An experimental study of reinforcement of the Wenzhou sludge based on the consolidation and solidification composite technology
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摘要:
为了对软弱淤泥土进行加固，使之满足工程建设所需的一定承载力，在试验基地采用固结-固化复合技术对淤泥进行加固研究。试验时，将一定厚度淤泥分为浅层固化加固层和深层固结加固层；浅层（≤1 m）淤泥采用固化技术进行加固，使之形成高强度硬壳层；对于深层（＞1 m）淤泥，采用真空预压技术进行加固，以提高深层淤泥的承载力并控制加固土体的后期沉降量。试验结果表明，当固化剂掺量为0.6%～5.0%时，浅层固化淤泥承载力特征值在109～330 kPa；固结-固化复合技术对土体加固效果突出，分层加固土体整体的承载力特征值在89～230 kPa；浅层淤泥经过固化处理后，土体强度较高，对地表荷载起到了明显的扩散作用，有效地减小了地表荷载在下卧层土体中产生的附加应力；多数试验单元浅层固化土的应力扩散角在19.474°～26.303°之间。
Abstract:In order to reinforce the soft sludge and makes it meet the certain bearing capacity of the engineering construction, the consolidation and solidification composite technology is used to reinforce the sludge in the field site. During the test, a certain thickness of sludge is divided into a shallow solidification layer and a deep consolidation layer. The solidification technology is used to reinforce the shallow (≤1 m) sludge so as to form a high-strength overlying crust. For the deep (>1 m) sludge, the vacuum preloading technology is used to improve the bearing capacity of the deep sludge and control the later settlement of the reinforced soil. The experimental results show that the characteristic value of the shallow solidified soil bearing capacity ranges from 109 to 330 kPa when the dosage of solidified agent is 0.6%～5.0%. The consolidation and solidification composite technology has a prominent effect on the reinforcement of the sludge and the characteristic value of the overall bearing capacity of the layered reinforced soil varies between 89 and 230 kPa. After the solidification treatment of the shallow sludge, the soil strength is higher, which can generate an obvious diffusion effect on the surface load and effectively reduces the additional stress in the underlying layer caused by the surface load. The stress diffusion angle of shallow solidified soil in most test units varies between 19.474° and 26.303° in this experiment.
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表 1 淤泥的基本物理指标
Table 1. Basic physical properties of sludge
含水率
/%黏粒含量
/%液限
/%塑限
/%有机质含量
/%孔隙比 相对密度 66.3 49.4 52.5 27.5 3.4 1.821 2.67 
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表 2 固化剂的化学成分及粒径范围
Table 2. Chemical compositions and particle size range of the solidified agent
化学成分/% 粒径分布/% CaO MgO CO2 SO3 ≤100μm ≤200μm ≤2mm 85.21 2.11 0.31 0.04 70.21 88.62 100
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表 3 各试验单元固化剂掺入比
Table 3. Mixing ratio of the curing agent in each test unit
编号 GH-1 GH-2 GH-3 GH-4 GH-5 GH-6 固化剂掺量/% 0.0 0.6 1.0 2.0 3.0 5.0
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表 4 土体的平板荷载试验数据汇总（0.707 m×0.707 m）
Table 4. Summary of the plate loading test data of soil
区域 固化剂
掺量/%加载时土体
极限荷载/kPa土体极限
荷载/kPa土体承载力
特征值/kPa破坏形式 GH-1 0.0 80 80 40 冲剪破坏 GH-2 0.6 180 178 89 冲剪破坏 GH-3 1.0 320 320 133 冲剪破坏 GH-4 2.0 360 360 168 冲剪破坏 GH-5 3.0 380 380 190 冲剪破坏 GH-6 5.0 460 460 230 冲剪破坏
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表 5 双层地基模型数据汇总
Table 5. Data summary of the double-layer foundation model
区域 固化剂
掺量/%第一层土体
变形模量E 01/MPa第二层土体
变形模量E02/MPa模量
比扩散角
θ/（°）GH-1 0.0 4.0 4.0 1.0 / GH-2 0.6 8.0 4.0 2.0 10.027 GH-3 1.0 9.2 4.0 2.3 19.474 GH-4 2.0 11.3 4.0 2.8 21.628 GH-5 3.0 20.6 4.0 5.2 22.638 GH-6 5.0 34.4 4.0 8.6 26.303
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