地震研究

泥炭质土在昆明盆地分布广泛,由于其工程性质差,因此其土动力学性质受到许多学者的重视。首先收集近年来昆明盆地内埋深为0～100 m的62个取样点,128组泥炭质土样的动三轴实验数据进行统计分析,得到了泥炭质土的不同剪应变下的动剪切模量比和阻尼比的统计值; 然后讨论土动力学参数随埋深的变化特征,并与《工程场地地震安全性工作规范》给出的黏土值、粉质黏土值、淤泥质黏土值进行了对比; 最后在昆明盆地内挑选了2个典型钻孔模型,分别输入统计值、实测值、规范黏土值、粉质黏土值、淤泥质黏土值,进行一维土层反应分析计算。结果表明:规范给出的黏土值、粉质黏土值、淤泥质黏土值与泥炭质土实测值得到的结果差异较大,泥炭质土统计值与实测值得到的结果差异较小。当现场工作取样困难,得不到可供试验的原状样时,可考虑选择使用本文的泥炭质土统计值。

Peat soil are widely distributed in the Kunming Basin,but its engineering properties are poor,and its dynamic properties are valued by many scholars.In this paper,the dynamic parameters of peat soil in the Kunming basin are collected,and statistical analysis is made to obtain the statistical values of shear modulus ratio G/Gmax and damping ratio λ of peat soils.We selected two typical borehole models in the Kunming basin,entered the statistical values or measured values,and used the one-dimensional soil response analysis to calculate.The results of the statistical values calculated were not different from the results of the measured values calculated.If it is difficult to get the original sample that can be tested,one can consider using the statistical values of this paper.

引言
1 数据统计分析
2 泥炭质土动力学参数统计值适用性分析
3 结论

图1 昆明盆地泥炭质土取样点分布图<br/>Fig.1 Distribution map of engineering sites of peaty soil in the Kunming basin

图1 昆明盆地泥炭质土取样点分布图
Fig.1 Distribution map of engineering sites of peaty soil in the Kunming basin

表1 不同埋深区间泥炭质土样本量分布及分组<br/>Tab.1 Total sample numbers and groups of the peaty soil at different depth ranges

表1 不同埋深区间泥炭质土样本量分布及分组
Tab.1 Total sample numbers and groups of the peaty soil at different depth ranges

表2 不同埋深区间泥炭质土的统计平均值<br/>Tab.2 The mean values of dynamic parameters of the peaty soil at different depth ranges

表2 不同埋深区间泥炭质土的统计平均值
Tab.2 The mean values of dynamic parameters of the peaty soil at different depth ranges

图2 不同埋深区间泥炭质土动剪切模量比(a)、阻尼比(b)变化曲线<br/>Fig.2 The diagrams of dynamic shear modulus ratio(a),damping ratio(b) of the peaty soil at different depth ranges

图2 不同埋深区间泥炭质土动剪切模量比(a)、阻尼比(b)变化曲线
Fig.2 The diagrams of dynamic shear modulus ratio(a),damping ratio(b) of the peaty soil at different depth ranges

图3 不同剪应变下泥炭质土动剪切模量比随埋深的变化图<br/>Fig.3 The diagram of shear modulus ratio of the peaty soil varying with depth

图3 不同剪应变下泥炭质土动剪切模量比随埋深的变化图
Fig.3 The diagram of shear modulus ratio of the peaty soil varying with depth

图4 不同剪应变下泥炭质土阻尼比随埋深的变化图<br/>Fig.4 The diagrams of damping ratio of the peaty soil varying with depth

图4 不同剪应变下泥炭质土阻尼比随埋深的变化图
Fig.4 The diagrams of damping ratio of the peaty soil varying with depth

图5 泥炭质土统计值分别与94规范给出的黏土(a)、粉质黏土(b)、及淤泥质黏土(c)的土动力学参数对比曲线<br/>Fig.5 Relationship of soil dynamic parameters between the peat soil and clay(a),silt clay(b),and muddy soil(c)

图5 泥炭质土统计值分别与94规范给出的黏土(a)、粉质黏土(b)、及淤泥质黏土(c)的土动力学参数对比曲线
Fig.5 Relationship of soil dynamic parameters between the peat soil and clay(a),silt clay(b),and muddy soil(c)

表3 场地模型1土层剖面参数
Tab.3 Soil profile parameters of the site model 1

表4 场地模型2土层剖面参数
Tab.4 Soil profile parameters of the site model 2

图6 场地基岩不同超越概率反应谱<br/>Fig.6 Site rock response spectrum curves with different exceedance probabilities

图6 场地基岩不同超越概率反应谱
Fig.6 Site rock response spectrum curves with different exceedance probabilities

表5 场地模型1和模型2概率峰值加速度结果<br/>Tab.5 The peak ground acceleration of the site model 1 and model 2

表5 场地模型1和模型2概率峰值加速度结果
Tab.5 The peak ground acceleration of the site model 1 and model 2

表6 4种土动力学参数取值与实测值所得峰值加速度结果的偏差(%)<br/>Tab.6 Deviation of peak ground acceleration between 4 schemes of soil dynamic parameters(%)

表6 4种土动力学参数取值与实测值所得峰值加速度结果的偏差(%)
Tab.6 Deviation of peak ground acceleration between 4 schemes of soil dynamic parameters(%)

图7 场地模型1(a)和模型2(b)地表 50年3种概率加速度反应谱<br/>Fig.7 The horizontal acceleration response spectrum curves of site model 1 and model 2

图7 场地模型1(a)和模型2(b)地表 50年3种概率加速度反应谱
Fig.7 The horizontal acceleration response spectrum curves of site model 1 and model 2

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备注

引言

1 数据统计分析

2 泥炭质土动力学参数统计值适用性分析

3 结论

期刊信息