# Research on Optimization Design of Tunnel Blasting Scheme Adjacent to Buildings
## 1 Introduction  
The rapid development of urbanization has brought on great pressure to the traffic of cities, which can be effectively alleviated by the urban underground rail transit system traffic pressure. As an important part of subway engineering, the design and construction of subway tunnels are restricted by many factors, such as geological conditions and the surrounding environment [1; 2; 3; 4]. The drilling-and-blasting method, the most commonly used method for tunnel construction, is low cost and effective [5; 6; 7; 8; 9; 10; 11]. However, in the construction process of blasting control sections, the advantages and disadvantages of the blasting design programs will directly affect the quality of the blasting construction [12; 13]. The shallowly buried strata of Qingdao, Dalian and other areas are dominated by miscellaneous fill, clay, sand, granite and tuff with different degrees of weathering, and all them show obvious characteristics, being soft on the top and hard on the bottom [14]. Whensubway tunnel construction is carried out on this type of strata using the shallow subway excavation method, the rock bodies in the upper and lower sections of tunnels are often found to be very different. The surrounding rocks in the upper section are weak and easily broken, sometimes even with poorly stabilized sand layers, while those in the lower section are intact and hard. In these formations, if a single drilling-and-blasting method is used for excavation, not only is the process cumbersome, making accurate blasting difficult, but it is also very easy for the softer upper strata and adjacent buildings to cause greater disturbance, which leads to an excessive deformation of the surrounding rocks or even to surface and tunnel collapse [15; 16]. Recently, in terms of blasting vibration control in shallow urban subway tunnels, scholars have carried out a great deal of research through numerical modeling and on-site monitoring. [PERSON] [17] used numerical simulation and on-site monitoring to study the Chongqing Light Railway Daping Station, determining the shallow holes' multi-circulation, division excavation, and additional peripheral shock absorbing holes, as well as the strict control of the number of dregs and other measures to provide an important basis for the determination of construction parameters and blasting parameters of large sections of urban tunnels under complex conditions. [PERSON] [18] fit the coefficients in [PERSON]'s formula based on field monitoring data to make a prediction of the blasting velocity of neighboring buildings, meanwhile timely adjusting the blasting parameters during construction to provide a reference for the subsequent blasting construction scheme design. [PERSON] [19], aiming at the Yichang Expressway Tunnel, proposed the double-sidewall guide pit method for the blasting and excavation scheme of class V perimeter rocks, which was used for tunnels underneath buildings, and a good blasting effect was obtained. [PERSON] [20] combined the Shanghai Fuxing East Road Tunnel project, blasting three sections of diaphragm walls in four sections, which ensured the stability of the structure underneath the tunnel. [PERSON] [21] addressed the issue of buildings over the Anliu High-Speed Railway Tunnel and proposed a blast control method based on wavelet analysis. [PERSON] [22] optimized a trenching and blasting plan for the Kaiyuan Temple Tunnel in conjunction with on-site monitoring to reduce the vibration hazards of blasting. [PERSON] [23] analyzed the methodology through numerical modeling and field monitoring, obtaining the maximum charge for the blasting construction of the Chongli Tunnel going down through the village to ensure the stability of the village. In most scholarly studies, the problem of full-section blasting has been dealt with for specific projects, including the control of blasting vibration by means of simulation and monitoring, as mentioned above, and scholars have contributed a lot to infrastructure work. However, the problems encountered vary from project to project.