huangyhg

design and construction of shoring for deep basements
presently i would say the satandard practice where feasible is to use anchors to the ground of walls previously made with the temporary help of bentonite. as you deepen, you anchor in the required amount. then, if yor build fllors able to sustain the compression of the earth against the walls you may (and sometimes is required) release the (then) temporary anchors.
however ordinance is adversary in downtown to this, since there are standing facilities that may result damaged.
then piles as the walls may be done before, and instead of any unreliable buttressing or complicated in compression scaffolding and structural members (i have seen ugly 20 m span or so near horizontal arches helping to stand earth pressure) you may build the underground floors on the piles and walls from top (surface) down (to deepest slab). this way you are using the final structure to hold the push inwards your underground levels.
pti has a publication on underground anchors
recommendations for prestressed rock and soil anchorspti
another interesting is
recomendaciones para el proyecto, construcción y control de anclajes al terreno h.p. 8-96
atep / ietcc / ciccp
look also
deep excavations
malcom puller
the south african institution of civil engineering (saice) has a code of practice "lateral support of surface excavations" isbn 0-620-13790-8
it is not on the internet as far as i know.
not an easy task in general. much would depend on the type of soil and location and type of the structures on the adjacent lot(s).
there's much variation in the need, depending upon the soil condition. normally the walls are executed by batches 2 to 4 m wide, these designed to be autostable whilst in the foundation work. it is rare to use bentonite helped cantilever trench walls for this depth, but may be required or convenient if the plot is big and water is some real hassle.
kevin shang (visitor)12 apr 02 19:29
i have done some projects like this under the mud condition, in me opinion, you must to be have abilities as bellow:
1.understanding geomachnics.
2.proficiency in structural analysis and design.
3.you well knowen all about the basement and above
structur.
4. you can estimate and compare the coastyour shoring system.
5.invastigation the exesisting building around excavition.

__________________
借用达朗贝尔的名言：前进吧，你会得到信心!
[url="http://www.dimcax.com"]几何尺寸与公差标准[/url]