Test And Analysis On Infiltration Characteristics And Subgrade Bearing Capacity Of Collapsible Loess

Loess are extensively distributed throughout the world, especially in our country, the distribution area of loess account for about 5% of the world’s total area. Loess itself has special engineering geological characteristics, accordingly the extensive distribution of loess in China has brought many problems that need to be solved urgently. Reach about the engineering geological characteristics of the loess can help people to raise awareness and understanding about the change rule of loess which in different region, environment, and working conditions, ultimately provide strong scientific and technical guarantee for carrying out the engineering construction in the loess distribution area. The engineering geological properties of loess usually perform differences, which has direct relationship with the different geological formation era. Old loess is formed in the earlier geological time, which includes Q1 WuCheng loess and Q2 LiShi loess. Old loess experienced a long geological period of overlying strata pressure, so it has relatively stable mechanical properties. At the same time, the old loess has deeper distribution location and smaller distribution area, so its effect on human engineering activity is much less than the Q3 loess and Q4 loess. Considering engineering construction, the research of loess is mainly concentrated to the Q3 loess and the Q4 loess, the main contents includes the collapsibility of loess, permeability, microstructure and mechanical properties, etc.This paper takes aeolian Q3 loess as the research object,which is located in Lanzhou south march circle west orchard interchange, through double loop water injection test, trial pit water immersion test, high density resistivity test etc, and along with the routine test studied of moisture migration rule when collapsible loess immersed. The research acquired permeability coefficient of saturated and un saturated infiltration of collapsible loess, the morphological changes of infiltration section and the change regularity of permeability coefficient in horizontal direction and vertical direction in the process of infiltration. By observing the sedimentation in the process of flooding infiltration in test pit,we can get the different stages subsidence regularity of the collapsible loess saturation in flooding process, than coMParatively analyzed to flood infiltration law of collapsible loess, eventually illustrated the close relationship between them.Use shallow plate load test, static cone penetration test and standard penetration test to obtain the foundation bearing capacity under natural and saturated unsaturated state of collapsible loess stems from Lanzhou south march circle west orchard interchange. CoMPared and analyzed large number of bearing capacity empirical formulas can help us get the foundation bearing capacity related empirical formulas of static sounding indexes, standard penetration indexes and physical property indexes of collapsible loess, as well as help to obtain the result of physical and mechanical properties and foundation bearing capacity of collapsible loess after flooding.