A Method for Determination of Muck Foam Improvement Parameters Based on Analysis of Reasonable Tunneling Parameters of Shield Tunneling

Abstract

The invention discloses a method for determining the improvement parameters of slag foam based on the analysis of reasonable excavation parameters of shield tunneling. The kurtosis, combined with appropriate engineering analysis, gives the appropriate range of excavation parameters within the shield tunneling interval. Based on this, the linear fitting of the univariate function is used, combined with the moisture content of each ring of slag, the sand content of the slag, and the foam injection ratio in the test section. The slump of the slag is given, and the range of the moisture content of the slag, the sand content of the slag, and the foam injection ratio that can ensure the normal excavation of the shield is given. The three ranges are taken together as the variables affecting the slump of the muck in the process of shield tunneling. Then, according to the multivariate linear fitting results, the relationship between the slump of the slag and the water content of the slag, the injection ratio of foam and the sand content of the slag is solved, considering the cost factor, and according to the range of the corresponding independent variables, the slag can reach the slag under a specific stratum. Range of soil moisture content and foam injection ratio suitable for slump.

Description

technical field [0001] The invention relates to the technical field of shield tunneling, in particular to a method for determining parameters for improvement of muck foam based on the analysis of reasonable shield tunneling parameters. Background technique [0002] As one of the important construction methods for tunnel excavation in soft ground, the earth pressure balance shield method is widely used in the construction of subways in major cities at home and abroad. The improvement of muck is an important guarantee for the smooth excavation of earth pressure balance shield tunneling. During the excavation of shield tunneling, the muck produced should have good flow plasticity, good impermeability, suitable compressibility, and low adhesion And smaller internal friction angle, for this reason, foam is often used to improve the properties of muck. However, at this stage, due to the lack of relevant quantitative guidance for the selection of parameters for muck foam improveme...

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Problems solved by technology

[0004] Peila ("Using the slump test to assess the behavior of conditioned soil for EPB tunneling." Environmental & Engineering Geoscience 15.3 (2009): 167-174.) and others used the slump test to evaluate the plasticity of the foam-improved soil, and used this To characterize whether the muck is well improved by foam, it is proposed that when the slump range is 10cm-20cm, the muck is well improved, which provides a certain reference for the evaluation of the improvement state of the foam improved muck and the selection of improvement parameters, but on-site The slump test is limited by the small space of the shield machine and other test conditions, and it is often impossible to "follow up" the slump of the muck during the shield tunneling process. Secondly, directly test the slump of the muck It is often a method of "post-evaluation", which can only evaluate the improvement of single-ring muck soil, and cannot guide the selection of foam improvement parameters well.

At the same time, the reasonable slump range of 10cm-20cm given by Peila is not universal. When the shield tunnels in some clay-bearing strata, controlling the slump range to 5cm-10cm can ensure the shield tunneling. Efficient excavation, if the slump is too large, it is easy to cause the screw machine to spew and induce safety accidents

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