*Article* **Improved Double-Layer Soil Consolidation Theory and Its Application in Marine Soft Soil Engineering**

**Deqiang Chen <sup>1</sup> , Junhui Luo 2,\*, Xianlin Liu <sup>2</sup> , Decai Mi <sup>2</sup> and Longwang Xu <sup>2</sup>**


Received: 4 April 2019; Accepted: 16 May 2019; Published: 18 May 2019

**Abstract:** Marine soft soil foundation is a double-layer foundation structure with a crust layer and soft substratum. Moreover, it is common that there are various forms of drainage. Accordingly, based on Terzaghi's consolidation theory and the continuous drainage boundary conditions theory of controllable drainage conditions, an improved double-layer soil consolidation theory considering continuous drainage boundary conditions was proposed. To improve the computational efficiency and accuracy, the Laplace transform and the Stehfest algorithm was used to deduce the numerical solution of the improved double-layer soil consolidation theory considering continuous drainage boundary conditions and to compile a computer program. Subsequently, the theory was validated and analyzed by the degenerated model of the perfectly permeable boundary conditions and the semi-permeable boundary conditions, respectively, which showed that this theory has higher accuracy. Simultaneously, the analysis of double-layer consolidation settlement under continuous drainage boundary conditions for marine soft soil foundation of Guangxi Binhai Highway was carried on. The result showed that the consolidation settlement calculated by the improved double-layer consolidation theory presented is basically consistent with the field measurement results, and that the correlation coefficient between them is higher. Accordingly, the research results can provide useful basic information for marine soft foundation engineering.

**Keywords:** marine soft soil; double-layer foundation; consolidation theory; drainage boundary
