Mohammad Siroos Pakbaz

Mohammad Siroos Pakbaz
Shahid Chamran University of Ahvaz | scu · Department of Civil Engineering (Ahvaz)

PhD Geotechnical Engineering University of Illinois at Urbana -Champaign

About

44
Publications
9,860
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
467
Citations

Publications

Publications (44)
Article
Full-text available
Microbial induced calcite precipitation (MICP) technology in recent decade has been introduced to geotechnical engineering society as a mean for soil improvement. In this regard stimulation of indigenous aerobic and anaerobic bacteria is an alternative to bioaugmentation process in which bacteria are added to the soil. The aim of this study was to...
Article
Full-text available
Pile groups are commonly used in geotechnical engineering construction; thus, understanding the response of a pile group located near a soil slope is of practical value to structural design. The purpose of this study was to analyze the response of pile groups located in soil slopes with regard to axial load capacity, settlement, and horizontal disp...
Article
Full-text available
This study presents the results of an extensive laboratory model tests for lateral dynamic compaction on dry sand on the slope. At lateral dynamic compaction, the tamper strikes the surface of the sloping layer vertically in a circular path. The set consists of a steel box containing soil and a cylindrical tamper with a circular flat cross section...
Article
Full-text available
Dynamic compaction is a low-cost soil improvement method that is most commonly applied in sandy soils. Free fall compaction is not applicable to compact the soil in the slope, but it is possible to perform lateral dynamic compaction in the slope. In this method, the angle of impact of the tamper with the inclined surface is vertical. In this dynami...
Article
Full-text available
Dynamic triaxial test is one of the most common geotechnical laboratory tests to measure the dynamic properties of soils. Therefore, dynamic triaxial devices have been developed to increase the accuracy of measuring dynamic soil parameters as well as to automate the test steps. However, this matter requires complex design and modern instruments tha...
Article
Full-text available
This paper presents the applicability of Reduced Length Buckling-Restrained Braces (RLBRBs) in combination with strut elements in deep excavations. Strut members are used as part of the lateral load resisting system. By proposing a new type of RLBRB section, the advantages of RLBRBs are demonstrated in dynamic soft soil-structure interactions. A nu...
Article
Full-text available
This research investigates the mechanical behavior of artificially cemented sandy soils formed by lime alkali activation of natural zeolite under saturation settings. In order to verify the bar capability of cemented sands with this new method, an analysis of the undrained shear strength of the soil with pore water pressure ratio measurements was p...
Article
Full-text available
In this research, we investigated the abilities of three different concentration of sugarcane molasses as a carbon source to stimulate indigenous bacterial growth in different classes of soil, namely poorly graded sand (SP), silty sand (SM), and clayey sand (SC) (according to the Unified classification system). A total of 7, 10, and 15 days after t...
Article
Microbially induced calcite precipitation (MICP) is a bioinspired improvement method of granular soils, as it can significantly affect their engineering characteristics. In fact, calcite nanoparticles produced through MICP increase the angle of internal friction and cohesion intercept of granular soils. As a consequence, the shear strength values o...
Article
Full-text available
Microbiologically induced calcite precipitation (MICP) is a biogeochemical process in which calcite is precipitated within the soil environment due to microorganism activity. Because soil properties are highly influenced by the microorganism population, soil properties can be improved by stimulating microorganisms in the soil with suitable material...
Chapter
Stabilization and improvement of soil quality in terms of increased compressive strength and reduced settlement and other geotechnical parameters have been long investigated. Various studies have examined the effects of different types and amounts of stabilizers on different soils. In most of these studies, fine-grained soils have been tested at op...
Article
Recent studies have shown that the use of biostimulation is an effective technique to eliminate the environmental side effects of traditional soil improvement methods. The use of indigenous bacteria of soil is a new method through which indigenous bacteria produce carbonate calcium by their urease activity. Stimulation of soil indigenous bacteria w...
Article
Full-text available
Today, the increased need for construction in congested urban areas has necessitated construction of tall and massive structures. In these cases, design engineers have the option of excavation and digging of undisturbed and fresh spaces under the ground. Due to the presence of urban structures and public facilities adjacent to the excavation sites,...
Article
Full-text available
A new method for soil stabilization known as microbial-induced calcite precipitation (MICP) has been the focus of research in this area during the last decade. In this method, the reaction of microorganisms in the presence of urea and calcium chloride is used to produce calcite. Despite the large numbers of bacteria in soil, Sporobacillus pasteurii...
Article
Full-text available
The purpose of this study was evaluation of magnitude and time rate of swelling pressure due to the presence of gypsum in clayey soils stabilized with lime. 3,5 and 10 % of lime by dry weight and 0, 5 and 10 % of gypsum (calcium sulphate) were added to a bentonite. Then uncured and cured as compacted samples of mixtures were tested one dimensionall...
Conference Paper
With the increase of soil erosion and encountering with soils with weak bearing capacity in civil engineering projects, soil stabilization become of the uppermost significance. One of the soil stabilization methods is application of a combination of chemical additives like Lime and pozzolanic substances. Alumino-scilicate pozzolans adjacent to hydr...
Article
Full-text available
This paper discusses the influence of adding various amounts of cement to and changing the water content of clayey soil and their effects on controlling the settlement of a superstructure with various improvement area ratios (IARs). As a first step, the physical and mechanical properties of clayey soil from Bandar Imam Port, Iran, with 4, 6, 8 and...
Article
The use of cement as an additive to natural soil has been practiced for a long time in engineering projects. Chemical bonds generated as the result of cement hydration and pozzolanic reactions have been responsible for the increase in strength of cemented soils. The purpose of this research is to evaluate the effect of cement on residual strength o...
Article
Where difficult foundation soils are encountered in civil engineering projects, deep soil mixing method is a choice as a solution to deal with the problem. In this soil improvement method, cement or lime in slurry form (wet method) or in dry powder (dry method) is mixed with the in situ soil. To the knowledge of the authors no comparison between ce...
Article
Full-text available
Geotechnical properties of clay–cement mixtures were examined. Index properties together with compressibility characteristics of laboratory treated clay–cement mixtures in terms of the compression index and pre-consolidation pressure were evaluated. In addition strength characteristics in terms of unconfined compression of different mixtures obtain...
Article
Collection, maintenance and optimized distribution of water is one of the most important and costly projects of water industry in Iran. The selection of the optimized choice among various methods of the construction of the dam body is economical and reduces the construction costs considerably. In recent decades, by the advancement of road construct...
Article
Full-text available
Geotechnical properties of clay–cement mixtures were examined. Index properties together with compressibility characteristics of laboratory treated clay–cement mixtures in terms of the compression index and pre-consolidation pressure were evaluated. In addition strength characteristics in terms of unconfined compression of different mixtures obtain...
Article
Full-text available
In contrast to the clean sands the behavior of sands with fines have complexities that has made it difficult for researchers to reach a general framework for their evaluation and this problem exist today for researchers. In this research work the effect of increasing clay content and also of the gradation of sand on the behavior and shear strength...
Article
The shear strength of soils is due to resistance against movement of soil grains at their contact area which is caused by interlocking and existing bonds between the grains chemical bond is one kind of bonds existed between soil grains that is due to the existance of calcium carbonate and it is called cementation and it could be important factor in...
Article
Traffic jams in big cities have made necessary the need for use of underground metro trains more than ever. However, movement of trains with appropriate speed in between stations produces vibrations that may sometimes be disturbing for people living in the region. Actual measurement of vibrations in Tehran metro is used to predict numerically the v...
Article
In this study, first the integrity of the plastic concrete cutoff wall in Karkheh dam is sought by reviewing constructional controls and observations. Then, the performance of the wall before the extension is modeled using SEEP 3-D computer code and calibrated using actual seepage measurements. The future performance of the wall when reservoir reac...
Article
This study presents the results of laboratory direct shear tests on two natural over consolidated clay samples and compacted laboratory over consolidated samples of different mixtures of bentonite sand. The intact shear strength of over consolidated soils can be obtained from τoc = τNC (OCR)1-m. In that the intact shear strength of over consolidate...
Article
The use of underground structures such as tunnel for subways, highways, material storage, and sewage and water transport is increasing in developed countries. The safety of these facilities during operation in areas with seismic activities such as in Japan, Taiwan and Turkey in recent earthquakes has been questioned. Dynamic effects on these struct...
Article
The main purpose of this research is to evaluate the effect of sand on strength of compacted samples of bentonite sand mixtures. Samples of bentonite with 10,30,50,70, and 80 percent by weight of sand at standard proctor optimum water content were compacted and tested to measure confined and unconfined strength. Unconfined strength of mixtures incr...
Article
The meaning and laboratory measurement of swelling pressure are examined by swelling and swelling pressure tests on undisturbed specimens of Taylor shale from San Antonio, Texas. Swelling pressure response of a shale element is defined in terms of a void ratio against swelling pressure relationship, rather than a single value of swelling pressure,...

Network

Cited By

Projects

Projects (7)
Project
Modification of a triaxial soil test apparatus based on the open loop controlling system