tunnel to prevent delay. 3. The usage of precast tunnel wall for tunnel lining 4. Precast tunnel wall doesn t take time to settle like the cast on site lining. 5. Work task duration 6. The duration of each work task used in the model was based on the literature review, machine productivity, and judgment, thus the productivity of the work task probably could not represent the actual condition on the site. 7. Assumptions used in simulation 8. Simplification and assumption of construction process that were applied to the model affects the results of the project duration. In this study, a sensitivity analysis was conducted by changing numbers of excavator and labor to improve the productivity of the operation. The results, as shown in Table 5, concludes that the number of excavator and labor will not affect the productivity of the tunneling operation. This can be explained due to the nature of sequential operation of tunneling; a work task in the operation needs to wait for the predecessor work task to be done to begin. As a result, the idle of machines and workers are above 70%. That could explain why changing the numbers of machines or workers will not affect the productivity of tunneling construction significantly. Due to lack of field data during the study and site visit because of the tunnel construction hasn t begun yet, the result of this study should be seen only as an alternative plan. There should be more extended study regarding the resources and the geological conditions needed in the NMT method in order this method could be applicable in the Cisumdawu Toll Road project, especially for decision making process before the tunneling construction starts. CONCLUSIONS This paper presents a study on simulation of the tunneling operation using NMT in the Cisumdawu Toll Road project. This study is expected to be an example for consideration and education for contractor, student, and researcher in construction engineering field. The simulation concluded the total cost of this operation is about Rp and the productivity for this operation is m/day that makes total duration for the tunneling operation is 653 days; which is 203 days faster than the NATM method that is chosen by the contractor. The acceleration of the tunnel construction using NMT in the simulation occurs because of the implementation of Q-system, the usage of precast tunnel wall for tunnel lining, work task duration, and assumptions used in simulation. Moreover, changing the numbers of machines or workers won t affect the productivity significantly due to the nature of sequential processes of tunneling construction operation

11 ACKNOWLEDGEMENTS This study was a final project in a course, entitled Planning and Analysis Construction Operation, offered in Construction Engineering and Management Graduate Program in Civil Engineering, Faculty of Civil and Environmental Engineering, ITB, Indonesia. This study was fully supported by the Institut Teknologi Bandung. We would also like to show our gratitude to the Project Implementation Unit of the Cisumdawu Toll Road Project, the Ministry of Public Works and Human Settlement, and the contractors MCC WIKA NINDYA WASKITA Joint Operation which provided data, insight, and expertise that greatly assisted the study. We also thank our class-mate in this course for the support during the study. REFERENCES 1. Halpin, D.W., Planning and Analysis of Construction Operation (John Wiley and Sons, Inc., Canada, 2002). 2. Halpin, D.W., Senior, A.B., WebCYCLONE User s Manual. Construction Management (John Wiley and Sons, Inc., Hoboken, 2011) 3. Barton, N., Norwegian Method of Tunneling. World Tunneling (1992). 4. Chryssanthakis, P., Barton, N., Loset, F., Dallas, A., Mitsotakis, K., 8th International IAEG Congress. (1998). 5. Norwegian Tunneling Society, Rock Support in Norwegian Tunneling Publication No. 19. (NFF, Oslo, 2010). 6. Park, N.J., Kim, H.S., Moon, H., Kang, L., Korean Society of Civil Engineers, 32, (2012). 7. Guo, S.J., Can. J. Civ. Eng. 28, (2001). 8. Vargas, J.P., Koppe, J.C., Perez, S., Hurtado1, J.P., Planning Tunnel Construction Using Markov Chain Monte Carlo (MCMC), Hindawi Publishing Corporation Mathematical Problems in Engineering (2015). 9. Barton, N., TAC Workshop Support Pre-Injection (2013). 10. Barton, N., Forty Years with the Q-System in Norway and Abroad, Bergmekanikk/Geoteknikk (2014)