研究目的: 为了降低施工成本,采用分层法对软弱淤泥进行加固,在试验现场具体采用固结-固化复合技术对淤泥进行加固试验研究,使处理后的淤泥满足工程建设所需的特定承载力。对于地表浅层淤泥,采用固化技术进行固化处理,大幅度提升浅层土体强度;对于深层淤泥,采用真空预压技术使淤泥产生排水固结,以提高下卧层软土的强度。
研究结论: (1)固化剂可对浅层淤泥产生较为可观的固化效果,当固化剂掺量为4%~8%时,浅层固化土形成的硬壳层的承载力特征值为164~200 kPa;(2)淤泥仅采用真空预压加固,其承载力特征值仅为40 kPa,采用固结-固化复合技术对淤泥进行分层加固,当固化剂掺量为4%~8%时,双层地基整体的承载力特征值为96~170 kPa,浅层硬壳层对土体承载力提升效果显著;(3)对于双层地基而言,硬壳层具有一定的应力扩散作用,当固化剂掺量为4%时,浅层固化土的应力扩散角可达18.32°,可有效减小软弱下卧层的附加应力;(4)固结-固化复合技术可用于对滨海软土、淤泥回填土地基的大规模加固应用。
Abstract
Research purposes: To save the construction cost, the layered reinforcement method is used to reinforce the soft sludge, and the consolidation and solidification composite technology is adopted to reinforce the sludge in the test site, so that the treated sludge can meet the bearing capacity requirements of the construction. For the shallow surface sludge, the solidification technology is used to greatly improve the strength of the shallow soil. For the deep sludge, the vacuum preloading technology is used to make the sludge consolidated by drainage, so as to improve the bearing capacity of the underlying stratum.
Research conclusions: (1) Solidified agent can generate considerable solidified effect on shallow sludge. When the solidified agent content is 4~8%, the characteristic value of bearing capacity in shallow solidified soil is 164~200 kPa. (2) The characteristic value of bearing capacity of sludge is just 40 kPa as the sludge is reinforced by only vacuum preloading. The consolidation and solidification composite technology is used to strengthen the sludge by layered reinforcement. When the solidified agent content is 4%~8%, the characteristic value of bearing capacity of the two-layered foundation is 96~170 kPa, and the shallow overlying crust has a significant effect on the soil bearing capacity. (3) For the two-layered foundation, the overlying crust has a certain stress diffusion effect. When the solidified agent content is 4%, the stress diffusion angle of the shallow solidified soil is 18.32°, which can effectively reduce the additional stress of the soft underlying stratum. (4) Consolidation and solidification composite technology can be used for large-scale reinforcement of coastal soft soil and sludge backfill soil foundation.
关键词
岩土工程 /
固结固化复合技术 /
分层加固法 /
淤泥 /
应力扩散角
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Key words
geotechnical engineering /
consolidation and solidification composite technology /
layered reinforcement method /
sludge /
stress diffusion angle
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中图分类号：
TU411
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脚注
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基金
温州市基础性科研项目(S2020024)
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