紫色母岩成土的物理作用机制

CORC > 成都山地灾害与环境研究所 > 中国科学院水利部成都山地灾害与环境研究所 > 山地灾害与地表过程重点实验室

题名	紫色母岩成土的物理作用机制
作者	张丹
学位类别	博士
答辩日期	2012-05-18
授予单位	中国科学院研究生院
授予地点	北京
导师	刘刚才
其他题名	Physical Mechanism of Soil Formation in Purle
学位专业	自然地理学
中文摘要	为了分析紫色母岩成土的物理作用机制，以白垩系红层马头山组（K2m）、侏罗系红层中的妥甸组（J3t）和侏罗系红层下禄丰组（J1l）为研究对象，通过室内外试验测定三种紫色母岩成土速率及其影响因素的各项指标，分析了三种母岩理化特性、温度、水分、水热综合作用与母岩成土过程的相互作用规律，从物理机制方面建立这三种母岩的成土定量估算模型，并对模型进行了验证。主要研究结果如下：（1）三组母岩的密度、吸水率和饱水系数为妥甸组>禄丰组>马头山组。禄丰组风干处理和饱和处理的抗压强度最大，其次是马头山组和妥甸组。三种泥岩颗粒分维数大小依次为禄丰组﹥马头山组﹥妥甸组，而孔隙分维数大小为妥甸组﹥禄丰组﹥马头山组。马头山组、妥甸组和禄丰组黏土矿物分布占矿物含量的40%、60%和48%。禄丰组的SiO2和Fe2O3含量高于马头山组和妥甸组；妥甸组和马头山组的Al2O3含量大于禄丰组。（2）不同水热处理下，三种母岩的崩解形态分为溃散或分离式崩解、剥落式崩解和难崩解。不同处理下三种母岩崩解过程的崩解质量分维数大小为饱和极端温差处理>饱和自然温差处理>浸水极端温差处理>浸水自然温差处理>极端冷热处理。相同处理下三种母岩崩解过程的分维数大小为妥甸组>马头山组>禄丰组。（3）三种母岩的成土速率随着恒温的增加呈幂函数增加，随温差的增加呈指数函数增长。在相同恒温和温差条件下，三种母岩的成土速率为妥甸组>马头山组>禄丰组。随温差的变化，3种母岩的成土速率在冻融处理下最高，其次是大温差处理，最小为自然温差处理。在-5 ～40℃处理下，冻融作用引起的妥甸组、马头山组和禄丰组的成土速率分别占总成土速率的56.3%、48.4%和33.3%。根据恒温和温差变化对成土速率的相关关系，建立了温度与成土速率的回归方程。（4）三种母岩的成土速率随含水量的增多呈上升趋势，且成土速率与不同含水量呈指数函数关系。在含水量较低时，三种母岩的成土速率相差不大，随着含水量的逐渐增加，妥甸组母岩的成土速率增长速度明显快于马头山组和禄丰组。在相同水分条件下成土速率为妥甸组>马头山组>禄丰组。根据含水率变化对成土速率的相关关系，建立了水分与含水率的回归方程。（5）为了定量分析温度和水分综合因素对成土速率的影响，根据以上对单个因子与成土速率关系的分析，建立水热综合因素下的成土速率模型。同时对所有处理下成土速率进行计算，求出各种处理下的相对误差，并对三种母岩在不同处理下的相对误差进行平均，发现三种母岩成土速率的计算值与实测值差异不大，妥甸组、马头山组和禄丰组的平均相对误差分别为9.6%、11.6%和13.2%，说明用该回归方程能较为准确地计算不同水热条件下三种母岩的成土速率。（6）野外试验中妥甸组母岩的成土速率要高于马头山组和禄丰组。露天处理下母岩的成土速率明显大于盖瓦处理，说明母岩在降雨的浸润下，母岩内部的黏土矿物吸水后发生膨胀，之后又在元谋干热的气候作用下迅速失水收缩，同时加之昼夜、季节温差和空气湿度变化的存在，极大的促进了母岩的崩解。在不同深度覆土处理下，3种母岩的成土速率随着土层厚度的增加呈指数函数递减。（7）用野外试验的成土量数据对建立的紫色母岩成土速率模型进行验证，发现在裸露试验处理下马头山组、禄丰组和妥甸组母岩成土量的计算值和实测值的相对误差分别为：8.887%、11.874%和 0.944%，这些误差主要是由于选取的降雨参数和过筛时人工扰动造成。20 cm土层下马头山组、禄丰组和妥甸组母岩成土量的相对误差较大，分别为20.98%、18.84%和26.50%。三组母岩的计算值都小于实测值，主要是因为土壤中母岩干湿交替缓慢或母岩一直处在湿润状态下引起。通过误差分析，发现误差来源主要是野外温湿度数据本身不够精确，而且计算出的相对误差也不大，说明模型是有一定适用性的。
英文摘要	To study the physical mechanism of soil formation in purple patent rock, this paper focused on three typical purple mudstones from the Matou group of Cretaceous red beds(K2m), the Lufeng group of Jurassic red beds(J1l) and the Tuodian group of Jurassic red beds (J3t). These mudstone’s physicochemimal properties were analyzed, and their soil formation rates under varied treatments of temperature, moisture, and hydrothermal interaction were measured in laboratory and outdoor test. Then estimation models for the soil formation rate of three purple mudstones under the physical influence factors were developed. And the models were verified. The main research results are following. (1) The order of the three mudstones’ density, water absorption, the coefficient of water-saturated is J3t > J1l > K2m. The compressive strength of J1l under the air drying and water- saturated condition is the highest. The rank order of particle fractal dimensions of three mudstones are J1l > K2m > J3t., while the pore fractal dimensions are J3t > J1l > K2m. The percentages of clay minerals of K2m, J1l, J3t are 40%, 60% and 48%. The content of SiO2 and Fe2O3 of J1l is higher than that of K2m and J3t, and the content of Al2O3 of J1l is lower than that of K2m and J3t. (2) Results show the purple mudstone disintegration can be classified into three types: collapsing disintegration, exfoliation disintegration and imperceptible disintegration. The rank order of the fractal dimension of three mudstones under the different treatments is the treatment of a combination of saturation and refrigeration-heating (STRH) > saturation (ST) > wetting-drying + refrigeration-heating (WDRH) wetting-drying (WD) refrigeration-heating (RH). And the order of the fractal dimension of disintegration under the same treatments for various mudstones is J3t > K2m > J1l. (3) The soil formation rates of three mudstones increased as the temperature increase, and there was an exponential function relation between the soil formation rate and the constant temperature, and a power-function relation between the soil formation rate and the temperature differences. Under the treatments of same constant temperature and same temperature difference, the order of soil formation rates of three mudstones is J3t > J1l > K2m. Among these treatments, With the changes of temperature different, the soil formation rate of mudstone under the freeze-thaw treatment is the highest, that under big temperature difference treatment is the second, and that under day and night temperature difference treatment is the last. In the freeze-thaw treatment, the contribution of freezing-thawing to disintegration are 56.3%、48.4% and 33.3% for J3t, K2m, and J1l, respectively. Based on these relations, a regression equation between the soil formation rate and temperature was developed. (4) The soil formation rates of three mudstones increased as the mudstone moisture content increase, and showed the power-function relationship between them. Among the three mudstones, the increase rate of J3t was highest, then that of K2m and J1l were lower. When the moisture content is low, the difference of soil formation rate of three mudstones was little. However, the soil formation rate of J3t was obviously faster than other groups when the moisture content is high. Based on these relations, a regression equation between the soil formation rate and mudstone moisture content was developed. (5) To quantificationally analyze the relation between the soil formation rate and integrated effect of temperature and moisture content, the quantitative models of three parent mudstones were developed based on the relation between the rate and the single factor. Then the data of all the test was calculated by using these models Results showed that there was not apparent difference between the measured vaules and the model predicted vaules which was calculated by the model, and the age relative errors for J3t, K2m and J1l are 9.6%、11.6% and 13.2% respectively. It showed that these models could really predict the soil formation rate under different heat-water condition for the three mudstones. (6)In the outdoor test, the soil formation rate of J3t was faster obviously than that of J1l and K2m. When three the mudstone were exposed in the open, their soil formation rate are higher than what they were covered by a transparent tile. It is attributed to that the clay mineral in the mudstones would expand with the increase of the moisture during rain, and then it would contract with losing the moisture in heat-dry climate in Yuanmou, and at the same time, the temperature changes from the day-night, different season, or the air moisture variation would greatly promote the disintegration of purple mudstones. Under the different depth of covering soil, the soil formation rates of three purple mudstones increased by power-function with the decrease of covering soil depth. （7）The results from the comparison of measured soil formation rate in field test and the model predicted, showed that the average relative errors for J3t, K2m and J1l are 20.98%、18.84% and 26.5%, respectively. The predicted soil formation amounts of three mudstones were smaller than the measured, it is because that dry-wet alternation of the mudstones was rather slow when they were covered with the soil, and the mudstones were in a moisture condition at all times. By error analysis, we found that the error was mainly from the field data which could prove imprecise, and the relative error was not big, it showed that the computation module of soil formation rate was applicable when the data of husmidity and temperature could be collected accurately. By error analysis, we found that the error was mainly from the field data which could prove imprecise, and the relative error was not big, it showed that the computation module of soil formation rate was applicable when the data of humidity and temperature could be collected accurately.
语种	中文
公开日期	2013-01-16
资助信息	紫色母岩; 成土速率; 作用机制; 影响因素
内容类型	学位论文
源URL	[http://192.168.143.20:8080/handle/131551/4815]
专题	成都山地灾害与环境研究所_山地灾害与地表过程重点实验室成都山地灾害与环境研究所_山地表生过程与生态调控重点实验室
推荐引用方式 GB/T 7714	张丹. 紫色母岩成土的物理作用机制[D]. 北京. 中国科学院研究生院. 2012.