The scope of this research program was limited to investigate a suitable remedial measure for soil liquefaction and soil improvement by wooden piles, pore pressure generation and settlement behavior of saturated sands. Further investigation in the following topics can contribute to the knowledge of liquefaction behavior and settlement characteristics of soils. From the results of the study, it is observed that the log piling method is more effective than densification method to improve soil density and confining pressure hence it is very effective countermeasure against soil liquefaction. In addition, the following recommendations are made;
1. The conclusions drawn are based on technical feasibility alone. Hence, before large-scale application, financial viability of the applications should be thoroughly checked.
2. Liquefaction is limited to saturated soils. However, soil deposits that are prone to cyclic loadings might not have saturated conditions due to seasonal changes in ground water table or other factors. Therefore, it is desirable to predict cyclic loading behavior of such soils through strain-controlled laboratory testing. This would allow investigating the threshold value for volume change in unsaturated soils as well.
3. In this research, three different scale shaking table tests were performed. In future studies, research should be conducted to confirm that what is the effect of scale of shaking tables on the results.
4. Recently, there are no design codes for design of wooden piles in Japan, so there should be more research on log piles to contribute to make codes for design of wooden piles against liquefaction and for improvement of ground.
5. Log piling is effective countermeasures to mitigate the liquefaction problem and is relatively new technique, so their effectiveness and performance in actual field conditions are needed to be further researched.
The preceding suggestions for future research would contribute significantly to the understanding of using wood against liquefaction, which will potentially lead to improvements in the state-of-the-practice for pile foundation analysis and design under earthquake conditions. This would
further advance the understanding of the use of log piles in the ground as a countermeasure against poor clayey ground and liquefiable sandy ground. This would benefit both design and construction engineers and would likely have significant economic benefits.
List of Publications
By
Saima RIAZ
(By
Type) (theme, journal name, date & year of publication, name of authors inc. yourself) Paper
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Others
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The Effect of Log Piling on Liquefaction, Journal of Geotechnics, JSCE, 2014.Saima Riaz, Atsunori Numata, Kaori Mimura, Hiroaki Ikeda, Toshikazu Hori.
Development of a counter measure against soil liquefaction by using wooden piles, Proceedings of 14th International Summer Symposium in conjunction with JSCE 67th Annual Conference, No.CS12-012, (9), September 2012, Saima Riaz, Masanori Hamada,Atsunori Numata,Hiroshi Motoyama.
Study of Liquefaction Measures by Wooden Piles Comparing Different Types of Soils, Proceedings of the 11th Symposium on Use of Wood for Civil Engineering, (8), August 2012,Saima Riaz,Atsunori Numata, Masanori Hamada.
Overview of large scale shaking table test of log piling for liquefaction mitigation, Proceedings of the 48thJapan National Conference on Geotechnical Engineering, 893(7), July 2013, Atsunori Numata, Shigero Miwa, Kaori Mimura,Yosuke Mizutani, Takumi Murata, Masaho Yoshida, Toshikazu, Hori, Hiroaki Ikeda, Saima Riaz, Tadashi Hara, Akiko Sakabe.
Relation between excess pore water pressure and ground subsidence level on large scale shaking table test of log piling for liquefaction mitigation, Proceedings of the 48th Japan National Conference on Geotechnical Engineering, 894(7), July 2013, Kaori Mimura,Yosuke Mizutani, Atsunori Numata, Shigero Miwa,Takumi Murata, Masaho Yoshida, Toshikazu, Hori, Hiroaki Ikeda, Saima Riaz, Tadashi Hara, Akiko Sakabe.
Large scale shaking table test of log piling for liquefaction mitigation-Relationship between stress and strain in the ground, Proceedings of the 48th Japan National Conference on Geotechnical Engineering, 895(7), July 2013, Murata Takumi, Masaho Yoshida, Shigero Miwa, Atsunori Numata,Kaori Mimura,Yosuke Mizutani, Toshikazu, Hori, Hiroaki Ikeda, Saima Riaz, Tadashi Hara, Akiko Sakabe.
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mitigation, Proceedings of the 48th Japan National Conference on Geotechnical Engineering, 896(7), July 2013, Tadashi Hara, Akiko Sakabe,Atsunori Numata, Shigero Miwa, Kaori Mimura,Yosuke Mizutani, Saima Riaz, Takumi Murata, Masaho Yoshida, Toshikazu, Hori, Hiroaki Ikeda.
Effect of log piling for liquefaction countermeasure on large scale shaking table, Proceedings of the 48th Japan National Conference on Geotechnical Engineering, 897(7), July 2013, Shigero Miwa, Atsunori Numata, Kaori Mimura, Yosuke Mizutani, Saima Riaz, Takumi Murata, Masaho Yoshida, Toshikazu, Hori, Hiroaki Ikeda.
Influence of distance from log on counter measure against liquefaction by log piling, Proceedings of the 12thSymposium on Use of Wood for Civil Engineering, (8), 2013, Ogawa Shusei, Atsunori Numata, Hiroaki Ikeda,Yosuke Mizutani,Akiko Sakabe, Saima Riaz.
Characteristics of soil improved by log piling for liquefaction mitigation, Proceedings of the 12th Symposium on Use of Wood for Civil Engineering, (8), August 2013, Atsunori Numata, Kaori Mimura, Murata Takumi,Tadashi Hara,Saima Riaz, Hiroaki Ikeda, Toshikazu, Hori.
Result of large scale shaking table test of liquefaction countermeasure by log piling, Proceedings of the 12thSymposium on Use of Wood for Civil Engineering, (8), August 2013, Kaori Mimura, Atsunori Numata, Murata Takumi, Hiroaki Ikeda, Saima Riaz, Tadashi Hara, Toshikazu Hori.
Effect of carbon stock by log piling for soil liquefaction mitigation, Proceedings of the 12th Symposium on Use of Wood for Civil Engineering, (8), August 2013, Hiroaki Ikeda, Atsunori Numata,Yosuke Mizutani, Akiko Sakabe, Saima Riaz.
Characteristics of wooden piles used for countermeasure against liquefaction, Proceedings of the 15thInternational Summer Symposium in conjunction with JSCE 68thAnnual Conference, (9), V-034, September 2013, Kaori Mimura, Yosuke Mizutani, Atsunori Numata, Shigero Miwa, Saima Riaz, Tadashi Hara, Akiko Sakabe, Hiroaki Ikeda.