上海地区扁铲侧胀试验计算地基承载力的探讨

通过对扁铲侧胀试验和试验机理的研究和对试验指数的对比分析 ,提出了用扁铲侧胀试验计算地基承载力的方法 ;利用上海地区部分重大工程中的扁铲侧胀试验数据 ,在与室内土工试验、静力触探试验及十字板剪切试验的相关分析的基础上 ,经数理统计后给出了上海地区用扁铲侧胀试验计算地基承载力的经验公式。最后 ,通过与室内土工试验、静力触探试验和十字板剪切试验计算的地基承载力对比 ,分析了本经验公式计算地基承载力的精度。研究分析表明 ,可以用扁铲侧胀试验计算地基承载力     

台风“利奇马”对钻孔体应变的扰动分析——以浙江地区为例

利用台风“利奇马”过境浙江期间,岱山地震台、东阳地震台钻孔体应变数据,采用数据滤波和线性回归等方法,分析了这2个台站钻孔体应变对台风的响应特征。结果表明,东阳地震台受台风引起的低气压的影响,钻孔体应变与气压同步变化;而岱山地震台受低气压和降水的共同影响,钻孔体应变与气压在变化的相关性和同步性上均有差异。气压和降水导致钻孔体应变的变化量可以通过负载力学模型进行估算求解。     

扁铲侧胀试验估算地基承载力初探

通过大量扁铲侧胀试验的测试数据，以静力触探比贯入阻力Ps为桥梁，建立了扁铲侧胀试验扁铲模量ED与地基承载力特征值fak之间的经验公式，最后通过实测数据对本经验公式进行了验证。     

利用扁铲侧胀试验确定粗粒砂土的超固结比

本文利用扁铲侧胀试验对超固结砂土的土力学参数进行测试,目的是获取砂土的超固结比OCR和静止土压力系数k_0。经过一系列室内试验箱砂土物理模型试验的精确测试,分别得到在加载和卸载阶段的P_0压力值和P_1压力值,并换算成各项扁铲侧胀试验指标。试验结果表明,在扁铲侧胀试验指标中,侧胀水平应力指数K_D更能反映粗颗粒砂土的超固结比,因此,可用相对密实度D_r和侧胀水平应力指数K_D建立超固结比OCR的表达式;由于K_D/k_0和E_D/σ'_m之间有共同的因子,即状态参数ψ,因此可建立两者的关系式来计算静止土压力系数k_0。     

Interpretation of dilatometer tests in a heavy oil reservoir

This paper presents a prospective study for identifying selected parameters of the modified Cam‐Clay model representing the behaviour of heavy oil reservoirs. The first part shows that the plastic compressibility, which controls the main recovery mechanism of such reservoirs, can be accurately determined, simultaneously with other parameters, by an inverse analysis of pressure–strain curves. The conditions of the identification procedure mainly involve two tests conducted under different drainage conditions or at different strain rates. The numerical study also establishes the sequence of an original in situ experimental program, in which three dilatometer tests at a relatively great depth (several hundreds of metres) were carried out. The comparison of the experimental data with the numerical computations reveals a significant over‐consolidation ratio which does not allow the plastic compressibility to be determined but supports the findings regarding the geological erosion of the site. Copyright © 2006 John Wiley & Sons, Ltd.     

利用体应变观测智利8.8级大地震激发的地球球型自由振荡

用河北省体应变的数字化观测资料,利用功率谱密度估计方法,在没有对资料进行处理的情况下,准确获得了2010年2月27日智利8.8级大地震激发的0S5-0S35摹频球型自由振荡,并与地球初步参考模型(PREM)的理论自由振荡频率进行对比,发现实测振荡频率与PREM预测的振荡频率基本符合.河北省体应变的数字化观测资料的确可以...     

扁铲侧胀试验在浅海钙质土力学特性评价中的应用

利用扁铲侧胀仪对海底浅层钙质土进行原位测试,能够一次获得多个评价土性的试验参数。试验表明,由于波浪循环动荷载的作用使得海底表层（深1～2 m）钙质砂的密实度比其紧邻的下部偏大,以珊瑚礁为主要胶结物的钙质土,内部具有大的孔隙或松散堆积体结构是造成海底浅层钙质砂表层与浅部土体的扁铲侧胀压力明显变化的主要原因。扁铲试验结果与现场标准贯入试验具有较好的相关性,基于Seed公式推导的适合于计算水下平均动应力比的简化公式能够较好地用于对不同地震烈度下海底浅层钙质土液化可能性的判别。     

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Soil exploration in a 500 m deep fjord,Western Norway

Abstract

A number of engineering organizations and individuals have contributed toward a comprehensive feasibility study made in 1973–1974 in connection with a submerged floating tunnel project in Norway. The tunnel is planned to cross the 500 m deep Eidfjord in Hardanger over a length of about 1.3 km. The main findings from geophysical explorations, subsoil sampling operations, and an extensive laboratory testing program on extracted soil samples are described here.

A main part of this paper is devoted to the study of a full‐scale field test with a gravity anchor block weighing 180 tonne. This study reports on the behavior of the block during launching from its sloping construction ground, the sinking operation, and the behavior of the block after it reached the bottom at 450 m depth. Observations of settlement and tilt are available, and a comparison is made between the observed and computed behavior. Broadly speaking, a fairly good agreement was found.     

Use of the dilatometer test to estimate the maximum shear modulus of normally consolidated Busan clay

ABSTRACT

The aim of this experimental study is to estimate the maximum shear modulus (G_max) of normally consolidated clayey soils using the results of a dilatometer test (DMT). A series of DMTs was conducted at the Busan New Port and Noksan sites in South Korea. In addition, basic index tests, bender element tests (i.e., shear wave velocity (V_s) measurements), and standard 1-D consolidation tests were performed using the undisturbed specimens. The results demonstrate that the G_max of normally consolidated Busan clays cannot be adequately captured by the horizontal stress index (K_D)-based empirical formula. Therefore, a G_max estimating formula for normally consolidated clayey soils is newly suggested in this study using the dilatometer constrained modulus (M_DMT) and stress-normalized material index (I_D). Most notably, the estimated G_max values using the suggested formula are comparable with the measured G_max of both this study and the previous study on normally consolidated clayey soils.