Study On Soft Foundation Treatment Method Of Vacuum And Load-Bearing Combined Compression

With the development of national economy, people are convinced of the importance of infrustrature construction to promote the increasing of economy, such as railway, highway and municipal works engineering, recently decennary, China's infrustration construction have been realized the rapid development, especially on the littoral area where usually featured with the following characteristics: high moisture content, high compressibility, weak osmosis and penetrability, high sensibility, low intensity and unenen/asymmetric depth, etc. thereby, more problem and difficulties will inevitably occurred, and also there are many methods and techonoloty to treat the soft foundation engineeing, and one of the most popular ways is vacuum and load-bearing combined compressions. But just a few researching for soft foundation treatment method of vacuum and load-bearing combined compressions in terms of reinforcement theory, reinforcement result and working procedures, etc. Considering the concrete engineering practice, this paper is mainly concerning about the deeper researching comparatively for mechanism, construction technology and settlement accounting for vacuum and load-bearing pre-compressions testing on soft road foundation and making some useful and feasible researching and practicing conclusion as follows:1. Vacuum and load-bearing combined compressions is featured with double effects of vacuum compression and load-bearing compression, during the period of vacuum-load bearing compression upon harden soft road foundation, vacuum pre-compression obliges the inside of road foundation into the state of loading compression; load-bearing pre-compression forces underground water upgrade from the road foundation hole and crack, under the double roles of vacuum and load-bearing pre-compressions, the underground water falls of road foundation earthworks will accordingly increased, thus underground water drainage speed will accelerated quickly as well as the concretion speed.2. Concretion stress of foundation earthworks will be produced but not shear stress due to the reason of vacuum pre-compression; so vacuum pre-compression can be brought to bear on once only; and earthworks can not be unstable. In one word; to adopt the ways of vacuum and load-bearing combined pre-compression can quickly finish load-bearing pre-compression; efficiently shortening construction period; increasing construction progress and improving social and economic benefit.3. Through the testing site observing data analysis; method of vacuum and load-bearing combined pre-compression to harden railway soft foundation shows not only satisfied hardening effect but also deeper enforcement depth as well as eliminating certain settlement after project completion; and it is proved that this kind of construction technology fits for enforcement and hardening the deep foundation of express railway.