A monitoring method for the effect of foundation pit rotary grouting piles on elevated high-speed railway construction

Abstract

The invention discloses a method for monitoring the construction effect of a jet grouting pile of a foundation ditch under an elevated high-speed railway line. The problem of being unscientific, unsystematic and insufficient in monitoring the influence of the process of high pressure jet grouting pile forming under the prior art on the foundation of an elevated high-speed railway bridge is solved,and the method for monitoring the construction effect of the jet grouting pile of the foundation ditch under the elevated high-speed railway line has the beneficial effects of ensuring the safety work of the elevated high-speed railway bridge are achieved. According to the technical scheme, the method for monitoring the construction effect of the jet grouting pile of the foundation ditch on the elevated high-speed railway comprises the following steps that (1) according to a construction plan of the high pressure jet grouting pile, a monitoring scheme of monitoring the change of a stress field and a displacement field of surrounding soil in the process of monitoring pile formation is formulated; (2) monitoring is carried out according to the monitoring plan determined in the step (1); (3)monitoring data are organized to analyze the influence law of grouting pressure on the displacement field and the stress field of the surrounding soil in the process of high pressure jet grouting pile forming, namely, the construction effect of the high pressure jet grouting pile, and the influence of the construction effect of the high pressure jet grouting pile on the elevated high-speed railway foundation is determined; and (4) according to the analysis, the construction effect of the high pressure jet grouting pile can guide the following construction.

Description

technical field [0001] The invention relates to the field of support, in particular to a method for monitoring the construction effect of foundation pit rotary grouting piles on elevated high-speed railways. Background technique [0002] High-speed rail stations are generally located outside the city, such as Jinan West Railway Station, Nanjing South Railway Station and so on. Most high-speed rail lines have elevated lines. With the extension of urban municipal roads, some municipal facilities such as main roads and underground pipelines often need to pass through elevated high-speed rail lines and form foundation pits under elevated high-speed rail lines. At present, the national standard "Technical Specifications for Building Foundation Pit Support Monitoring (GB50597)" has been used as specific guidance for foundation pit monitoring, but the specification lacks specific monitoring and requirements for the construction effect of support structures. [0003] Municipal road...

AI Technical Summary

Problems solved by technology

During the pile formation process of high-pressure rotary grouting piles, huge injection pressure will be generated on the surrounding soil, and the foundation pit under the elevated high-speed rail line is often very close to the foundation of the elevated high-speed rail, so the stress field of the surrounding soil during the high-pressure rotary grouting piles will be affected. The change will greatly affect the stress state of the original elevated high-speed rail bridge foundation and cause it to deform, affecting the traffic safety of the high-speed rail line

At present, neither the current foundation pit monitoring specifications nor the high-speed railway line technical specifications have relevant monitoring procedures for the construction of rotary jetting piles on the surrounding elevated high-speed rail foundations. The monitoring methods commonly used in foundation pit excavation are used in the construction of rotary jetting piles. Effect monitoring has the following defects: ①The monitoring limited to displacement ignores the influence of stress field changes caused by grouting pressure; ②The monitoring of displacement is limited to the elevated high-speed rail foundation, which cannot give full play to the role of monitoring; ③It is difficult to apply common monitoring methods, resulting in a lack of monitoring system sex, scientific

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