Muck foam improvement parameter determination method based on shield reasonable tunneling parameter analysis

Abstract

The invention discloses a muck foam improvement parameter determination method based on shield reasonable tunneling parameter analysis, and the method comprises the steps of collecting considered tunneling parameters in a tunneling test section, and carrying out the statistics of the average value, standard deviation, skewness and kurtosis of the considered tunneling parameters in the test section; giving a proper tunneling parameter range in a shield interval range in combination with proper engineering analysis, and accordingly giving a muck water content range, a muck sand content range anda foam injection ratio range which can guarantee normal tunneling of a shield by utilizing linear fitting of a unary function and slump corresponding to the muck water content, the muck sand contentand the foam injection ratio of each ring of a test section; taking the ranges of the three jointly as variables influencing the slump of the muck in the shield tunneling process; solving the change relation of the muck slump along with the muck water content, the foam injection ratio and the muck sand content according to the multivariate linear fitting result, considering the cost factor, and solving the muck water content and foam injection ratio range of the muck reaching the proper slump under the specific stratum according to the range of the corresponding independent variable.

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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