Different criteria and factors are used in different methods of soft soil foundation settlement calculation and engineering geological zoning.The methods used are not universally suitable for complex geological enviro...Different criteria and factors are used in different methods of soft soil foundation settlement calculation and engineering geological zoning.The methods used are not universally suitable for complex geological environments.The post-construction settlement of soft soil foundations are especially large and difficult to calculate.In addition,there are many deficiencies in the current methods used for engineering geological zoning.Focusing on the need of establishing engineering geological zoning for areas with soft soil foundations in the Tianjin Marine Economic Area,combination weighting and extension methods were introduced.An evaluation model for the settlement of soft soil foundations was established using multiple factors and large amounts of data.This evaluation model is accurate and objective for delineating engineering geological zoning.These methods eliminate deficiencies by considering both objective and subjective factors,and help obtain an objective and accurate result.展开更多
The scientific field test site of rainfall-soil moisture-groundwater conversion in Dabie Mountain Area–Jianghan Plain is located in the northern region of the Jianghan Plain,the transition zone between the Dabie Moun...The scientific field test site of rainfall-soil moisture-groundwater conversion in Dabie Mountain Area–Jianghan Plain is located in the northern region of the Jianghan Plain,the transition zone between the Dabie Mountain Area and Jianghan Plain.It’s a great field test site to study the material and energy exchange among rainfall,soil moisture,and groundwater of the Earth’s critical zone in subtropical monsoon climate plain areas.This paper analyzed the connection between rainfall and volume water content(VWC)of soil at different depths of several soil profiles,and the dynamic feature of groundwater was discussed,which reveals the rainfall infiltration recharge of Quaternary Upper Pleistocene strata.The results show that the Quaternary Upper Pleistocene aquifer groundwater accepts a little direct rainfall recharge,while the lateral recharge is the main supplement source.There were 75 effective rainfall events among 120 rainfall events during the monitoring period,with an accumulated amount of 672.9 mm,and the percentages of effective rainfall amount and duration time were 62.50%and 91.56%,respectively.The max evaporation depth at the upper part in Quaternary cohesive soil was no less than 1.4 m.The soil profile was divided into four zones:(1)The sensitive zone of rainfall infiltration within 1.4 m,where the material and energy exchange frequently near the interface between atmosphere and soil;(2)the buffer zone of rainfall infiltration between 1.4 m and 3.5 m;(3)the migration zone of rainfall infiltration between 3.5 m and 5.0 m;and(4)the rainfall infiltration and groundwater level co-influenced zone below 5.0 m.The results revealed the reaction of soil moisture and groundwater to rainfall in the area covered by cohesive soil under humid climate in Earth’s critical zone,which is of great theoretical and practical significance for groundwater resources evaluation and development,groundwater environmental protection,ecological environmental improvement,drought disaster prevention,and flood disaster prevention in subtropical monsoon climate plain areas.展开更多
In coordination of the construction of concealed work of levee project, the research on the soil quality of Jingnan levee in Hubei province was carried out through test. The results demonstrate: ① the Jingnan levee e...In coordination of the construction of concealed work of levee project, the research on the soil quality of Jingnan levee in Hubei province was carried out through test. The results demonstrate: ① the Jingnan levee embankment is in bad quality, the compaction degree of most levee sections doesn’t reach 92%; the average compressive coefficient of the levee backfilled soils is about 0.3 MPa; the seepage coefficients are 10\+ -5 ～10\+ -6 cm/s generally; the levee body was compacted unevenly; ② the soil layers of the levee foundation are distributed complicatedly and generally in low density; the void ratios of various soils are mostly in 0.7～1, indicating that the foundation soils are generally in loose state; ③ the pH value of levee body and foundation is 7.05～8.95, attributing to weak alkaline and not producing significant influence on liquid-plastic limit and shear strength of soils, the content of strongly soluble salt of levee foundation soils is 0.01%～0.52% and will not produce great influence on the mechanical behaviours of soils.展开更多
基金National Natural Science Foundations of China(Nos.41172236,41402243)
文摘Different criteria and factors are used in different methods of soft soil foundation settlement calculation and engineering geological zoning.The methods used are not universally suitable for complex geological environments.The post-construction settlement of soft soil foundations are especially large and difficult to calculate.In addition,there are many deficiencies in the current methods used for engineering geological zoning.Focusing on the need of establishing engineering geological zoning for areas with soft soil foundations in the Tianjin Marine Economic Area,combination weighting and extension methods were introduced.An evaluation model for the settlement of soft soil foundations was established using multiple factors and large amounts of data.This evaluation model is accurate and objective for delineating engineering geological zoning.These methods eliminate deficiencies by considering both objective and subjective factors,and help obtain an objective and accurate result.
基金the project“1:50000 regional hydrogeological survey in the Dabie Mountains contiguous destitute area”(121201009000172522)from Wuhan Center of Geological Survey,China Geological Survey(CGS).
文摘The scientific field test site of rainfall-soil moisture-groundwater conversion in Dabie Mountain Area–Jianghan Plain is located in the northern region of the Jianghan Plain,the transition zone between the Dabie Mountain Area and Jianghan Plain.It’s a great field test site to study the material and energy exchange among rainfall,soil moisture,and groundwater of the Earth’s critical zone in subtropical monsoon climate plain areas.This paper analyzed the connection between rainfall and volume water content(VWC)of soil at different depths of several soil profiles,and the dynamic feature of groundwater was discussed,which reveals the rainfall infiltration recharge of Quaternary Upper Pleistocene strata.The results show that the Quaternary Upper Pleistocene aquifer groundwater accepts a little direct rainfall recharge,while the lateral recharge is the main supplement source.There were 75 effective rainfall events among 120 rainfall events during the monitoring period,with an accumulated amount of 672.9 mm,and the percentages of effective rainfall amount and duration time were 62.50%and 91.56%,respectively.The max evaporation depth at the upper part in Quaternary cohesive soil was no less than 1.4 m.The soil profile was divided into four zones:(1)The sensitive zone of rainfall infiltration within 1.4 m,where the material and energy exchange frequently near the interface between atmosphere and soil;(2)the buffer zone of rainfall infiltration between 1.4 m and 3.5 m;(3)the migration zone of rainfall infiltration between 3.5 m and 5.0 m;and(4)the rainfall infiltration and groundwater level co-influenced zone below 5.0 m.The results revealed the reaction of soil moisture and groundwater to rainfall in the area covered by cohesive soil under humid climate in Earth’s critical zone,which is of great theoretical and practical significance for groundwater resources evaluation and development,groundwater environmental protection,ecological environmental improvement,drought disaster prevention,and flood disaster prevention in subtropical monsoon climate plain areas.
文摘In coordination of the construction of concealed work of levee project, the research on the soil quality of Jingnan levee in Hubei province was carried out through test. The results demonstrate: ① the Jingnan levee embankment is in bad quality, the compaction degree of most levee sections doesn’t reach 92%; the average compressive coefficient of the levee backfilled soils is about 0.3 MPa; the seepage coefficients are 10\+ -5 ～10\+ -6 cm/s generally; the levee body was compacted unevenly; ② the soil layers of the levee foundation are distributed complicatedly and generally in low density; the void ratios of various soils are mostly in 0.7～1, indicating that the foundation soils are generally in loose state; ③ the pH value of levee body and foundation is 7.05～8.95, attributing to weak alkaline and not producing significant influence on liquid-plastic limit and shear strength of soils, the content of strongly soluble salt of levee foundation soils is 0.01%～0.52% and will not produce great influence on the mechanical behaviours of soils.
