Application of performance data from evaporite mines to salt nuclear waste repository design     

John F. Abel Jr  Farrokh Djahanguiri 《Geotechnical and Geological Engineering》1984,2(4):323-340

Summary Data on the performance of operating mines in rock salt and potash from United States and British sources is reviewed. A design validation scheme for nuclear waste repositories is proposed, based on back analysis of the response of operating evaporite mines.  相似文献   

辽宁省长程水氡资料动态特征及其与地震活动的关系探讨     

王海燕  黄辅琼  曹凤娟 《东北地震研究》2006,22(3):44-51

对以地震预报为目的而开展的辽宁省盘锦、岫岩、汤池三个水氡点的长程观测资料做系统分析,总结了资料多年动态特征,并就其变化与地震活动关系进行研究;以及岫岩地震前后水氡异常变化与震源应力场关系进行了探讨。结果表明:水氡异常的幅度可能反映地震活跃期的强震活动水平;浅层地下流体观测可以反映地壳深部活动的力学过程。  相似文献   

Coalescence of offset rock joints under biaxial loading     

Omer Mughieda  Iyad Karasneh 《Geotechnical and Geological Engineering》2006,24(4):985-999

Crack coalescence in rock masses was studied by performing a series of biaxial compresion tests on specimens made of rock-like material. Specimens of size 63.5 × 27.9 × 20.3 cm, made of 72% silica sand, 16% cement (Type I) and 12% water by weight were tested. The joint inclination angle was maintained at 45°, while the offset angle i.e. angle between the plane of the joint and the line that connects the two inner tips of the joints, was changed from 0° to 90° with an increment of 15°. Three levels of lateral stress were used; 0.35 MPa, 0.7 MPa and 1.5 MPa on each sample. HP data acquisition system was used to record the data for each sample. In each sample, four LVDTs were fixed to measure the axial and lateral displacement along the sample. The failure mechanisms were monitored by eye inspection and a magnifier to detect crack initiation and propagation. For each test, the failure surfaces were investigated to determine the characteristics of each surface. Wing cracks initiated at the tip of the joint for the low confining stress applied, while at higher confining stresses wing cracks also initiated at the middle of the joint. Secondary cracks initiated at the tip of the joint due to shear stress. Three modes of failure took place due to coalescence of the secondary and wing cracks. The bridge inclination was the main variable that controlled the mode of failure. For bridge inclination of 0°, the coalescence occured due to shear failure and for bridge inclination of 90° the coalescence occurred due to tensile failure while for the other bridge inclinations coalescence occured due to mixed tensile and shear failure.  相似文献   

On a viscoplastic model for rocks with mechanism-dependent characteristic times     

A. F. Fossum  R. M. Brannon 《Acta Geotechnica》2006,1(2):89-106

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高温超导磁强计研制及在瞬变电磁法中的应用   总被引：1，自引：0，他引：1  

陈晓东  赵毅  邓晓红  吕国印  张杰  赵敬洗 《物探与化探》2006,30(3):229-232

高温超导磁强计具有直接测量磁场、低噪声、高灵敏度、动态范围大、频带宽低频响应好的特点,可以取代感应线圈作瞬变电磁法的接收传感器。在理论上,高温超导磁强计应用在瞬变电磁法中具有优势。以高温超导磁强计作收传感器和以感应线圈作收传感器,在瞬变电磁法上进行了大量的野外对比试验,结果表明:把高温超导磁强计应用于瞬变电磁法(TEM)勘探上,能够加大勘探深度。  相似文献   

油气田地质灾害研究纲要     

徐守余 《中国地质灾害与防治学报》2006,17(1):119-123

油气田地质灾害是地质灾害的一种特殊类型。是指在特定的地质背景下因勘探、开发和利用油气资源的工程活动而诱发形成的灾害性地质事件。油气田地质灾害具有诱发性、突发性、成因多样性、可预防性和日趋显著性等特征。对油气田地质灾害分类尚未形成一致的认识,可按灾害的载体和外在表现、空间分布状况、分布范围及动力作用等多种因素进行分类。油气田地质灾害的形成机制是复杂的、多种多样的,主要有构造动力形成机制及非构造动力形成机制两大类。油气田地质灾害受地应力、油气地质环境及工程活动等多方面因素的控制和制约。对其防治应遵循油气田勘探开发与灾害防治并重等原则,深化地质研究,采取适当监测手段,并制定合理的油气资源勘探开发方案,将油气田地质灾害防患于未然。同时还应对油气田地质灾害进行有效预测预报以及恰当评估。  相似文献   

True Triaxial Stresses and the Brittle Fracture of Rock   总被引：3，自引：0，他引：3  

Bezalel Haimson 《Pure and Applied Geophysics》2006,163(5-6):1101-1130

This paper reviews the efforts made in the last 100 years to characterize the effect of the intermediate principal stress σ ₂ on brittle fracture of rocks, and on their strength criteria. The most common theories of failure in geomechanics, such as those of Coulomb, and Mohr, disregard σ ₂ and are typically based on triaxial testing of cylindrical rock samples subjected to equal minimum and intermediate principal stresses (σ ₃=σ ₂). However, as early as 1915 Böker conducted conventional triaxial extension tests (σ ₁=σ ₂) on the same Carrara marble tested earlier in conventional triaxial compression by von Kármán that showed a different strength behavior. Efforts to incorporate the effect of σ ₂ on rock strength continued in the second half of the last century through the work of Nadai, Drucker and Prager, Murrell, Handin, Wiebols and Cook, and others. In 1971 Mogi designed a high-capacity true triaxial testing machine, and was the first to obtain complete true triaxial strength criteria for several rocks based on experimental data. Following his pioneering work, several other laboratories developed equipment and conducted true triaxial tests revealing the extent of σ ₂ effect on rock strength (e.g., Takahashi and Koide, Michelis, Smart, Wawersik). Testing equipment emulating Mogi's but considerably more compact was developed at the University of Wisconsin and used for true triaxial testing of some very strong crystalline rocks. Test results revealed three distinct compressive failure mechanisms, depending on loading mode and rock type: shear faulting resulting from extensile microcrack localization, multiple splitting along the σ ₁ axis, and nondilatant shear failure. The true triaxial strength criterion for the KTB amphibolite derived from such tests was used in conjunction with logged breakout dimensions to estimate the maximum horizontal in situ stress in the KTB ultra deep scientific hole.  相似文献   

Probabilistic analysis of borehole closure for through-salt well design     

A. F. Fossum  J. T. Fredrich 《Acta Geotechnica》2007,2(1):41-51

Probability levels, in the form of marginal cumulative distribution functions, are determined for the time it takes salt to contact a casing, which penetrates a salt canopy, and the time it takes the casing to yield once salt has contacted the casing, in support of through-salt well design activities required for deep-water, sub-salt environments. The finite-element method coupled with an advanced reliability method is used to perform the analyses. Randomness caused by uncertainties in salt properties, lithostatic stress, drilling-mud pressure, production temperature, and borehole ellipticity is handled by including statistics and probability distributions for each of these random variables. The advanced reliability method takes full account of the random variables and processes without Monte Carlo simulation, by using a method for assessing reliability statistics that computes response probabilities in a direct and efficient manner. This advanced reliability method falls under the general category of fast probability integration schemes.  相似文献   

Modeling of pile installation using contact mechanics and quadratic elements   总被引：1，自引：0，他引：1  

Kathrin A. Fischer  Daichao Sheng  Andrew J. Abbo 《Computers and Geotechnics》2007,34(6):449-461

In geotechnical engineering, numerical analysis of pile capacity is often performed in such a way that piles are modeled using only the geometry of their final position in the ground and simply loaded to failure. In these analyses, the stress changes caused by the pile installation are neglected, irrespective of the installation method. For displacement piles, which are either pushed or hammered into the ground, such an approach is a very crude simplification. To model the entire installation process of displacement piles a number of additional nonlinear effects need to be considered. As the soil adjacent to the pile is displaced significantly, small deformation theory is no longer applicable and a large deformation finite element formulation is required. In addition, the continuously changing interface between the pile and the soil has to be considered. Recently, large deformation frictional contact has been used to model the pile installation and cone penetration processes. However, one significant limitation of the analysis was the use of linear elements, which have proven to be less accurate than higher order elements for nonlinear materials such as soils.

This paper presents a large deformation frictional contact formulation which can be coupled consistently with quadratic solid elements. The formulation uses the so-called mortar-type discretisation of the contact surfaces. The performance of this contact discretisation technique is demonstrated by accurately predicting the stress transfer between the pile and the soil surfaces.  相似文献   

Two-dimensional development of the dynamic coupled consolidation scaled boundary finite-element method for fully saturated soils     

Mahmoud Hassanen  Ashraf El-Hamalawi 《Soil Dynamics and Earthquake Engineering》2007,27(2):153-165

The scaled boundary finite-element method is a powerful tool used to analyse far-field boundary soil–structure interaction problems. In this paper, the method is extended to include Biot's coupled consolidation in order to deal with fully saturated soil as a two-phase medium. The advantages of this method are explained in this paper. The detailed formulation considers the general two-dimensional (2D) analysis case, accounting for body forces and surface tractions in both bounded and unbounded media.  相似文献