Establishment and Application of the Spatial Decomposition Method (SDM) for Tunnels Passing Through Large Karst Caves

Abstract

Karst tunnels commonly pass through large karst caves during their construction and operation. Although treatment technologies are relatively mature, a systematic treatment method to guide the selection of treatment technologies is lacking. To solve this problem, a spatial decomposition method (SDM) of large karst caves is proposed that is based on analyzing the spatial relationship between tunnels and karst caves and summarizing the relevant treatment techniques. In this method, the space between the tunnel and the cavern is divided into eight parts using a space dividing line (SDL), which makes the spatial position relationship between the tunnel and cavern more intuitive. A geometric model of the SDM is established, and the numerical values of each geometric parameter are determined by field surveys and drawings. Constructing a three-dimensional spatial diagram by applying relevant parameters to the geometric model provides a reference for selecting a treatment technology. The SDM of the arch top, arch bottom, and two wings matching the treatment technology is proposed. Seven principles of technical selection—namely, safety, convenience, scientificity, sustainability, economy, feasibility, and openness—are mentioned in order to overcome the difficulty of technology selection due to such factors as technological diversity, materials, equipment, and environment. Finally, the SDM is used to solve the problem of the Shangyuan tunnel passing through a large karst cave. The implementation of the SDM in tunnel construction would represent a significant breakthrough and has important engineering value in solving the problem of tunnel passes through large karst caves.

Study on safe crossing in the dry season and an anti-floating drainage scheme in the wet season: a case study in Guiyang, Southwest China

“…Based on the spatial relationship between tunnels and caves, Shi et al summarised relevant treatment techniques and proposed a spatial decomposition method for large caves. This method can provide a reference for selecting the treatment technology 32 . Wang used the giant karst cave of Qianchang Railway’s high mountain tunnel as a research object.…”

Study on reinforcement crossing in dry season and anti-floating scheme of drainage in wet season：A case study in Guiyang, southwest China

“…According to the distribution of water outlet and water source, the detection area is divided into three sections and curtain grouting is carried out [29]. In order to solve the problem of lack of systematic treatment methods to guide treatment technology during construction and operation of karst tunnels, Zhenyue Shi et al proposed a large-scale karst cave space decomposition method (SDM), which can provide reference for the selection of treatment technology [30]. Wentao Tao takes geological condition data of karst area in Wuhan and design of some subway tunnels as examples to analyze potential problems in karst area and discuss in detail the solution proposed for this subway tunnel project [31].…”

Sensitivity Analysis of Influencing Factors of Karst Tunnel Construction Based on Orthogonal Tests and a Random Forest Algorithm

“…Therefore, it is relatively typical to encounter karst caves or soil holes during the tunnel-construction process. For zones with strong karst development, the geological conditions are complicated, which could easily lead to geological disasters [2] such as water-mud inrush [3], karst collapse [4], perilous rock collapse [5], and other geological disasters [6]. In the procedure of studying the response of mechanical characteristics in tunnel construction in karst areas [7], it is fundamental to determine the sensitivity of the influencing factors involved.…”