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建筑物在荷载作用下,为了保证安全和正常使用,基础首先必须有一定的稳定性,同时宅的变位亦不能超出一定的范围。对一般以垂直荷载为主的公民用建筑物,在土质地基中基 础的稳定以地基的塑性区域不超过一定深度来保证[1]。实际上由于基底应力的重分布,地基的塑性区域不易确定,只是在加荷作用下基底下逐渐形成压密楔,而在两侧反复调整塑流与稳定,此时土的蠕变性能对稳定起着很重要的因素。当然形成压密楔后的地基极限稳定性,仍须取决于基础埋深所产生的边载土的条件。 上述情况均经模型试验所证实,并归纳出相应的稳定分析计算公式(2)。同时基础上仅有垂直荷载的性质单纯,易于根据建筑物的重要性和地基土的蠕变性能,确定出相应的安全系数,使不致发生过多的塑性变形。 但是对兼有水平荷载的一般水工建筑物而言,例如挡水挡土建筑物,在稳定破坏以前就很难说基底下一定有压密楔的存在。同时在某个使用荷载作用下,继续增加垂直荷载、水平荷载或相应倾角的倾斜荷载,都足以产生极限稳定的条件,而且在这个过程中基础的水平变位很难确定,迄今尚未有合理的计算方法。因此在这种情况下,从理论上分析出符合设计原则的稳定安全系数,就更为复杂。 目前关于水平荷载作用下地基稳定的理论或半理?
Under the action of the load, in order to ensure safety and normal use, the foundation must first have a certain degree of stability. At the same time, the house’s displacement must not exceed a certain range. For civil buildings, which are generally based on vertical loads, the foundation’s stability in soil foundations is guaranteed by the plastic zone of the foundation not exceeding a certain depth [1]. In fact, due to the redistribution of the stress of the basement, the plastic zone of the foundation is not easily determined, but the compaction wedge is gradually formed under the load and the plastic flow and stability are repeatedly adjusted on both sides. At this time, the creep performance of the soil is stable. Plays an important factor. Of course, the ultimate stability of the foundation after forming the compaction wedge must still depend on the conditions of the side load soil generated by the foundation depth. The above conditions were confirmed by model tests and the corresponding stability analysis formula (2) was concluded. At the same time, based on the fact that only the vertical load is simple, it is easy to determine the corresponding safety factor according to the importance of the building and the creep performance of the foundation soil, so that no excessive plastic deformation occurs. However, for general hydraulic structures with horizontal loads, such as retaining buildings, it is difficult to say that there must be compact wedges under the basement before stabilizing the damage. At the same time under a certain use of load, continue to increase the vertical load, horizontal load or inclined load of the corresponding inclination angle, are enough to produce the condition of limit stability, and in this process, the horizontal displacement of the foundation is difficult to determine, so far there is no reasonable Calculation method. Therefore, in this case, it is more complicated to theoretically analyze the stable safety factor that meets the design principles. At present, the theory or half-mechanism of foundation stability under the action of horizontal loads?