# Low Carbon Optimization of Deep Foundation Pit Support in Undulating Strata
## 1 Introduction  
The advancement of urban development offers a favorable prospect for the investigation of deep foundation excavation support engineering. There are many problems in deep foundation pit support engineering in China, such as complex geological conditions and fluctuating strata. The existing foundation excavation support design approach is excessively cautious and fails to guarantee construction safety, leading to significant resource and material waste. Therefore, it is the only way for low-carbon geotechnical engineering to adopt reasonable methods to make the design of foundation pit support more refined. At present, there are three design methods for foundation pit support. [PERSON] et al. [1] used the limit balance method to analyze the failure mode of the single-row supported foundation pit and the influence of engineering piles in the pit on the stability of the foundation pit. [PERSON] et al. [2] used the limit analysis method to study the stability of the foundation pit. [PERSON] [3] analyzed the design with the equivalent beam method of single fulcrum row piles in a deep foundation pit retaining structure. [PERSON] et al. [4] proposed a vertical elastic foundation beam model to solve the problem of nonlinear correlation between earth pressure and support structure deformation in the design of deep foundation pit support structures. [PERSON] et al. [5] used an elastic foundation beam model to study the force of the support structure. With conventional design methods, the internal force can generally only be calculated, and it is difficult to calculate the deformation of the supporting structure. The third method is the finite element method, which is considered to be the most promising calculation method. Based on the foundation pit support design scheme, [PERSON] [6] used the three-dimensional finite element dynamic process numerical simulation to study the impact of foundation pit excavation on the surrounding existing structures. [PERSON] et al. [7] established finite element analysis models to study the deformation of foundation pits. [PERSON] et al. [8] used the numerical simulationmethod to study the influence of the distance between the foundation pit and tunnel and the width and depth of foundation pit excavation on the stress of the tunnel bolt. [PERSON] et al. [9] used FLAC\({}^{\text{3D}}\) 6.0, a three-dimensional finite-difference software simulation, to study the variation law of formation stress. Ample researchers have carried out research around the optimization of foundation pit engineering and proposed many optimization design methods, such as modern engineering mathematical methods [10], inverse analysis methods [11], and computer-aided design methods [12], Monte-Carlo stochastic simulation methods [13], numerical calculation methods [14], hybrid neural network methods [15], support vector machine approaches [16], projection pursuit methods [17], and system engineering optimization design methods [18]. In order to determine the relationship between influencing factors and the best bid plan, [PERSON], [PERSON] [19] developed an evaluation model for deep foundation pit support schemes based on UM. Most studies use only a single approach, and the optimization effect is not obvious. Furthermore, [PERSON] et al. [20] used an optimized MSD method to predict foundation pit deformation under specific formation conditions. [PERSON] et al. [21] studied the internal process control of deep foundation pit engineering and the coordination of internal and environmental systems. According to the rule of the genetic algorithm, [PERSON] [22] designed the optimization design system of the pile anchor supporting structure in a deep foundation pit. These studies provide important guidance for the practical engineering application of foundation pit support.