Soil Liquefaction Analysis for Earthquakes

soil liquefaction analysis

 

SECTION A

ABSTRACT

One of the major studies of geotechnical engineering is that liquefaction, One of the hazards of the earthquake. The fundamental of the liquefaction in which cyclic loading from earthquake decreased the strength and stiffness of soils and ground behaves like a fluidly for a temporary basis. The reason behind that the water level increased in the soil particles, so due to that the effective stress reduced with time make the soil to behave like fluidly.

For the analysis of the soil liquefaction, the different parameters that are used to get the results of the soil liquefaction, and how the liquefaction impacted the ground soil. The real data of one of the earthquake events will be chosen by the team member, and the borehole data of that earthquake of New Zealand will be used to analysis of liquefaction. The earthquake event will be taken from the software which calls seismosignal (three different earthquake event). Soil analysis and borehole data will be taken from the New Zealand strong motion database.

OVERVIEW

BACKGROUND:

New Zealand is under the seismic unique zone. Which is in the pacific ring of fire, this zone is under volcanism and seismicity alongside the side the points of confinement of the Pacific Ocean. The establishment of the earth liquefaction defenselessness on Christchurch event. This ring verified 40,000 kilometers, which is experienced some country of Asia and America, for instance, Japan, Taiwan, the Philippines, and some various countries of the United States.

On the off chance that we are going nearer to New Zealand in the further figure. That figure demonstrates that; it is set at a bending impact zone among the Pacific Plate and Australian Plate. Among the two plates, Pacific Plate moving legitimately west at 41-47 mm/year inside the region of North island during it is moving west-southwest in the closeness of the South Island at about 37mm/year. In the North Island, the Pacific Plate subducts under the Australian Plate during it superseding the Australian Plate in the South.

Figure 1The ring of fire from Quake and aftershocks rock New Zealand images taken from the google images

The subduction zone in the north make the Hikurangi Trough and Kermadec Trench during the superseding zone in the south made the Puysegur Trench with the Alpine Fault sitting in the middle of the channels. Which is the periodic wonder called as a change strike-slip. The consequence of that, heaps of tremors occur in New Zealand yet some of them are can’t felt by people. In excess of 15,000 tremors are estimated by GNS Science however just 10% of a seismic tremor are felt by people. From this information, it very well may be anticipated that New Zealand may sting in any event one M7 seismic tremor each multiyear and M8 quake at regular intervals.

Figure 2 NEW ZEALAND SUNDUCTION ZONE AND ALPINE FAULT TAKEN FROM GOOGLE IMAGES 

LIQUEFACTION

The phenomenon of liquefaction is one of the most important subjects in Earthquake Engineering and Coastal Engineering. Liquefaction occurs due to the interaction between the pore fluid flow and the dilatancy characteristics of the soil skeleton (Shibata, 1994). The high-water weight misfortune the quality of the soil and change the soil properties. Liquefaction permeability investigation has hips of criteria, for example historical, geological, compositional, state criteria that are talked about in the last report. The high-water weight prompts the soil to experience an inclined toward complete loss of strength. During the earthquake, sustain the water weight in the soil and loos soil retain the water and growth the submerge level at that point soil lost their property of strength, in this manner, the bearing limit is reduced. In the meantime, the loads and the weight of the structure would be the same. Thus, at long last, structure attempts to settle in the ground. Helplessness is one of the criteria to assess the liquefaction by other criteria which are examined previously. The most elevated danger region is moved in place of a man-made landfill, particularly fill that was set numerous decades prior in zones that were once submerged cove floor (Youd, 2001).

The given figure shows the schematic diagram of soil liquefaction during the earthquake.

Figure 3 schematic diagram of soil liquefaction (Council, Tonkin & Taylor Ltd , 2016)

There is another astonishment identified with liquefaction that incorporates stream disappointment, sloping spreading and sand bubble. Flow loose is happening when the soil strengths “dip under the level expected to keep up strength under static condition. Estimation of site-specific building properties of soils and site conditions is a key viewpoint in the assessment of liquefaction potential at a given site. At first, screening methodology dependent on geographical criteria and soil order are frequently embraced to analyze whether the soil at the site may be susceptible to liquefaction or not. It is likewise important that past liquefaction doesn’t improve soil liquefaction protection from future occasions (Seed, 1971)

liquefaction triggering

The intensity and duration of earthquake shaking required to cause (trigger) liquefaction of susceptible soils, varies depending on the density and fines content of the soil. The likelihood of earthquake shaking triggering liquefaction is assessed by considering: The local seismic hazard, The likelihood (return period) of earthquakes of various duration (magnitude) and intensity (peak ground acceleration, PGA), Field penetration tests (CPT, and SPT – Standard Penetration Tests) and fines content results for the soil, and available empirical relationships between these results and the magnitude and PGA to trigger liquefaction.

Problem faced during project

Well genuinely saying, I and my project mate has not too much familiar with the new software but we like challenges that’s why we are working on the soil liquefaction analysis under different NZ earthquake event .To get the data of the liquefaction analysis like soil classification, the specification of the earthquake event, and the borehole data of the earthquake station.  And to get the borehole data it is very time-consuming process and we both need to get different seismosignal and borehole data.  

3 PROJECT SCOPE

SCOPE OF THE PROJECT

The project will talk about the different parameters that will be used to define the soil liquefaction and the three different earthquake events of the New Zealand. With the help of the collected soil data, possible liquefaction of the site will be evaluated to define appropriate to soil destruction of liquefaction. After that with the help of the several methodologies, the NOVOLIQ software will help to define the different parameters and methodology to estimate the soil liquefaction.

Work brake down structure

The given below WBS shows the schedule of the soil liquefaction analysis. The work brake down structure shows the proposed work that will be done in this project. There will be some chances in the WBS if something happens, for instance, to get the data of the earthquake event or in the research of any stages, but my group is confident that we will do this project accordingly WBS.

 1                     2                        3                     4

Parametrical analysis for soil liquefaction

Data

Research                                      

calculation

Brainstorming

                                          

Collect earthquake data

Discussion of topic

Literature review

calculate

Project proposal

Det. Max earthquake

Narrow downs topics

Collect soil data

presentation

Estimation distance from fault

Structure of project proposal

Explanation of software

Borehole data

 

NOVOLIQ

Finalize topic

Estimate site topography

SEISMOSIGNAL

Work to be included in topic

 

            5                         6                          7

Data output

Output analysis

Compare output of all site

Calculation and recommendation

Final

Data output

Final writeup

Output analysis

Recommendation

Prepare presentation

Compare output of all site

Discussion of result

result

Create poster

Future plan

4.Project Methodology and Requirements

4.1. Project Methodology

The methodology taken from the module 3 of the ministry of business, innovation and employment (MBIE), which has a series on geotechnical earthquake engineering practice will be used in this project for the guidance of the parametric analysis. The given figure tells the methodology of this project and the software which will be used in this project called NOVOLIQ and SEISMOSIGNAL.

Figure 4 : Factors to consider in liquefaction vulnerability assessment (IDENTIFICATION, ASSENSMENT AND MITIGATION OF LIQUEFACTION HAZARD, 2016)

Figure 5 Factors to consider in liquefaction vulnerability assessment (Martin, 2016), (IDENTIFICATION, ASSENSMENT AND MITIGATION OF LIQUEFACTION HAZARD, 2016)

4.2 Project requirements

4.2.1. Data and Equipment

In this project, it is believing that soil data in borehole logs with SPT values will be needed for the parametric analysis. After that the soil profile and shear wave velocity will be calculated from the borehole data with the help of ProShake 2.0.

For parametric analysis of this project, soil details in borehole logs with SPT values are necessary. The geological conditions at sites are conjectured based on nearby SPT. The calculation of the soil profile and shear wave velocity are done from borehole logs information with help of the ProShake2.0 software (EducationPro civil system, 2018). We have evaluated the hazard of soil liquefaction happening at the site by means of the subsurface information from the collated CPT surveys and the methodology industrialized. The earthquake history data of the different location is taken from the New Zealand strong-motion Database (Van Houtte , Bannister, Holden, Bourguignon, & McVerry, 2017). Each member of this project team has evaluated the different location of the earthquake data and borehole logs details. This calculation delivers the value of the moment magnitude M_w and other related details are also computed.

For an evaluation of this project, there is no need for the equipment. However, it was very difficult to gather the information related to earthquake location such soil profile, borehole log data and to perform the laboratory test which is time consumed.

4.2.2. Software

In this project, there will be many software which we have to run in this study. The software like, NOVOLIQ for the analysis of liquefaction of the earthquake event. And, the Seismosignal will be used for the earthquake data and the acceleration.

There are mainly three software used for the project. The ProShake is used for the soil analysis from NovoLIQ. Seismosignal is employed for reviewing and assessing of earthquake data. NovoLIQ software is engaged to analysis of liquefaction weakness of the site.

Discuss possible topics	2
Discussion of How narrow down the list of topics	3
Discuss structure of project proposal	2
Finalize topic	2
Discuss work to be included in the project	3
Literature review	15
Prepare proposal	3
Proposal defense	4
Collect earthquake data	5
Collect soil data and borehole data	5
Encode earthquake and soil data	6
Seismosignal processing	8
Determine maximum earthquake acceleration	9
Determine earthquake magnitude	10
Earthquake distance from Nz fault	12
Estimate site topography	13
Output analysis	14
Compare output of all sites	15
Discussion of results	15
Write final project paper	16
Create poster of the projects	17

Following table.1 schedule of the project plan.

Bibliography

• Dr.Frankie, K. (Director). (2017). CEEN 545 – Lecture 23 – Soil Liquefaction (Part 1) [Motion Picture]. Retrieved from https://www.youtube.com/watch?v=Id3ktqZDv8A&t=790s
• EducationPro civil system. (2018). Geosysta Ltd. Retrieved from GeotechPedia: https://geotechpedia.com/Publication/Category
• google images . (n.d.). Retrieved from https://www.google.com/search?tbm=isch&sa=1&ei=iKJMXYaZDKXgz7sPire70AE&q=The+pacific+ring+of+fire+of+new+zealand&oq=The+pacific+ring+of+fire+of+new+zealand
• (2016). IDENTIFICATION, ASSENSMENT AND MITIGATION OF LIQUEFACTION HAZARD. Retrieved from https://www.building.govt.nz/assets/Uploads/building-code-compliance/b-stability/b1-structure/geotechnical-guidelines/module-3-liquefaction-hazards.pdf
• Lees, J., van, S. B., & Wentz, F. J. (2015). Liquefaction Susceptibility and Fines Content Correlations of Christchurch Soils. 6th International Conference on Earthquake Geotechnical Engineering (pp. 1-9). Christchurch: ICEGE. Retrieved from https://www.issmge.org/uploads/publications/59/60/578.00_Lees.pdf
• Martin, G. (2016, May). NEW ZEALAND GEOTECHNICAL SOCITY . Retrieved from Ministry of Business, Innovation and Employment: https://www.building.govt.nz/assets/Uploads/building-code-compliance/b-stability/b1-structure/geotechnical-guidelines/module-3-liquefaction-hazards.pdf
• MBIE. (2016). Earthquake geotechnical engineering practice. Retrieved from Ministry of Business, Innovation and Employment: https://www.building.govt.nz/assets/Uploads/building-code-compliance/b-stability/b1-structure/geotechnical-guidelines/module-3-liquefaction-hazards.pdf
• Seed, H. B. (1971). TRID. SIMPLIFIED PROCEDURE FOR EVALUATING SOIL LIQUEFACTION POTENTIAL. Retrieved from https://trid.trb.org/view/127844
• Shibata, T. (1994). springer link. FEM-FDM coupled liquefaction analysis of a porous soil using an elasto-plastic model. Retrieved from https://link.springer.com/article/10.1007/BF00853951
• USGS. (2010). Liquefaction Susceptibility. Retrieved from Earthquake.usgs.gov: https://earthquake.usgs.gov/learn/topics/geologicmaps/liquefaction.php
• Van Houtte , C., Bannister, S., Holden, C., Bourguignon, S., & McVerry, G. (2017). New Zealand Strong-Motion Database. Retrieved from Geonet strong motion site: https://www.geonet.org.nz/data/supplementary/nzsmdb
• Youd, T. L. (2001). ASCE Library header logo. Journal of Geotechnical and Geoenvironmental Engineering. Retrieved from https://ascelibrary.org/doi/abs/10.1061/(ASCE)1090-0241(2001)127:4(297)