Experimental Study on Stress and Strain Characteristics of Solidified Clay under Seawater Condition

This paper presents the results of a laboratory study on the stress-strain relationship of solidified clay formed in seawater corrosion condition. An automatic triaxial apparatus was used and the axial stress and strain was monitored continuously. The dry density was 1.0g/cm3, the cement contents were 4, 6, 8 and 10% by weight of dry soil particles, and the curing time was 28, 60 and 90 days respectively. Test results indicate that the stress strain relationship of cemented clay was affected by soil density, cement content and curing period. A behaviour of strain hardening to strain softening occurred with the increase of cement content. Strong structure will form in cemented clay when the admixture content is 10% or more. The increase in strength of the solidified foundation is resulted from the increase in internal friction angle and cohesive force. The cohesive force increases obviously with the increase of the cement content and the curing age, but the change of internal friction angle is not pronounced after reaching a certain value

Numerical Simulation of Hydraulic Fracturing in Earth and Rockfill Dam Using Extended Finite Element Method

Hydraulic fracturing is one of the most important factors affecting the safety of earth and rockfill dam. In this paper, the extended finite element method (XFEM) is used to simulate the hydraulic fracturing behavior in an actual high earth and rockfill dam. The possibility of hydraulic fracturing occurrence is analyzed, and the critical crack length is obtained when hydraulic fracturing occurs. Then, the crack propagation path and length is obtained by inserting initial crack of different lengths at different elevation. The results indicate that hydraulic fracturing will not occur without the permeable weak surface (initial crack). The critical initial crack length required for hydraulic fracturing is 5.3 m of the calculation model in this paper. The propagation length decreases with the increase of elevation, and the average propagation length decreases from 9.4 m to 3.4 m. Furthermore, it is proved that the direction of crack propagation has a certain angle with the horizontal plane toward the downstream. Considering the up-narrow and down-wide type of the core wall, the possibility of hydraulic fracturing to penetrate the core is extremely high when the upper part of the core wall reaches the critical crack length

Experimental Study on Stress and Strain Characteristics of Solidified Clay under Seawater Condition

This paper presents the results of a laboratory study on the stress-strain relationship of solidified clay formed in seawater corrosion condition. An automatic triaxial apparatus was used and the axial stress and strain was monitored continuously. The dry density was 1.0g/cm3, the cement contents were 4, 6, 8 and 10% by weight of dry soil particles, and the curing time was 28, 60 and 90 days respectively. Test results indicate that the stress strain relationship of cemented clay was affected by soil density, cement content and curing period. A behaviour of strain hardening to strain softening occurred with the increase of cement content. Strong structure will form in cemented clay when the admixture content is 10% or more. The increase in strength of the solidified foundation is resulted from the increase in internal friction angle and cohesive force. The cohesive force increases obviously with the increase of the cement content and the curing age, but the change of internal friction angle is not pronounced after reaching a certain value