VanNuysDave
Geotechnical
- Mar 5, 2003
- 9
As usual - thanks to everyone ahead of time.
The subject is a question that is becoming more complex and more challenging for us folks in Seismic Zone 4 and more financially cripling for those who build using our analyses.
When we have projects that are subject to deep liquefaction and large magnitudes of lateral spreading, the answer is usually ground modification, encapsulation or 'big' piles (usally driven when groundwater is high). If the axial load (including the downdrag) allows for piles, most developers prefer the finite cost of a driven pile rather than the sometimes 'extras' associated with ground modification techniques.
My request is for your thoughts on the most practical, realistic analyses and evaluation of lateral spreading loads on large groups of piles - what is the most accurate method of assessing the transfer of the lateral soil load from one pile to the other and is there a point within a large group of piles below a structure when the piles actually mitigate the lateral spreading and disipate the load so there is almost no moment applied to the interior piles of the group other than through the structure (and those consequences)?
Is there some adeptation of L Pile or the strain wedge model (DFSAP)or stress/ strain finite element to model this condition ?(if so - which program is the most adaptable to this case).
The subject is a question that is becoming more complex and more challenging for us folks in Seismic Zone 4 and more financially cripling for those who build using our analyses.
When we have projects that are subject to deep liquefaction and large magnitudes of lateral spreading, the answer is usually ground modification, encapsulation or 'big' piles (usally driven when groundwater is high). If the axial load (including the downdrag) allows for piles, most developers prefer the finite cost of a driven pile rather than the sometimes 'extras' associated with ground modification techniques.
My request is for your thoughts on the most practical, realistic analyses and evaluation of lateral spreading loads on large groups of piles - what is the most accurate method of assessing the transfer of the lateral soil load from one pile to the other and is there a point within a large group of piles below a structure when the piles actually mitigate the lateral spreading and disipate the load so there is almost no moment applied to the interior piles of the group other than through the structure (and those consequences)?
Is there some adeptation of L Pile or the strain wedge model (DFSAP)or stress/ strain finite element to model this condition ?(if so - which program is the most adaptable to this case).