The Bearing Characteristic Research Of T-shaped Bidirectional Soil-cement Deep Mixing Pile

Lots of soft clay ground must be improved in engineering construc-tion usually. So foundation treatment technique receive more and more attention by various circles of society. T-shaped bidirectional soil-cement deep mixing pile composite foundation is a new technique which got successful practice in littoral and keep the good development step. In or-der to command and apply it better, indoor and outdoor test and numeri-cal simulation in single and single pile composite foundation were used to analyze and study more its bearing mechanism. The conclusion can improve the technique widely and form the massy theory base, accord-ingly guide the design and construction.The main contents include:1、By consulting a quantity of material, the T-shaped bidirectional soil-cement deep mixing pile and its theory were introduced detailedly and then analysed the specific content and methods of the thesis.2、The thesis analyze the reinforce mechanism of soil-cement by soil-cement unconfined compressive strength test and standard penetra-tion test and then study the relation of pile strength and some parameters such as cement type, cement admixture (W), soil-cement age(d), pile length(L) and so on.3、By doing the field loading test which bury strain pieces by cal-culate their strain volume get the single pile axial force in every cross and additional stress and arranging and analyzing the data, pile load transfer rule and the relation of single pile axial force and additional stress and every parameter were got that include expanding head height(H), diame-ter(D), overloading(P) and then study its bearing mechanism.4、The FLAC3D software of numerical simulation was used to simulate the load and settlement which got the relation between bearing force andL, H, D, the pile axial force and frictional resistance got the re-lation between them and H, up-under pile diameter ratio(R), pile modu-lus(Ep), around soil modulus(Es), bearing stratum modulus(Ec), P, load sharing ratio got relation between it and H, D, P, internal friction angle(φ) and cohesive force(c) of foundation soil.14models were built. By solv-ing and monitoring every model, relation curves were outputted that can help to understand and master more visually the essence of single pile composite foundation.5、Conclusion that got by the tests and simulations will apply the design of parameter of T-shaped bidirectional soil-cement deep mixing pile. Choosing ever parameter reasonably and coordinating relation of every parameter, thus achieve the goals of optimization design, guiding the practice, increasing the benefit.