Theoretical Solutions to The Problem of Seepage and Consolidation in Saturated Clay Based on The Spatial Axisymmetric Model

The series solutions to the problem of spatial axisymmetric consolidation are deduced under non-homogeneous boundary conditions. Firstly, differentiable step function is introduced to construct the homogeneous operation function. Secondly, the operation function is used to superimpose the non-homogeneous boundaries to obtain homogeneous boundaries, non-homogeneous fundamental equation and new initial condition. Finally, the method of variables separation is used to construct the eigenfunction, and due to the mathematical justification of complete orthogonality of the eigenfunction, the series expansions of the fundamental equation and initial condition are carried out to obtain solutions for the seepage and consolidation in saturated clay with a borehole boundary. The correctness of the theoretical solutions are verified by the strict mathematical and mechanics derivation and the law of space-time variation in seepage flow.

Soil bases modified with lime waste and polycarboxylates

Increasing the volume of road construction is one of the priority areas of infrastructure development in any country. When building roads, it is preferable to use local materials to reduce the cost of their transportation, therefore, it is advisable to build the roadbed on local soils. It is worth noting that clay water-saturated soils are the most common, which complicates the construction of the road due to some features of this type of soil. The object of the study is a water-saturated clay with the following characteristics: natural humidity from 25.3 % to 28.1% by weight, optimal humidity from 11.8 % to 16.7% by weight, the number of plasticity from 0.118 to 0.153. Clay soils have a number of features: waterlogged soils are difficult to compact and develop, it is quite problematic to dry them, and thixotropy is also characteristic of clay soils. In this regard, it is most advisable to use the method of complex mineral binders to optimize their physical and mechanical properties. In the course of laboratory studies, compositions of soil compositions with the addition of lime waste and superplasticizer P-17 were developed. The dependence of the strength on the consumption of mineral binders and surfactants is established: the maximum compressive strength of the soil being fixed is achieved at a lime content of 25 wt.% and at a P-17 content in the range of 0.10-0.5 wt.%.