Classification Method of Sandy Pebble Strata Based on Shield Engineering Characteristics
In response to the difficulty of long-distance and efficient shield tunneling in sandy pebble strata,this paper summarizes the common engineering problems of shield tunneling in sandy pebble strata and proposes that particle size,fine particle content,water pressure,and wear performance are the characteristic factors that restrict efficient shield tunneling;it also provides characteristic indicators,indicator determination methods,and indicator quantification intervals for each factor.Sandy pebble strata were classified based on the indicator quantification interval.According to different strata categories,the reasonable shield tunneling schemes is matched,and the applicability of the strata classification method was verified using a shield tunneling example in sand pebble strata under combined indicators.The research results indicate that sandy pebble strata can be divided into transportable and non-transportable strata according to the maximum particle size dmax and maximum discharge capacity d of the screw conveyor dp;according to the proportion of total strata in the same interval of fine-grained lens layer λ,the sandy pebble strata can be divided into high viscosity,low permeability,and low viscosity,high permeability strata;according to the height of groundwater level hw and limit water level height h0,the sandy pebble strata can be divided into high water level and low water level strata;Based on the equivalent quartz content Qe,the sandy pebble strata can be classified into high-and low-abrasive strata.This classification method provides theoretical guidance and technical support for the design and construction of shield tunneling in sandy pebble strata.
NETL
NSTL
万方数据
维普
