Consolidation and Deformation Characteristics of Soft Rock Foundation in Hydrological Wetland Environment

Bin Liu,Xiugen Jiang

doi:10.15446/esrj.v24n2.87920

Abstract

The widespread distribution of soft rock and soft soil in hydrological wetland environment is a common geotechnical engineering problem encountered in coastal engineering construction. To solve this problem, a study method for consolidation and deformation characteristics of soft rock and soft soil foundation in hydrological wetland environment is proposed. Taking K9+280-K11+120 section along Fu-Nehe section of National Highway 111 as the research object, the consolidation and deformation characteristics and loading conditions of soft soil foundation under embankment filling load, treatment methods of soft rock foundation, stratum conditions, temperature changes and time effects are analyzed. The results show that although the wetland soft rock and soil layer is not thick, the settlement of soft rock and soil accounts for more than 80% of the total settlement. Negative temperature has a certain influence on the consolidation settlement of soft rock foundation, which is mainly manifested in the difference between the settlement process of the central separation zone and the roadbed soft soil foundation; the pore water pressure of soft rock foundation dissipates to varying degrees. According to the monitoring results of settlement and pore water pressure, bagged sand wells are more suitable for soft rock foundation engineering treatment in hydrological wetland. The research results can provide a reference for the study, calculation and design of consolidation and deformation of soft rock foundation in hydrological wetland.

Highlights

The shrinkage of soil under pressure is called the compressibility of soil (Baral et al, 2018)
In the hydrological wetland area, in order to carry out the construction of soft rock foundation smoothly, cofferdams are built on both sides of most sections before foundation treatment, and counter-pressure barriers are built between cofferdams and roads
The engineering geological problems faced by the construction of highgrade highway on soft rock foundation are mainly the settlement and stability of soft rock foundation

Summary

Introduction

The shrinkage of soil under pressure is called the compressibility of soil (Baral et al, 2018). The process of soil compression increasing with time and dissipation of excess pore water pressure is called consolidation of soil, which is generally divided into primary consolidation and secondary consolidation (Huang et al, 2017). Consolidation and deformation characteristics of soft rock foundation in hydrological wetland environment are affected by many factors, such as physical and mechanical properties of soft rock and soil, sludge thickness of hydrological wetland, loading capacity, loading mode and field environment (Xu et al, 2017; Kotani et al, 2017). In the hydrological wetland area, in order to carry out the construction of soft rock foundation smoothly, cofferdams are built on both sides of most sections before foundation treatment, and counter-pressure barriers are built between cofferdams and roads. The parameters of soil layer, initial conditions and boundary conditions of field prototype tests are difficult to adjust, and the influence of each factor on the deformation characteristics cannot be accurately analyzed

Methods

Findings

Discussion

Conclusion