Akbar Cheshomi

• Associate Prof. of Engineering Geology
• University of Tehran

Indentation test results and well-logging data are indirect methods of estimating Young’s modulus (E) and uniaxial compressive strength (UCS). The current study compared the results of indirect methods for a well in an oil field in southern Iran. The indentation tests were conducted by an indenter with a diameter of 260 mn on over 500 drill cutting...

The mechanical characteristics of rocks stand as pivotal parameters across multiple engineering domains, including petroleum, mining, civil, and environmental engineering. Among these attributes, the phenomenon of crack propagation holds paramount importance. This intricate process encompasses the initiation point, trajectory of extension, and morp...

Determination of the strength parameters of intact rock samples is an important requirement in rock engineering. On the other hand, proposing a simple method as an index to estimating the strength parameters is one of the tasks of engineering geology. The conventional triaxial test (CTT) is one approach used to determine shear strength parameters (...

Due to heterogenous nature of bimsoils (complex mixture of rock blocks within a soil matrix), studying their behavior through conducting in situ and laboratory tests is really difficult. By developing methods for shear parameters estimation of bimsoils, engineers will be able to have insight about these parameters values without conducting expensiv...

The pressuremeter test (PMT) and plate load test (PLT) are principal in-situ experiments for measuring soil stiffness and deformation parameters. Although the PLT can be costly and complicated at great depths the PMT can be easily done in a borehole. Empirical equations linking the parameters from these tests can be useful for cross-checking the pa...

Adhesion between metal surfaces and soil can have significant effects on soil-tool interaction. The cone pull-out test (CPT) and piston pull-out test (PPT) for adhesion assessment were used in this study on smectite, illite and kaolinite clays at different water contents. In the CPT, the tangential adhesion stress (TAS) and cone adhesion (CA) were...

Seymareh Dam on Seymareh River is one of the highest concrete dams in Iran. The dam reservoir lies on Quaternary deposits, Gachsaran and Asmari formations. About 60 springs were identified downstream of the dam before impounding the reservoir. The springs increased up to more than 200 in number following impounding the reservoir up to elevation (El...

Unconfined compressive strength (\(S_{u}\)) is one of the soil engineering parameters used in geotechnical designs. Due to the temperature changes caused by some human activities, it is important to study the changes in \(S_{u}\) at different temperatures. On the other hand, due to the differences in the mineralogical composition of clay soils, it...

Fracture toughness is the key to analysis of failure progress, which can be defined under different stress conditions as fracture toughness modes. The mode I fracture toughness (KIC) of rock is an important parameter in petroleum and reservoir engineering; however, preparation of standard samples for determination of this parameter is costly and ti...

Today, the assessment of erosion and sediment yield of catchments is among the fundamental issues in water resources management and environmental problems in developing countries. In this regard, empirical methods have received much more interest than other methods due to the lack of reliable hydrometric and partially precise data, especially for l...

Approximately 49% of oil reserves and 55% of natural gas reserves of the world are lied in carbonate reservoirs. These amounts for Iran are 85% and 90% respectively. Also, because of the number of carbonate formations making up the Iranian stratigraphy in several sedimentary flanks, it is important to assess engineering features of these rocks and...

Mechanical properties of rocks are very important parameters within petroleum engineering, mining engineering, and civil and environmental engineering designs. One of them is how a crack propagates in a rock. This includes the starting point, the trajectory of propagation, and the total morphology of cracks in rocks. There are several distinct meth...

Unconfined compressive strength ( S u ) is one of the soil engineering parameters used in geotechnical designs. Due to the temperature changes caused by some human activities, it is important to study the changes in S u at different temperatures. For this purpose, kaolin, illite and montmorillonite clays with a liquid limit (LL) of 47, 80 and 119 r...

The LCPC method is one of the most common abrasion tests used for determining soil and rock abrasivity. LCPC abrasivity coefficient (LAC) and LCPC brittleness coefficient (LBC) are two parameters obtained from this method. The rotation speed (RS) and rotation time (RT) are two factors that affect the results of this experiment. In this paper, the e...

The rolling indentation abrasion test (RIAT) is a recently developed method for measuring rock abrasivity. In this study, RIAT tests were performed on 17 plutonic rock samples and the weight lost by the mini-disc cutter (mg) after testing (RIATa), the mean value of 10 evenly distributed measurements of the cutter penetration depth into the rock in...

Pressuremeter Test (PMT) and shear wave velocity (VS) are two important in-situ tests for determining soil deformation characteristics in different strain levels. The PMT is an expensive and time-consuming test that can measure pressuremeter modulus (EPMT) of soil and rock. The VS is a low-cost test for determining soil deformation through the seis...

The wear of cutting blades during the preparation of building stones is an inevitable issue that occurs due to the contact of the blade with rock components. The present study aims to investigate the feasibility of proposing experimental relations of strength parameters and mineralogical hardness with Cerchar and LCPC tests. For this purpose, 18 sa...

Dry pluviation is a technique applied for preparation of sandy soil samples for physical modeling. In this method, soil particles rainfall in the mold after passing through the mesh with certain opening sizes. In this study, a dry pluviation device was designed and manufactured to examine the effect of shutter properties including the hight of fall...

Combining geological and geotechnical data is quite beneficial for planning and designing urban development projects. Isfahan city is located on Jurassic shale and sandstone and Quaternary deposits. It is important to identify the engineering properties of these rock units and soil layers to distinguish them in construction projects. In this resear...

Abrasivity is one of the most important properties in drilling and tunneling projects. This phenomenon, which increases costs and significantly reduces drilling efficiency, is quantified using various techniques. The Cerchar test (CAI) and the Rolling Indentation Abrasion Test (RIAT) are, respectively, one of the oldest and newest methods in this r...

Investigation of the effect of temperature on soil strength is one of the issues which has been considered by many researchers in recent decades. In this study to investigate the effect of temperature on the undrained shear strength (Cu) of clay soils, a cell with the capability of both changing and keeping fixed the temperature of sample, was desi...

The use of in-situ soil testing has become popular in many geotechnical projects because of its high measurement accuracy and low disturbance of the soil sample during the testing process. Pressuremeter Test (PMT) and standard penetration test (SPT) are two important in-situ tests in geotechnical engineering. The former is an expensive and tim...

A pressuremeter test (PMT) is one of the in situ tests, which is used to evaluate deformation and strength parameters of soils for various projects, including subway projects. The limit pressure (PL) and undrained shear strength (Su) are the key parameters that are obtained directly and indirectly from the pressuremeter testing results. This resear...

Shear strength parameters of soils are essential in civil projects. Two important parameters for these projects are the Ø’ and C’ of saturated soils, which are usually obtained by the triaxial shear test. One TST may take weeks and it costs too much. Also, in a vast project, it is practically unreasonable to carry out a large number of the tests. T...

Description and Understanding the sedimentary environment helps a lot in the initial estimation of the engineering properties of materials and planning of geotechnical studies. Most of the quaternary sediments (coarse and fine grained) of the Isfahan city were deposited by the Zayandehrood river. Understanding the geotechnical characteristics and s...

Investigation of the effect of temperature on soil strength is one of the issues which has been considered by many researchers in recent decades. In this study to investigate the effect of temperature on the undrained shear strength (Cu) of clay soils, a cell with the capability of both changing and keeping fixed the temperature of sample, was desi...

The increasing amount of demolition and construction waste (D&CW) materials has created many problems in large cities. Recycling waste materials helps to protect the environment. D&CW can be used in many projects, especially in road construction, retaining walls, landscaping and pavements. In this research, a project in which, D&CW used as fill mat...

Today, with regard to land shortage and ever-increasing growth of the world’s population, construction on loose soil has been inevitable. Therefore, to deal with this issue, it is necessary to improve project site materials. The conventional soil improvement techniques are limited due to high costs and environment unfriendliness. In this regard, mi...

Land subsidence in Tehran Plain, Iran, for the period of 2003–2017 was measured using an InSAR time series investigation of surface displacements. In the presented study, land subsidence in the southwest of Tehran is characterized using InSAR data and numerical modelling, and the trend is predicted through future years. Over extraction of groundwat...

The lateral extent, depth of densification, and environmental effects of dynamic compaction (DC) were investigated for a very loose to loose silty sand layer with thickness varying from 6 to 12 m in a coastal area in southern Iran. Cone penetration testing (CPT) was done at different distances from the center of the point of impact before and after...

The Chamshir water conveyance tunnel (CWCT) with a length of 7.4 km passes through soft marlstones and mudstones of the Aghajari formation and strong conglomerates and sandstones of the Bakhtiari formation, which are two main widespread formations in the Zagros simply folded zone in southwest Iran. This tunnel with a boring diameter of 5.3 m is exc...

Cone penetration testing (CPTu) and pore pressure measurement have long been used to estimate the undrained shear strength (Su) of clay, although the evaluation of strength from CPTu results in fine-grained soil is mostly empirical. In fact, for various reasons, in-situ methods such as CPTu and laboratory methods may give different results for Su f...

An increase in urban population and the reduced number of suitable lands for construction projects have necessitated the need for ground improvement methods with no environmentally detrimental effects. Microbial-induced calcite precipitation (MICP) is a relatively environmentally friendly method for soil regeneration. In the present paper, X-ray di...

Elastic modulus (E) and uniaxial compressive strength (UCS) are very important engineering parameters that is required for many engineering projects. In some projects such as well drilling for oil production, deep underground tunnels in crushed zone, due to the depth of the well and fractures of rocks, there are some problems for obtained standard...

Different methods have been introduced for estimating the performance of tunneling boring machines (TBMs) for each area; therefore, their use in other projects may lead to errors in different geological conditions. Therefore, it is necessary for each project to use models that have similar geological conditions with the project. In this paper, usin...

Due to the vital role of springs in day to day life of farmers and villagers in the study area, evaluating the impacts of constructing Kerman water conveyance tunnel on springs discharge rate is an essential task. Kerman tunnel with diameter of 3.9 meters is 38 Kilometers long and is constructed in two lots, northern lot (south west of Golzar villa...

Due to the vital role of springs in day to day life of farmers and villagers in the study area, evaluating the impacts of constructing Kerman water conveyance tunnel on springs discharge rate is an essential task. Kerman tunnel with diameter of 3.9 meters is 38 Kilometers long and is constructed in two lots, northern lot (south west of Golzar villa...

In this study, using the collected data from 4 slope failures in one of the central mines of Iran, the shear strength parameters of jointed and crushed rock masses using back analysis method are calculated and its results are compared with the values obtained from the empirical methods. In this regard, firstly, the identification of failures is inv...

Due the rapid development of technology and use of computer programs in geotechnical studies in recent years, the need for developing new programs for overcoming the challenges faced in geotechnical studies is growing. Water inflow into tunnels could result in instabilities in rock mass, causes extra pressure on tunnel lining, and damages the tunne...

The abrasive properties of stone that wear away and destroy the cutting blades and drill heads of boring machines increase the cost of construction and mining projects. This study investigated the effects of petrographic characteristics on the abrasiveness of granitic building stone. The composition and abundance of minerals forming each sample wer...

The second lot of Tehran-Shomal freeway with approximately length of 22 km is on the development phase to select the suitable rout in central part of Alborz Mountain, northern Iran. There are three main proposed routs for construction of this freeway. According to the geological condition of the area, landslide hazard assessment is one of the main...

Mechanized tunneling through clayey formations is threatened by encountering the clogging problem. Adhesion stress, as the tendency between clay and a metal surface, leads to clogging between TBM and excavated materials. Some empirical clogging classification charts were prepared based on the experienced clogging problems. Moreover, experimental at...

Because of providing drinking water of two cities by Sarab-Garm spring, it’s important to carry out studies to determine the effect of tunnel boring activities on discharge rate of Sarab-Garm spring. In this study by means of probabilistic assessment of tunnel inflow, Dematteis method and numerical modelling the effect of tunnel boring activities o...

A number of methods have been proposed to indirectly assess the uniaxial compressive strength (UCS) of intact rock in the drilling of oil wells and underground drilling. Indentation testing is a method in which an indentor ‎of a specific diameter penetrates a particle of rock and the force-displacement curve is plotted to determine the critical tra...

Lime and fly ash are admixtures used to reduce the swelling of clay. The current study added 3%, 5%, and 7% (wt) of lime to sulfate-bearing clay and found that chemical reactions between the lime and sulfate-bearing clay led to ettringite formation as the lime content increased. This mineral shows good potential for water absorption, which increase...

The tendency of clay particles to stick other surfaces means it is adhesive and can cause clogging of tunnel boring machines. Clogging arising from adhesion hinders or halts tunneling operations. The nature of adhesion in the interaction of soil and metal surfaces must be clarified in order to control its occurrence. This paper investigates the adh...

Zagros water conveyance tunnel (ZWCT) is a 49km tunnel designed for conveying 70m3/s water from Sirvan River southward to Dashte Zahab plain in western Iran. This long tunnel has been divided in 3 Lots namely 1A, 1B, 2. By November 2014, about 22km of the Lot 2 (with a total length of 26km) has been excavated by two double shield TBMs from two sout...

Construction of the second lot of Tehran-Shomal freeway is facing the big challenges because of locating in the mountainous terrain with complex geological condition. Many technical studies show that there are two main variant for this project including the long tunnels construction or construction of freeway on the ground with big trenches. In thi...

LONG ABSTRACT Clogging and blockage of cutter head and disc cutters is one of the major problems during tunnel excavation in clay bearing soils and rocks that can lead to delays in construction time and to conflicts regarding additional costs and cause reduction in performance of excavation process. This phenomenon affects all types of closed-face...

Researchers have introduced a variety of innovative methods for indirect determination of uniaxial compressive strength (UCS) for use when preparation of standard cores is impossible or uneconomical, such as for oil wells or underground drilling. One indirect method is the single-particle strength test. The present study evaluated the use of this m...

In restricted sampling conditions such as oil well drilling, appropriate rock samples do not exist for measuring unconfined compressive strength (UCS) using conventional standard methods during the excavation. Loading on small rock samples is one of the new feasible methods for assessment of UCS in restricted sampling conditions. In this paper 510...

The adhesion of clay minerals to metal surfaces leads to clogging of equipment during mechanized tunneling through clay-bearing formations. Among proposed methods to measure adhesion and evaluate clogging potential, Piston Separation Device is found practical and capable to develop. The Device was redesigned based on literature and built in this st...

Predicting TBM performance and cutter consumption in tunneling projects plays an important role in project schedule and cost. To predict these parameters, it is necessary to have reliable input parameters and suitable predictive models. In this study, a new empirical models (Hassanpour et al. 2011, 2014) used to anticipate TBMs performance paramete...

Clogging occurs during mechanical tunneling with a Tunnel Boring Machine (TBM) because of adhesion of clayey soils to the cutter head and conveyor system. The present study examined the effects of water and sand contents on clogging in Montmorillonite clayey soil. Testing was carried out using an adhesion test device on 28 samples with different wa...

The Menard pressuremeter test is a relatively expensive in situ test, which generates useful information about the strength and deformation properties of any soil and weak rock, which is carried out in some projects. On the other hand, the SPT test is a rather inexpensive, simple and typical in situ test used to determine the engineering properties...

The uniaxial compressive strength (UCS) of intact rock is an important mechanical parameter which is required for many engineering projects. In some engineering projects such as well drilling for petroleum production, due to the depth of the well, there are some limitations for obtaining rock core samples and determining the UCS. Nevertheless acqui...

It is often difficult to directly obtain specific design parameters of interest. In these situations, estimation based on empirical correlations is an alternative. The deformation modulus of a rock mass, which is important to know for engineering projects, is measured by in situ tests, such as plate bearing, flat jack, pressure chamber, borehole ja...

Abstract: The standard penetration test (SPT) is the in situ test most commonly used to investigate the properties of silt, clay, sand and fine gravel. The Menard pressuremeter test (PMT) can be utilized to obtain the strength and deformation properties of any soil or weak rock. Pressuremeter test results is more reliable than standard penetration t...

J. H. Atkinson has raised a number of relevant questions but it is important to note that the main message of our paper was to include specific geology to simplify the characterization of a soil, and the studied soil is a cohesive coarse and non-textbook material so its characterization is difficult because of difficulties in sampling and field tes...

Shear wave velocity is one of the important factors representing the dynamic characteristics of soil layers. Hence, many researchers have focused their studies on determining shear wave velocity by direct field measurements or expressions developed by other soil parameters. The shear module and damping ratio of the soil layers also play a similar r...

Very coarse-grained alluvia are challenging materials in geotechnical site characterization. The paper presents a method that can be used to find local correlations between the angle of friction and particle shape for very coarse-grained alluvia. The method is based on the results of a number of in situ direct shear tests carried out in horizontal...

The city of Tehran is founded on Quaternary alluvium, which has been geologically classified by Rieben. The city is located at the foot of the Alborz Mountain Range, which is basically composed of Eocene pyroclastic deposits (green tuff) and other volcanic rocks. The geology and the morphology of the Tehran region is similar to that for other citie...

Evaluation of liquefaction potential of soils is one of the important aspects of geotechnical earthquake engineering practice. After the publication of "simplified procedure" in 1971, it has become a widely used method of practice for liquefaction assessments. Several in-situ tests have been used for evaluating resistance of soils to liquefaction....