横缝深止水方案的布设对轴流式机组蜗壳部位的应力影响较大,而深止水方案的布设通常根据工程经验确定,没有统一的规范.止水方案的布设在满足防渗和安全的同时,应选择最优布设使其对蜗壳应力的影响较小.依托某轴流式水电站实际工程,建立厂房的ANSYS三维有限元模型,模拟在机组正常运行和检修工况下,横缝深止水在上游处闭合和上游处联通两种方案的不同止水布设对蜗壳应力的影响.对比两种深止水方案下蜗壳进口断面、内部典型断面和外包混凝土的应力变化,结果表明:随着止水位置的上移,两种深止水方案下的蜗壳应力变化规律相同,但相同的止水位置下,上游联通方案对蜗壳各种应力的减小幅度是上游闭合方案的2 倍以上,横缝深止水布设时可优先采用上游联通方案进行止水.

引入可变模糊集理论进行大坝安全评价工作,以混凝土坝安全监测数据为依托,选取监测中关注度较高的核心指标组建并确立混凝土坝安全评价指标体系及评价标准,采用层次分析法确定各待评指标权重值,建立基于可变模糊集理论的大坝安全评价模型;选取工程实例与其他评价方法进行对比分析,验证了该评价模型的准确性和适用性.结果表明,该方法能够较为全面地反馈大坝安全等级,提高了评价结果的可靠性,评价过程简单、逻辑清晰,具有较强的实用价值.

风电塔筒是风电机组重要支撑结构,其垂直度对机组安全及稳定性有重要影响,塔筒受自然和人为因素的长期影响会出现表面损伤、结构不均匀等现象,塔筒的传统监测方法会产生异常误差而导致测量结果失真.对此,本文采用稳健估计理论分析风电塔筒垂直度,结合最小二乘法拟合塔筒截面测量值的圆心及半径,通过Huber迭代权函数,逐步消除测量值序列存在的粗差、偶然误差等异常测点的影响,并采用实例进行验证.结果 表明:稳健最小二乘法拟合风电塔筒垂直度具有较强的抗差能力,可有效避免粗差、偶然误差等异常测量值的影响,提高了拟合参数和垂直度分析的可靠性,易于编程实现,具有较强的实用价值,该方法可为风力发电塔及类似高耸塔筒的垂直度监测分析提供参考.

大坝监测控制指标关乎其运行安全,对运行期监测数据进行指标拟定具有重要意义.以功果桥大坝为工程依托,通过典型小概率法和统计模型的置信区间法分别计算了典型坝段的坝顶水平位移监控指标,结合设计值与历史极值对监控指标进行了综合拟定.结果表明:典型小概率法计算结果和历史数据较为吻合,置信区间法计算极值范围相对较宽,反映了其变形余量,需结合设计值及外在条件的变化进行综合拟定和修正.研究成果对计算坝体其他监测数据的监控指标具有参考意义,可为大坝运行管理和状态评估提供依据.

简要介绍了华能集团公司水工技术监督工作开展的现状和存在问题,为水工技术监督更好地开展提供参考。

Based on the mechanical theory of unsaturated porous media, an equation of electroosmostic consolidation theory which considers the coupling of electrical field, seepage field and stress field is derived by applying the principles of charge and mass conservation, stress equilibrium equation, Darcy's law and Ohm's law. The equation is discretized by using the Galerkin method of weighted residuals to get the formulation for finite elements; and then a code is developed. A model test of the electroosmosis combining with vacuum drainage is simulated. The simulated results agree well with the measured ones; it is shown that the proposed theory can predict the development of pore water pressure and displacements quantitatively in the electroosmosis consolidation process.

Based on the characteristics of dredger fill soil with high water content,high compressibility,and low permeability,this paper proposes a method of vacuum preloading in combination with electroosmosis for the reinforcement of a soft soil foundation.The preliminary investigation was made into the reinforcement mechanism through a laboratory model test.The results show that electroosmosis can effectively accelerate the drainage of the soil foundation when the water content of the soil sample reaches the optimal critical value of 0.85 after the vacuum preloading at the preliminary stage.Obvious vertical and lateral deformation as well as the increase of soil strength near the electrodes can be observed when using this method to treat dredger fill soil.Therefore,for solving the problem that vacuum preloading can only used to effectively reinforce the surface soil with a thickness of about 42.8% of the reinforced depth,the proposed method can be used to reinforce both the surface and deep soils,by vacuum preloading and electroosmosis,respectively,and can thus uniformly reinforce the soil foundation in the depth direction.

An analytical consolidation theory of soft ground under vacuum preloading combined with electro-osmosis was established based on the Terzaghi's consolidation theory and the Esrig's electro-osmotic consolidation theory.The analytical solutions of the excess pore water pressure of the soft ground during consolidation process were obtained.Through an example,the development of the excess pore water pressure with the time and its distribution rules between the electrodes induced by the vacuum preloading combined with electro-osmosis were analyzed.Model tests on soil samples under the vacuum preloading combined with electro-osmosis were carried out.The observed water content of the soil samples after tests agree with those derived by means of the analytical solutions of the excess pore water pressure.They have similar distribution rules,indicating that the analytical consolidation theory is rational.

This paper introduces the laboratory electro-osmosis test on ultra-soft soil in Dayao Bay,Dalian,and determines the electric current density that can achieve a good electro-osmotic effect through experiments.The experimental research has shown that there is a good linearity between electro-osmotic water discharge rate and power-on current as well as a better correlation between water discharge rate and temperature;in the later period of test,the intermittent power-on current can improve the electro-osmotic effect significantly;and the micro-cracks generated during electro-osmosis is closely related to the electric potential distribution.

The electrical resistivity of three different kinds of soil samples under the same consolidated pressure and temperature was measured by use of the Miller Soil Box.The influences of water content and potential gradient on the electrical resistivity of soil samples were investigated.A formula for the electrical resistivity of soils was established.The test results indicate that the electrical resistivity of soils is greatly related to the water content.When the water content is larger than the liquid limit of soils,the electrical resistivity of soils is relatively small and varies little with the water content.When the water content is less than the liquid limit,the electrical resistivity of soils is relatively large and rapidly increases with the decrease of the water content.For the soils with certain water content,the electrical resistivity of soils decreases with the increase of the potential gradient.