Liquefaction at Moss Landing during Loma Prieta Earthquake

Robertson, P. K.; Wride, C E; Boulanger, Ross W.; Mejia, L. H.; Idriss, I. M.

doi:10.1061/(asce)1090-0241(1999)125:1(91)

Cited by 3 publications

(2 citation statements)

References 2 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The value of rd. the shear stress reduction coefficient, is obtained using the graph proposed by Seed and Idriss in 1999 [11]. rd.…”

Section: Csr =mentioning

confidence: 99%

Liquefaction Potential Analysis of Irrigation Canals at Sidera Area-Sigi Regency

Dinastiyanto,

Hardiyatmo,

Pratiwi

2024

IOP Conf. Ser.: Earth Environ. Sci.

View full text Add to dashboard Cite

An earthquake measuring 7.5 on the Richter scale that occurred in Palu on 28 September 2018 resulted in liquefaction where the soil lost its bearing capacity due to increased pore water pressure. The liquefaction disaster caused great damage to the Gumbasa Irrigation channel, a large part of which is in the alluvial fan area. This study aims to analyze the potential of liquefaction in irrigation canals in the Sidera village area, Sigi Regency. Using SPT (Standard Penetration Test) data from 2 boreholes with a depth of ± 20 m, MASW data, and Earthquake Risk Map. Researchers analyzed with the Seed Simplified Procedure approach, The researchers analyzed the Simplified Procedure method proposed by Seed, which uses a stress-based approach that uses the ratio of soil shear strength (CRR) and earthquake-induced soil shear stress (CSR). The results of the analysis using Peak Ground Acceleration (PGA) of 0.43 and groundwater level variations of -2.85 m (borehole BM 53) and -12.5m (Borehole BM 49) show that liquefaction occurs at depths of 4-8 m (BM 53) and 14-17 m (BM 49). The value of the Liquefaction Potential Index (LPI) increases and indicates a high liquefaction potential below the water table with the highest value of 17.88. The analysis shows that liquefaction is closely related to the shallow water table, soil type, and low N-SPT values. The high liquefaction potential requires prevention methods as a form of treatment.

show abstract

“…The value of rd. the shear stress reduction coefficient, is obtained using the graph proposed by Seed and Idriss in 1999 [11]. rd.…”

Section: Csr =mentioning

confidence: 99%

Liquefaction Potential Analysis of Irrigation Canals at Sidera Area-Sigi Regency

Dinastiyanto,

Hardiyatmo,

Pratiwi

2024

IOP Conf. Ser.: Earth Environ. Sci.

View full text Add to dashboard Cite

show abstract

“…Regarding the procedure of CPT data processing, the efficiency, reliability, accuracy, and limitations of the methodology are discussed in previous publications such as Robertson and Fear (1995), Robertson and Wride (1997, 1998a, 1998b, and Robertson et al (1999. The "correction" factor for grain characteristics (K c ) for flow liquefaction should be studied further in the future, increasing our experience and database on flow failures of siltier deposits.…”

mentioning

confidence: 99%

Undrained shear strength of clean sands to trigger flow liquefaction: Reply

Yoshimine¹,

Robertson²,

Wride³

2001

Can. Geotech. J.

View full text Add to dashboard Cite

The authors would like to thank Dr. Sladen for his valuable discussion on our paper. As pointed out in the discussion paper, there are many assumptions, approximations, and simplifications in the procedure of predicting undrained strength of sands to trigger flow liquefaction proposed in this study, and one should be mindful of these points when applying the methodology in practical use. In this reply paper, we would like to present our comments on the discussion points with additional information about the laboratory and field test data.First, the writer questioned the accuracy and reliability of the triaxial extension and simple shear tests because of the potential errors due to strain nonuniformity and suggested that the results of extension tests shown in Fig. 8 are implausible because the figure indicates sand at a relative density D r as high as 80% may have an undrained strength ratio as low as 0.15. The lower boundary of the undrained strength shown in Fig. 8 is consistent with the triaxial extension tests on Kawagishi-cho sand. To see the test results in more detail, typical stress-strain curves and stress paths from the triaxial extension tests on Kawagishi-cho sand are plotted in Fig. DR1. The highest density of the data points in Fig. 8 is D r = 79%, where actually the sand specimen at a density as high as D r = 90% had some brittleness in triaxial extension with a minimum shear stress ratio around S u /p i ′ = 0.2, as indicated in Fig. DR1. It should be noted that we selected the minimum shear stress as the undrained strength for flow failure from the viewpoint of stability criteria as discussed in the paper. Most of the undrained triaxial extension tests were terminated with necking of the specimens, therefore the ultimate steady states could not be observed. When necking occurred, the apparent mobilized friction angle had decreased and the stress path was bent downwards as shown in Fig. DR1 because the stress components were calculated using the average cross-sectional area of the specimen. Figure DR1 indicates that the stress path from the extension test follows the straight failure line up to the strain level of a few percent to 10% larger than the strain level at quasi-steady state (the minimum stress state), and necking occurred well after the quasi-steady state. Thus it is reasonable to say that measurement of the undrained strength at quasi-steady state was not significantly influenced by strain nonuniformity of the specimen. The simple shear tests described in the paper were performed by means of a hollow cylindrical torsional shear apparatus. We believe that the simple shear test on hollow cylindrical specimen is very reliable because the dimension and shape of the horizontal cross section of the specimen are kept unchanged in the simple shear mode, and therefore there should not be any end restraint due to the friction on the rigid boundaries at the top and bottom of the sample (Yoshimine 1999). Although it is difficult to evaluate the quantitative strain nonuniformity in the specimens, t...

show abstract