The Infiltration And Reinforcement Effects Of SH Solution On The Site Soil

Earthen sites are destroyed seriously in northwest of China,because of the severe natural environment.Weathering is one of the main reasons for destruction of earthen sites and causes large losses of economy and culture.Therefore,studying of anti-weathering is of great practical significance.The development of anti-weathering relies on study of new materials.SH solution is a new polymer material,which is studied by Lanzhou university.It has been verified that SH can meet requirements of the reinforcement materials for earthen sites.Drilling grouting and surface spraying are normal techniques of anti-weathering for earthen sites.In this paper,drilling grouting is studied mainly and surface spraying is described briefly for fine-grained soil and coarse-grained soil.Firstly,effective reinforcement region of SH is determined by hardness,control experiment and scanning electron microscope(SEM).Then,the change laws of reinforcement radius,infiltration rate,infiltration time and hardness are discussed for fine-grained soil under different pore diameters and different dry densities.Effects of infiltration and reinforcement are studied for coarse-grained soil under different dry densities and different gradations at the moment.At last,a control indicator is presented for fine-grained soil and coarse-grained soil,and it’s illustrated by instances.The experimental results are analyzed above and 3 main results are obtained:(1)When dry density of fine-grained soil is less than 1.50g/cm~3,it has a large effect on effective reinforcement radius,infiltration rate,infiltration time and hardness.The effect of drilling grouting is better.Therefore,when earthen sites are reinforced for the fine-grained soil by SH infiltration,the void ratio e>0.779 is suggested.It’s also found that grouting volume has a greatest effect on reinforcement radius,mean Feret diameter follows and pore diameter is the last.The critical dry density of coarse-grained soil is 1.90g/cm~3.Therefore,when earthen sites are reinforced for the coarse-grained soil by SH infiltration,the void ratio e>0.406,the uniformity coefficient C_u>91 and the coefficient of gradation C_c<0.30 of the soil need to be met simultaneously.(2)The soil reinforced with SH can improve resistance of collapse,dry-wet cycle and freeze-thaw cycle.Migration of soluble salt can be inhibited by adding SH.(3)Because of the dual-porosity structure,the coarse-grained soil has a large difference with fine-grained soil for SH infiltration.Although infiltration and reinforcement effects of the coarse-grained soil is better than the fine-grained soil,uniformity of the coarse-grained soil is less than the fine-grained soil.It’s suggested that combine advantages of surface spraying and drilling grouting to reinforce coarse and fine grained soils for anti-weathering.