Investigation on Deformation Behavior of the Crossing Section of Two Municipal Road Tunnels during Construction  
[PERSON]  
1 School of Civil Engineering, Central South University, Changsha 410075, China 1 [PERSON]  
2 Hefei Urban Planning & Design Institute, Hefei 230041, China 2 [PERSON]  
1 School of Civil Engineering, Central South University, Changsha 410075, China 1  
[PERSON]  
2 Hefei Urban Planning & Design Institute, Hefei 230041, China 2 [PERSON]  
Experimental study is an effective method to reveal the mechanical behavior of a geotechnical structure [11; 12; 13; 14; 15]. In particular, the field test results are generally regarded as the most valuable first-hand information [16]. [PERSON] et al. [17] studied the response of the Taipei Rapid Transit System Tunnel caused by adjacent excavation, which was a reference for the establishment of an excavation standard. [PERSON] et al. [18] monitored the deformation of the Mass Rapid Transit tunnel during a large excavation nearby, and the influence of the stiffness of the tunnel lining on the displacement and distortion was discussed. [PERSON] et al. [19] investigated the influence of a nearby excavation in soft soils on the existing Ningbo Metro Line 1 tunnels through field monitoring. [PERSON] et al. [20] focused on engineering measures to reduce the effect of adjacent excavation via three groups of centrifuge tests. [PERSON] et al. [21] conducted several centrifuge tests on the interaction between adjacent foundation pits with an aim to provide some suggestions for reducing the adjacent excavation effect.  
The model geometry and model parameters can be easily changed as required in numerical analysis. Consequently, numerical simulation is regarded as a powerful and economical method to reveal the mechanical behavior of a geotechnical structure [22; 23; 24]. [PERSON] et al. [25] established a pipe-soil coupling model to investigate the excavation effect of a foundation pit adjacent to a hydrogen pipe. [PERSON] et al. [26] investigated the effects of unilateral excavation near a metro station, and a physical model test and discrete element method were adopted to analyze the influence of station width and excavation depth. [PERSON] et al. [27] evaluated the tunnel deformation law and soil stress distribution by hypo-plastic model analysis under different excavation locations of foundation pits. [PERSON] et al. [28] studied the deep excavation behavior of a pit adjacent to a flexible retaining wall, and the influences of excavation depth, wall depth and bending rigidity on the mechanical behavior of a retaining wall were studied by numerical simulation. [PERSON] et al. [29] sought the best supporting measure for a foundation pit that enhanced the stability of adjacent tunnels based on a simulation of the whole excavation process. [PERSON] et al. [30] established a 3-D numerical model to study the effect of triangular-distribution tunnel excavation on surface settlement and tunnel stability.  
The above research works are beneficial to the development of tunnel construction technology. However, the geological conditions of engineering vary greatly from site to site. Moreover, few studies have been carried out with respect to the tunnel crossing section, which is regarded as a more complicated condition. In this study, an analysis model of the crossing section of two municipal road tunnels is established by using the ABAQUS finite element platform based on a construction project of the Huayuan Road Tunnel and Luzhou Road Tunnel in Hefei City, China. Two construction measures (i.e., symmetrical and asymmetrical construction processes) are designed to investigate the deformation behavior of the crossing section during the construction of the connecting part for comparison.