电厂循环管淤泥质地基过大沉降加固效果研究

Study on Reinforcement Effect of Muddy Soil Foundation over Large Sedimentation in Power Plant

海相淤泥质土具有含水量高、压缩性强及承载力低等特性,工程实践地基处治后服役期一旦出现沉降过大现象,不仅治理费用昂贵且二次加固技术要求较高。依托印度尼西亚雅加达湾北部龙湾3×315 MW燃煤电厂循环管地基工程为背景,在分析循环管地基原"真空预压+竹桩"处治措施的基础上,借助实测数据从设计、施工及管理等方面阐述了地基过大沉降的原因;考虑加固中循环管保持正常工作因素,提出"循环管两侧高压双管旋喷桩+循环管道下部双液注浆"二次集成加固方案。综合测试和数值计算结果可知,二次加固方案实施后循环管地基沉降得到控制,测试50 d(趋于稳定)累计沉降约为22 mm;计算预测30年累计沉降约为48 mm(5 cm以内),沉降速率小于0.01 mm/d;实测和计算均验证加固控制效果较好。研究成果能为类似工程实践提供理论参考。

The marine muddy soil has the characteristics of high water content,strong compressibility and low bearing capacity.After the engineering practice and the service period,the sedimentation is too large,which is expensive and the secondary reinforcement technology is high.Based on the analysis of the'vacuum preloading and bamboo pile'treatment measures of circulating pipe foundation in the north of Jakarta Bay,Indonesia,the design of the measured data is from the aspects of design,construction and management.This paper expounds the reason of the large settlement of the foundation.Considering the normal working factors of the circulating pipe in the reinforcement,the author puts forward the second integrated reinforcement scheme of the double-liquid grouting pile on the two sides of the circulating pipe.According to the results of comprehensive test and numerical calculation,it can be seen that the settlement of the recirculating pipe is controlled after the second reinforcement scheme is carried out.The cumulative settlement is about 22 mm for 50 days(stable).The cumulative sedimentation is about 48 mm(within 5 cm)and the settling rate is less than 0.01 mm/Day;measured value and calculated value to verify the reinforcement control effect are better.The research results can provide reference data for similar engineering practices.