不同含水率土体下强夯加固效果研究

发布时间：2018-04-30 15:28

本文选题：强夯 + 不同含水率　；参考：《中北大学》2017年硕士论文

【摘要】：强夯法作为一种地基处理的方法,因其适用范围广、施工机械简单、加固效果显著、造价相对较低等优点,已经被广泛应用于各种地基处理的工程当中。目前,针对于不同土质条件下强夯加固效果以及加固机理已经进行了深入的研究,通过与施工结合也积累了大量的实际经验,取得了显著的成效。然而,针对于同一种土体,不同含水率情况下的强夯加固效果却少有研究。基于此,本文取用五种不同含水率的土体,通过开展1:8室内模型试验,研究同一能级不同锤重-落距组合下的强夯加固效果,并且与室内击实试验进行对比,最终得到以下结论:1、强夯法与击实试验均存在最优含水率,且强夯法的最优含水率略小于击实试验。2、无论是在哪种含水率的情况下,轻锤高落距的累计夯沉量均小于重锤低落距,且轻锤高落距组合对于土体含水率的敏感性高于重锤低落距。因此,在土体含水率差异较大的地区,采用重锤低落距的施工工艺加固效果更好、更均匀。3、当土体含水率较低的时候,强夯的加固范围主要集中在土体浅层一定深度范围。土体含水率接近强夯最优含水率的时候,相对压密程度随着深度均匀地减小。当土体含水率较高时,在土体浅层范围内出现了明显的压缩不均匀现象。4、得到了在模型试验中的能级下有效加固深度与含水率之间的关系:=Y(36.14-20.3+0.91-ɑ)2??,其中ɑ为组合影响系数。5、通过对夯锤能量反弹比曲线的分析得到:夯锤能量反弹比随着夯击次数的增加逐渐收敛,以此可以作为停夯的一个新参考标准。
[Abstract]:As a kind of foundation treatment method, dynamic compaction method has been widely used in various foundation treatment projects because of its wide application scope, simple construction machinery, remarkable reinforcement effect, relatively low cost and so on. At present, the reinforcement effect and mechanism of dynamic compaction under different soil conditions have been deeply studied, and a great deal of practical experience has been accumulated by combining with construction, and remarkable results have been achieved. However, for the same soil, there is little research on the effect of dynamic compaction under different moisture content. Based on this, five kinds of soil with different moisture content are used in this paper. Through the 1:8 indoor model test, the reinforcement effect of dynamic compaction under the same energy level and different hammer-drop distance combination is studied, and the results are compared with the indoor compaction test. Finally, we get the following conclusion: 1, there is an optimal moisture content in both the dynamic compaction method and the compaction test, and the optimal moisture content of the dynamic compaction method is slightly smaller than that of the compaction test. The accumulative tamping amount of light hammer drop distance is smaller than that of weight hammer drop distance, and the sensitivity of light hammer height drop distance combination to soil moisture content is higher than that of weight hammer drop distance. Therefore, in the area where the moisture content of soil is different, the reinforcement effect is better and more uniform. When the moisture content of soil is low, the reinforcement range of dynamic compaction is mainly in the depth range of shallow soil layer. When the soil moisture content is close to the optimal moisture content of dynamic compaction, the relative compaction degree decreases uniformly with the depth. When the soil moisture content is high, In the shallow layer of soil, there is obvious compression inhomogeneous phenomenon. 4. The relationship between effective reinforcement depth and moisture content under the energy level in model test is obtained. The relationship between effective reinforcement depth and moisture content is obtained. The relation between the effective reinforcement depth and the moisture content is obtained. The coefficient of composite influence is 0. 5, and the energy of ramming hammer is obtained by means of ramming hammer energy. The analysis of rebound ratio curve shows that the energy rebound ratio of rammer converges with the increase of tamping times. This can be used as a new reference standard for stopping tamping.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU472.31

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