计算锚索抗滑桩变形及内力的一种新方法

结合结构力学和弹性地基梁理论,考虑锚索的弹性变形,建立了一种计算锚索抗滑桩变形及内力的新方法。在建立公式时,将抗滑桩从滑面处分为上、下两部分;对嵌固段的桩按弹性地基梁计算,滑面以上的桩用力法计算;利用滑面处的变形协调条件,建立了锚索抗滑桩的计算公式,所得公式可以方便地用于求解锚索的设计拉力、抗滑桩的内力及变形。最后,以某滑坡治理工程为例,计算了锚索拉力及抗滑桩的内力,验证了计算方法的可靠性,并与普通抗滑桩的计算结果进行了对比分析。     

基于“三段法”的锚拉桩桩身内力计算方法与应用

针对抗滑桩常因地质条件、地形地貌等原因导致受荷段底面与嵌固段顶面不在同一水平面的情况,将此段划为次受荷段,并推导了次受荷段桩后设计荷载大小计算公式和荷载分布公式,以及在弹性地基梁和悬臂梁模型下的适用于悬臂桩和锚索桩内力与挠度计算通用公式。以巴东县焦家湾移民安置点库岸防护工程预应力锚索桩为例,研究次受荷段对抗滑桩内力和挠度影响。结果表明:忽略次受荷段后土压力作用的传统计算方法会使桩身弯矩计算结果偏小,导致桩身配筋量不足,存在设计安全隐患。再以锚索排数、位置为控制变量,研究其对预应力锚索桩内力和挠度的影响,提出预应力锚索可有效地降低抗滑桩工程造价;增加预应力锚索的排数有利于调节抗滑桩内力分布,设计时应优先考虑将锚索设置为多排锚索。      

紫阳滑坡治理工程实例分析

本文介绍紫阳骨坡治理工程中有关抗滑桩的设计与施工。文中详细地论述了设计中设计人员应根据工程的具体情况去灵活处理的一些技术问题，如确定有关参数的选择原则，计算上的条件简化和一些具体技术细节的处理方法等．     

基于统一强度理论多层滑坡体中抗滑桩最大桩间距研究

抗滑桩是防治滑坡的重要工程措施之一,桩间距是抗滑桩设计中的一个重要参数。已有的桩间距研究主要是针对单层均质滑坡,但实际工程中多数滑坡体是多层的,因此对多层滑坡体抗滑桩桩间距的研究就显得尤为重要。在研究多层滑坡体中的抗滑桩最大桩间距时,在确定滑坡体中的最危险滑体后,考虑多层滑体相互作用,运用滑坡推力分布函数及土体抗力分布函数对最危险滑体进行了受力分析,基于统一强度理论对最危险滑体的平衡条件与土拱强度条件进行了研究,推导出了抗滑桩最大桩间距方程。最后对2个实例进行了计算,计算实例1说明了该计算方法在计算多层滑坡体中最大桩间距时,计算结果偏于安全,计算实例2厚坝滑坡验证了运用滑坡推力分布函数使最大桩间距计算结果更合理。      

预应力锚索+抗滑桩在滑坡治理中的应用

在对南三路一虎陇山段滑坡进行稳定性分析与评价的基础上,通过对滑坡治理方案选型分析,提出预应力锚索+抗滑桩是一种在坡高较大且场地紧张等不利情况下进行滑坡治理的有效措施.同时,扼要介绍了预应力锚索+抗滑桩施工步骤.     

锚索抗滑桩系统内力变形研究

在对锚索抗滑桩系统内锚索与抗滑桩受力状态综合分析的基础上,认为锚索的拉伸变形对锚索抗滑桩系统的内力及变形存在一定影响,基于锚索与抗滑桩的变形协调原理,提出了锚索拉力及其变形的计算方法,推导了抗滑桩桩身位移和内力的计算公式,并将该方法用于工程实例分析。通过与其他方法比较,说明使用该方法计算锚索抗滑桩的合理性和经济价值,并分析了锚索变形以及拉力大小对锚索抗滑桩系统内力变形的影响,所得结果已得到后期模型试验的数据支持。     

图表法在边坡抗滑桩设计中的应用

抗滑桩作为加固滑坡体的一种有效措施,与其它抗滑工程如抗滑挡墙、锚杆等相比,具有抗滑能力强、施工安全简便,并能进一步核实地质条件等突出优点,现已广泛应用于边坡工程中,但其设计方法还不成熟.运用图表法分析简化了某土质边坡抗滑桩设计计算,这种方法对以后的抗滑桩设计以及进一步深入研究具有一定的参考意义.     

三角网数字地面模型与农田平整设计

针对农田水利工程中农田纵横坡度设计与填挖土方计算问题，本文提出了三角网地面模型，推证了地面坐标转化为设计面坐标的坐标转化公式及三角形模型体积计算公式，给出了设计计算的逐步趋近算法。     

某滑坡稳定分析及处理方案探讨

滑坡属于不良地质现象，是斜坡上的部分岩体和土体在自然或人为因素的影响下沿某一明显的界面发生剪切破坏向坡下运动的现象。当高速公路不得不通过某一滑坡时，对其稳定性进行分析和整治设计就显得尤为重要。以祁临高速公路灵石至霍州段窑深沟大桥东南窑深沟滑坡为实例，根据勘察资料，利用岩土力学知识，在公路修好后并运行的情况下，计算出了其稳定系数和推滑力，又以材料力学、结构力学等力学理论为基础，设计出抗滑桩和锚索抗滑桩等两种整治方案，经验证，效果良好。     

滕州郭庄煤矿十二采区第十下层灰岩水赋存规律及涌水量预测

采区涌水量是采区排水系统设计的依据，涌水量的准确与否，直接涉及到采区开采的安全。该文对十，层灰岩的涌水规律、补给条件进行了分析，并采用比拟法及大井法对采区涌水量进行了计算，预计了采区正常涌量和最大涌水量，为采区排水设计提供依据。     

Dynamic response of a slope reinforced by double-row antisliding piles and pre-stressed anchor cables

Large-scale shaking table tests were conducted to study the dynamic response of a slope reinforced by double-row anti-sliding piles and prestressed anchor cables. The test results show that the reinforcement suppressed the acceleration amplification effectively. The axial force time histories are decomposed into a baseline part and a vibration part in this study. The baseline part of axial force well revealed the seismic slope stability, the peak vibration values of axial force of the anchor cables changed significantly in different area of the slope under seismic excitations. The peak lateral earth pressure acting on the back of the anti-sliding pile located at the slope toe was much larger than that acting on the back of the anti-sliding pile located at the slope waist. The test results indicate an obvious load sharing ratio difference between these two anti-slide piles, the load sharing ratio between the two anti-sliding piles located at the slope toe and the slope waist varied mainly in a range of 2-5. The anti-slide pile at the slope waist suppressed the horizontal displacement of the slope surface.     

乔木种植方式对护坡效果影响试验研究

近年来, 植被护坡作为一种生态友好型支护方式越来越多地被应用到斜坡支护工程中, 故如何科学地种植植被以充分发挥其护坡效果具有重要的研究意义。为此, 以乔木为研究对象, 结合3D打印技术制备乔木根系模型, 通过自行设计的滑坡模型试验系统, 开展了系统物理模型试验, 对3种根系排布方式与3种根系间距下乔木的护坡效果进行了研究。结果表明: ①在乔木根系支护下, 抗滑力峰值增大, 达到峰值的时间延长, 峰后抗滑力衰减程度降低。②对抗滑力的改善效果方面, 反拱型排布>正拱型排布>直线型排布>无根系支护。根系间距S=1.5D(D为根系间最大水平距离, D=7cm)与S=2.0D对抗滑力的改善效果接近, S=2.5D时抗滑力峰值最大。③就根系排布方式而言, 反拱型排布对坡体位移的改善效果最为明显, 正拱型排布与直线型排布对位移的改善效果接近; 就根系间距而言, S=2.5D对坡体位移的改善效果最为明显, S=1.5D与S=2.0D对坡体位移的改善效果接近。④直线型排布下坡体滑动范围增大, 正拱型排布与反拱型排布则能有效限制坡体变形。根系间距对坡体变形场的影响不大。综上可知, 在乔木护坡工程中可通过控制乔木的排布方式与根系间距来提升其护坡效果。      

岩质边坡平面滑动锚固方向角的三维优化方法

以岩质边坡中常见的平面滑动为研究对象,研究其最优锚固方向角的计算方法。将锚索自由段单位长度能提供的最大抗滑增量作为目标控制变量,将坡面和滑动面特征参数与锚索设计参数作为优化控制自变量,通过坐标系转换得到的线性方程组对锚索的预拉力进行分解,并根据锚索支护时的三维模型建立了锚索自由段长度的优化公式,进而推导了用于锚固方向角三维优化的新计算方程。在该方程的基础上借助MATLAB软件中的fmincon函数对锚索加固方向不受限制时的锚固方向角进行了优化。最后通过锚固方向角敏感性分析与工程实例分析相结合,证明了推荐的最优锚固方向角计算方法的有效性与先进性。新方法有效地解决了边坡坡面与滑动面走向存在夹角时最优锚固方向角的求解问题,可进一步提高锚索的锚固效益,降低边坡的支护费用。      

Study on distribution rule of sliding pushing force and remnant resistant sliding force acting on anti-sliding pile

Anti-slide pile is one of the important methods to administer landslide geological disaster because of its advantages.It plays important role in administering landslide.It is a premise of reasonable economy and technological advance to know the distribution rule and feature of the force between anti-sliding pile and surrounding rock.To determine the sliding force and remnant resistant sliding force,according to need of study,this paper sets up the geological model and mechanics model in term of a typical landslide,and analyzes the effect rule of sliding body distortion,strength and gravity to the pushing force and remnant resistant sliding force by use of the numerical model.The distribution rule of pushing force and remnant resistant sliding force of the type of landslide is given.     

Study on distribution rule of sliding pushing force and remnant resistant sliding force acting on anti-sliding pile

Anti-slide pile is one of the important methods to administer landslide geological disaster because of its advantages. It plays important role in administering landslide. It is a premise of reasonable economy and technological advance to know the distribution rule and feature of the force between anti-sliding pile and surrounding rock. To determine the sliding force and remnant resistant sliding force, according to need of study, this paper sets up the geological model and mechanics model in term of a typical landslide, and analyzes the effect rule of sliding body distortion, strength and gravity to the pushing force and remnant resistant sliding force by use of the numerical model. The distribution rule of pushing force and remnant resistant sliding force of the type of landslide is given.     

考虑降雨滑坡多级滑动的改进传递系数法研究

在多级滑坡的渐进破坏过程中, 滑带不同部位的屈服程度和破坏模式不同, 强度参数也不同。在强降雨条件下, 坡表产生的张拉裂缝充水, 会产生静水压力。当前广泛应用的传递系数法对滑带不同位置取同一强度参数, 也尚未考虑到静水压力作用。为此提出了一种考虑静水压力作用和滑带不同部位强度参数差异的改进传递系数法, 对降雨引起的西安市柳西村南部的牛角沟滑坡进行了计算。结果表明: 与不考虑静水压力和滑带不同部位强度参数差异的计算方法比, 改进传递系数法计算的抗滑力相对较小, 剩余下滑力计算结果相对较大, 各级滑坡稳定性系数分别减小了约33.26%、17.92%、24.95和16.94%;而改进前的稳定性系数偏高, 可能会导致支挡工程的安全储备不足。本研究提出的改进传递系数法可为多级滑坡处置提供更安全的参考。      

上硬下软地层中h型桩与滑坡相互作用机理模型试验研究

组合式抗滑桩是加固大型滑坡的有效防护措施, 但上硬下软等复合地层中h型抗滑桩的加固机理仍有待深入研究。基于一套自主研发的上硬下软地层滑坡-h型抗滑桩物理模型试验装置, 综合应力应变监测、激光测距仪、高速相机与粒子图像测速(PIV)技术研究了上硬下软地层滑坡中h型桩的位移、内力响应规律与滑体变形破坏特征, 揭示了上硬下软地层条件下h型桩与滑坡相互作用机理。研究结果表明, 在坡顶荷载逐渐增加的条件下, h型桩加固的上硬下软地层滑坡的演化阶段可划分为蠕变阶段、匀速变形阶段、加速变形阶段和破坏阶段4个阶段。受连系梁影响, 前排桩与后排桩桩顶位移较小, 应变最大值出现在靠近滑面深度处; 后排桩弯矩呈"S"型分布, 前排桩弯矩呈三角形分布, 负弯矩最大值位于连系梁下方20 cm处。随着硬岩体积分数(φ_β)增加, 桩顶位移逐渐减小, 前、后排桩最大弯矩值也逐渐减小, 但硬岩体积分数超过60%后最大弯矩值变化幅度较小。当φ_β=20%和40%时, 后排桩土压力总体呈抛物线形式; 当φ_β=60%和80%时, 土压力总体呈反"S"型, 且滑面附近出现第二个土压力峰值; 前排桩土压力分布形式均为抛物线型。试验结果可为组合式抗滑桩加固机理研究和设计提供理论支撑。      

Mechanism of colluvial landslide induction by rainfall and slope construction: A case study

The landslide hazards occurring in the complex geological genesis accumulation body are usually controlled by the coupling action of many internal and external factors. Therefore, this paper takes the dam-front Danbo accumulation body landslide of Yangfanggou hydropower station on the Yalong River as the geological prototype, and discusses the process and mechanism of slope stability degradation under the combined action of rainfall and slope construction. Based on the detailed understanding of the basic characteristics of the accumulation body, the development characteristics of the landslide and the construction situation of the slope engineering, the study conducted correlation analysis between rainfall and landslide displacement, the physical and mechanical tests of all types of rocksoil masses, and the numerical simulation testing of seepage field variation of the landslide section. It is found that the special slope structure and material composition of the old landslide accumulation layer on the upper part of the Danbo accumulation body are the internal factors for the occurrence of thrust loadinduced landslide, and the construction of the slope engineering not only creates free space conditions for sliding, but also provides channels for the infiltration of rainfall into the slope after confluence, which is an external factor that caused the mechanical properties of the sliding zone soil to gradually weaken from the trailing edge to the leading edge. The geomechanical model of such landslide is that the active section of the trailing edge produces the "source of force", the transition section of the middle section affects the occurrence of sliding, and the anti-sliding section of the leading edge controls the occurrence of landslide hazards. The results of this research provide not only a useful supplement to the theory of landslide formation mechanisms but also a scientific basis for guiding the prevention and control of similar hazards.     

Estimating Design Loads with Environmental Contour Approach Using Copulas for an Offshore Jacket Platform

Jacket-type offshore platforms are widely used for oil, gas field, and energy development in shallow water. The design of a jacket structure is highly dependent on target environmental variables. This study focuses on a strategy to estimate design loads for offshore jacket structures based on an environmental contour approach. In addition to the popular conditional distribution model, various classes of bivariate copulas are adopted to construct joint distributions of environmental variables. Analytical formulations of environmental contours based on various models are presented and discussed in this study. The design loads are examined by dynamic response analysis of jacket platform. Results suggest that the conditional model is not recommended for use in estimating design loads in sampling locations due to poor fitting results. Independent copula produces conservative design loads and the extreme response obtained using the conditional model are smaller than those determined by copulas. The suitability of a model for contour construction varies with the origin of wave data. This study provides a reference for the design load estimation of jacket structures and offers an alternative procedure to determine the design criteria for offshore structures.     

高层住宅设计及岩土地基承载力分析

高层住宅设计矛盾较多，难度较大，对城市景观影响突出，提高高层住宅设计水平和设计质量十分重要，本文总结了西安公路交通大学高层住宅设计的个性和创意，同时对岩土地基承载力进行了分析。