## 2 Testing the Cho'ponota L1 Bridge
### Digital Twin Construction: Experimental Setup, Field Instrumentation, and Modeling Interface
Initial material properties were assigned according to project specifications: C50/60 concrete for the deck, C30/35 for the piers, and C25/30 for the foundations and piles, with corresponding elastic modulus values based on standard code formulations. Boundary conditions were defined by incorporating elastic spring supports  
Figure 2: Test-assisted digital twin framework for the Cho’ponota L1 Bridge. at the foundation level to simulate partial fixity and the pile-soil interaction effects, while elastomeric bearings were modeled through translational and rotational springs reflecting their stiffness characteristics. The self-weight of structural components was automatically included, and additional superimposed dead loads such as pavement, barriers, and utilities were applied according to construction documentation. This model was acquired and utilized for the evaluation of the current structural condition of the bridge and the planning of test procedures. Figure 3 presents several visuals of the finite-element model. As part of the study, static and dynamic load tests were conducted to evaluate the structural behavior of the Cho'ponota L1 Bridge. Two trucks, weighing 30 tons and 50 tons, were used during the tests. The bridge consists of four spans, and during the static load tests, displacement values were measured at designated points on spans S1, S2, and S3. Displacement data for the static tests were obtained using geodetic measurement methods with a total station (Leica Flexline TS07, Leica Geosystems AG, Heerbrugg, Switzerland). In the dynamic load tests, acceleration values were measured at designated points on spans S1, S2, and S3. These acceleration data were recorded using six accelerometers (Type 8340, Bruel & Kjaer, Narum, Denmark) installed on each span and collected through a the data acquisition unit (Type 3560C, Bruel & Kjaer, Narum, Denmark). Dynamic displacement values at that moment were derived from the measured acceleration data. The plan and section views of the measurement points are presented in Figure 4.  
A naming format has been established to record data from the measurement points. As shown in Figure 4, the spans are labeled as S (with three spans: S1, S2, and S3), and each span's start, middle, and end locations are labeled as L (L1, L2, and L3). Each location consists of five points. In the naming format SA-LBC, A represents the span number, B indicates the location number, and C corresponds to the point number within each location. For example, S2-L31 refers to span number 2 (S2), location number 3 (L3), and point number 1. This is illustrated in Figure 4.  
Figure 3: Finite-element model of the Cho’ponota L1 Bridge. In the static and dynamic vehicle load tests, 28 and 24 different loading scenarios were considered, respectively, and a format for the load conditions were established. Upon examining the finite-element model of the bridge, it was observed that the design considered the H30S24 (54 t) and NK100 (100 t) vehicle loads. However, during the construction phase, regular displacement measurements conducted by the authorities indicated that displacement values exceeding the design limits were obtained at span S2. Considering this issue and to prevent potential damage, it was decided to use vehicles with lower weights than those specified in the design during the tests. Following the tests, the finite-element model will be updated, and analyses will be repeated under the design loads. For the vehicle load tests, two truck vehicles (Shacman F3000, Shaanxi Automobile Group Co., Ltd., Xi'an, China) weighing 30 tons (A1) and 50 tons (A2) were used. During the static vehicle load tests conducted on spans S1, S2, and S3, each vehicle (A1 and A2) was stopped for 10 min at different locations in each lane (lane 1 (right) and lane 2 (left)) to take measurements. For the static load tests, 28 different loading scenarios were created based on the span number (S), vehicle type (A), lane region (B), and location (L).