Study On Liquefaction Resistant Of Silty Sand In Nansha,Guangzhou

Nansha,Guangzhou is a state key cooperation demonstration zone between Guangdong,Hong Kong and Macao during the construction of Guangdong-Hong Kong-Macao Greater Bay Area.With the development of Nansha,this land will bear a great deal of engineering constructions.There are much silty sand in Nansha which signifies that a large portion of housing constructions and transportation infrastructures will be construced in the silty sand foundation.It is vey dangerous if sand liquefaction happens at this area.Therefore,studying of liquefaction-resistant characteristics of silty sand in Nansha,Guangzhouis is of great practical significance for the development of the key cooperation demonstration zone between Guangdong,Hong Kong and Macao.In order to explore the liquefaction-resistant characteristics of silty sand in Nansha,Guangzhou,the author studies the influence of three main factors on the liquefaction-resistant characteristics of silty sand by separately changing the silt content,consolidation confining pressure and relative density of samples under the condition of keeping other test conditions stay the same.Finally,combining the quantitative relationship between the three factors and the anti-liquefaction strength of silty sand soil,a liquefaction resistance formula of silty sand in Nansha,Guangzhou is obtained by numerical fitting.The main conclusions and results are as follows.(1)The influences of silt content on the liquefaction resistance of silty sands are as follows.?when silt content is low,the growth law of axial dynamic strain is that it grows fast in the early stage,slows in the middle stage and rises fleetly in the final stage,the whole process is uniform.;With the increase of silt content,the growth of axial dynamic strain is accelerated in the early stage and decreased in the later stage,and the process of speed rebound will no longer appear.?With the increase of silt content,the anti-liquefaction strength of silt sandy decreases and then rises,the anti-liquefaction performance of silt sandy is the worst when silt content is about 18%.?when silt content is low,the growth law of pore water pressure is that it grows fast in the early stage,slows in the later stage and rises fleetly in the final stage.?With the increase of silt content,pore water pressure is less likely to increase.(2)The influences of confining pressure on the liquefaction resistance of silty sands are as follows.?with the increase of confining pressure,the anti-liquefaction strength of silty sand increases,and the relationship between the strength and confining pressure is obviously proportional.?with the increase of confining pressure,hole pressure ratio of the sample decreases,therefore,the increase of confining pressure is unfavorable to the increase of pore pressure of silty sand.(3)The influences of relative density on the liquefaction resistance of silty sands are as follows.?with the increase of relative density,the anti-liquefaction strength of silty sand increases.?with the increase of relative density,hole pressure ratio of the sample decreases,therefore,the increase of relative density is unfavorable to the increase of pore pressure of silty sand.(4)It is assumed that silt content,confining pressure and relative density independently affect the liquefaction resistance,a liquefaction resistance formula of silty sand in Nansha,Guangzhou is obtained by numerical fitting as following:?d =-15EXP[-0.0625(PC-18)2]-0.07Nf+0.8?3 +30Dr-5...