| With the continuous advance of reform and opening-up, the real estate industry plays an increasingly important role in the market economy, and has attracted wide attention from the society. Especially in recent years,with the accelerating pace of city construction, more and more high-rise buildings have been built, the new buildings were also built in the old city. The vigorous development of the construction industry has also led to advances in related fields of engineering technology, such as ground surveying, the foundation pit engineering, underground engineering, foundation treatment and so on. Take more time to researching on the strata spatial uncertainty factors and uncertainty factors are the basic way,which can ensure the smooth progress of construction projects. In the rich southeast coastal areas of our country, the formation of soil spatial distribution pattern is an important factor,which restricting land planning and construction. At the same time, the regional environment also affects the land using and economical development. From the regional scale, we should understand these factors with systematic and scientific attitude,which were on the study area plots about the mainland rock and soil parameter space distribution characteristics and influence. It is a powerful guarantee of engineering construction. It also has an important guiding significance for regional macro decision.This paper takes a typical coastal sedimentary strata as the study area.The overall situation is mainly to find out the variation of formation parameters at the present stage. At the same time,it wants to clarify the spatial variability and spatial distribution pattern, and to reveal the relationship between soil factors and environmental parameters under different scales. The parameters of rock and soil is from Funing County of Jiangsu Province, "Xiangyang garden 1# ~ 22# floor exploration report". The main research stratas have three layers,which were the third layer of muddy silty clay, the eighth layer of silty clay,the ninth layer of clay. there are 43 exploration holes in the third layer or the eighth layer; The ninth clay layer has 29 exploration holes. Through classical statistics(overall variation, variance analysis, mean comparison), geostatistics(semi variogram, Kriging interpolation) and the state space simulation method, it analyzed the main influence factors of spatial variability, stratum parameters, spatial interpolation and prediction under different spatial scales. The main results are as follows:(1) In the overall,the geotechnical parameters’ variation is at a medium weak level in this area. Geostatistical analysis showed that, the muddy silty clay layer of rock and soil parameters’ variations are in the medium level,such as liquid limit, plastic limit, liquid index. Their coefficient of nugget is less than 0.25. The silty clay layer parameters exhibited moderate variation, like void ratio, compression modulus.Their coefficient of nugget are from 0.25 to 0.75. Compression modulus, the clay parameter exhibited moderate variation w. All of the directions, its nugget coefficients are between 0.25 and 0.75. Comparison of semivariogram analysis, the main parameters of rock and soil stratum are without obvious anisotropy in regional survey scale.(2) This paper studies the spatial correlation of geotechnical parameters. The results as follows:in the muddy clay layer, water content and void ratio had a strong positive correlation, the correlation coefficient is 0.9410. There is a strong negative correlation between the compression coefficient and compression modulus in this layer, the correlation coefficient is-0.9450. moisture content, void ratio, liquid index and compression coefficient the index has a good spatial co correlation in different directions, X direction range all close to 5.7 meters, Y direction range all close to 7.1 meters. Water content and void ratio are better autocorrelation, the global change range is 7 meters.In the silty clay layer, water content, void ratio and liquid index are in a strong positive correlation, the correlation coefficient is larger than 0.73. The compression coefficient and compression modulus are in a negative correlation, the negative correlation coefficient is-0.9527. Water content,liquid index and compression’s spatial associations are with better correlation in different directions,their mutual co correlation range values are close to 5 meters. There is a strong spatial autocorrelation between liquid limit, plastic limit and compression modulus, the global variable range value can be set to 7 meters.In the clay layer, there is a strong positive correlation ratio between water content,liquid limit and plastic limit; there is a strong correlation between the liquid limit, plastic limit and plastic index.The parameters of soil water content,void ratio, liquid limit, plastic index and liquid index, have a better spacial coordination in different directions, the co-correlation range value can be determined for 5.5 meters; water content, liquid limit, plastic limit, plasticity index and liquidity index have a strong spatial autocorrelation, the global variable range value can be set to 6 meters.(3) According to the researching on the formation parameters and the optimal scale selections, these datas are not comparable under different scales. Water content, liquid index and compression coefficient are on the response of different scale space about spatial variation. The optimal scale of moisture content and compression coefficient for 8m is appropriate, the liquidity index should be set to 10 m.(4) Researching on the study area stratum, this paper expounds the application of geostatistics in the design, survey and construction. The analysis shows that, the muddy soil layer’s liquid limit, plastic limit, liquid index are in a high variability level. They are should be done more survey. Researching on spatial variability of different directions, muddy soil layer in the Y direction is more spatial variability. So the Y direction should be on the focus of investigation. Through Kriging spatial interpolation, the paper drown out the main formation compression-coefficient’s spatial distribution. It has some practical significance for guiding the design and construction.(5) On the regional scale, natural factors, such as precipitation, clear pond, dark pond, river distribution and soil composition, have a significant impact on the formation of geotechnical parameters; human factors, such as surveying error, test method, have some relationship between the natural factors, and significantly affecting the geotechnical parameters. Overall, the soil stratum parameters is stable distribution, only a little medium weak spatial variability.This paper is based on the field test data. It understands these relationships about littoral facies sedimentary pore formation ratio,which are between the soil water content, liquid limit, liquid index, plastic limit, plasticity index and the compression coefficient on the spatial variation of compression modulus and the relationships with environmental factors from the overall. The reliable formation parameters of spatial datas abundant the littoral facies area database. It provides the overall framework that guiding development about the soil parameters of spatial variability and in-depth research. It provides reliable datas which supporting the future of the region on a large scale digital soil mapping, sedimentary simulation, geological environment evaluation.The related researching results can also been using to guide the macro decision and the practice on the construction of the studying region. |
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