## 1 Introduction  
In tunnel construction, it is typical to compare the advantages and disadvantages of two major methods, drill and blast (D&B), and TBM, in the planning or design stage. Essentially, a tunnel excavation method is chosen as a result of interaction among various elements such as safety, cost and time schedule [1]. The construction time is an important factor in the selection of the construction scheme (number of construction lots and intermediate construction access) and the construction method (excavation method, lining system) [2]. Hence, for a TBM tunnel, many studies focused on estimating advance rates [3, 4, 5, 6, 7, 8, 9], and thus CSM model [10], NTNU model [11], Q\({}_{\text{TBM}}\)[12], etc., were established. Meanwhile, the D&B method is a very flexible and adaptable process with respect to the excavation of intermediate cross sections or cross sections of any shapes and sizes, and it has advantages in installing the various types of primary rock supports such as shotcrete, wire-mesh, rock-bolt and forepoling. Furthermore, D&B has a short time-mobilisation, as standard equipment is used during the excavation, and has a lower advance rate (performance rate) in most cases, compared to the TBM technology [13]. For a D&B tunnel, some researchers also studied and suggested the usual advance rate of a D&B tunnel. [PERSON] (2017) found that in tunnelling by the New Austrian Tunnelling Method (NATM), the average daily advance rates could reach 10 to 15 m in favourable rock conditions with peak rates up to 20 m/day. Even in poor conditions (e.g., in fault zones),rates of 2 to 3 m/day are possible due to the high flexibility of the method. In crushed zones, it can be easier than TBM to advance due to the high versatility of the method [3], and the advance rate of D&B in a good rock mass is usually 6 m/day [14] or generally 3-9 m/day [15] Hence, when analysing or mentioning advance rates, geological conditions always need to be taken into account. In addition, some previous studies estimated the construction time or advance rate for the D&B method. [PERSON] et al. [16; 17] suggested Decision Aids for Tunnelling (DAT), a computer-based simulation tool used to determine tunnel construction cost and time through a probabilistic approach. [PERSON] et al. [18] also suggested a probabilistic model considering the uncertainties in geotechnical conditions, excavation performance, and the risk of extraordinary events based on the Dynamic Bayesian Network technique to estimate tunnel construction time. [PERSON] et al. [19] simulated the operations of NATM (New Austrian Tunnelling Method) to analyse the productivity and sensitivity of the method using CYCLONE softwares. [PERSON] and [PERSON] [20] defined the time needed for any particular process using the drill and blast tunnel excavation method with 737 field measurements, concluding that the best construction performance is reached when distance from tunnel adit and tunnel face is smaller than 200 meters. [PERSON] et al. [21] estimated the tunnel construction time for three tunnels by using the Korean Standard of Construction Estimate, which is usually applied to tunnel design in Korea and was established on a deterministic basis, and the results showed differences of between 7% and 50% from the actual operation times. Meanwhile, in Norway, the model for prediction of advance rate as well as excavation cost of D&B tunnels has been developed since 1975 [22; 23; 24], which is called a NTNU D&B prediction model. This is an empirical prediction model established on the basis of a substantial amount of field data from various subsurface excavations such as road and railway tunnels, hydropower, and rock caverns in Norway [25; 26]. Using the NTNU model, the productivity and efficiency of the D&B and TBM options for excavating certain size tunnels were also examined [27].