Research Of A New Soil Improvement For EPB Shield

With the rapid development of city track traffic construction，EPBS(EarthPressure Balanced Shield tunneling) is widely used by its unique advantages.Muck conditioning technology in EPBS, which is one of the key technology, hasbeen paid more and more attention. There are two kinds of muck conditioningagents, one is foam and the other one is slurry, and each have their own mostappropriate layer. But in the larger particle size of gravel stratum, slurry is widelyused. But what is used in construction site is pure betonies slurry. In order toimprove the viscosity of slurries, most increase the dosage of betonies, which led theslurry consistency coefficient is too large, reopen pump becoming difficult,increasing the slurry cost and so on. In order to improve these defects, with theBeijing subway line ten backgrounds, this paper through theoretical analysis,laboratory tests and field test methods, according to the engineering characteristicsof sand and gravel stratum, optimized the best slurry preparation program byorthogonal test. And through the field test research on shield parameters, determinedthe useful of new slurry in EPBS. The main research results of this paper is asfollows:(1) Optimized the best additive which has the best Improve performance toslurry by indoor test and determined it’s optimum adding amount;(2) Optimized the best slurry preparation program by orthogonal test ondifferent scheme of comprehensive performance analysis of slurry;(3) Evaluation of novel slurry amelioration effects through comparison andanalysis of the two kinds of slurry ‘s improvement effects in pebble/round gravel and sand by Indoor simulation test;(4) Determined the new slurry’s practical application through analysising ofshield parameters when it is used in EPBS and comparing with the commonslurry by field test.By Combining the theory with practice, indoor simulation experiment and fieldtest, this topic determined a novel slurry preparation plan and practicality. And make a cost comparison with site slurry. It may have certain guiding significance to thelater new slurry research.