Khalid Farooq

An attempt has been made to correlate relative density and relative compaction based on laboratory and field test data. In this investigation, 185 sandy soil samples were tested in the laboratory. The experimental investigations include classification tests, maximum and minimum density tests, and standard and modified Proctor and in-situ density tests. The values of the dry unit weight of these samples obtained by performing different tests fall between 14.7 kN/m3 and 20.8 kN/m3. Based on these results, linear and multivariate regression analyses were carried out to (a) relate relative compaction and relative density, (b) relate maximum (emax) and minimum void ratios (emin), and (c) express emax and emin in terms of median grain size (D50) and uniformity coefficient (Cu). Experimental and predicted values varied ± 5%, with a 95% confidence interval for the relation between relative compaction and relative density, and for other relations the variation was ± 10%. The proposed equatio...

Predicting the susceptibility of rockfall mountain hazards for block-in-matrix soils is challenging for critical steep cuts. This research illustrates a hydrogeotechnical approach for the prediction of rockfall triggering by performing laboratory tests on low-cohesive-matrix soil collected from steep slopes with 85° to 88° angles at the Tatta Pani site, Karakorum Highway (KKH), and then real-scale moisture-induced rockfall was conducted on site for the validation of laboratory data. Laboratory data of forty quick direct shear tests on samples collected from the field depicted a 3-fold drop in peak shear stress (PS) at the soil–soil interface and a 9.3-fold drop at the soil–rock interface by varying the moisture content from 1% (taken as dry phase) to a critical laboratory moisture content (MC)LC of 21% (taken as wet phase). Similarly, a drop in the elastic modulus (ES) was observed to be 5.7-fold at the soil–soil interface and 10-fold at the soil–rock interface for a variation of mo...

The study aims to evaluate the change in the behavior of sub-base materials being used in road pavements through blending fines of different types in different amounts. Fines are added in aggregate samples as part of gradations proposed by the American Association for State and Highway Transportation Official (AASHTO). Composite samples conforming to AASHTO gradations B and C were prepared by mixing coarse aggregates in varying proportions, ranging from 0 to 15%. Laboratory tests—including aggregate quality tests (abrasion test, flakiness index and elongation Index), physical tests (particle size analysis and specific gravity), and strength test (modified Proctor, California bearing ratio, and permeability test)—were performed on the control as well as the modified samples. It was observed that the material with 0% fines yielded the highest CBR values (greater than 98%) and coefficient of permeability of 4.4 × 10−4 cm/s. However, with the increasing of the fines up to 15%, a substan...

Raising of the Mangla Dam in Pakistan submerged about 15,780 acres of land, resulting in the relocation of 8020 inhabitants to a newly developed town named New City. The new site, consisting of 1300 acres, is in the sub-tropical zone and comprises badland topography. The parent soils (Siwalik clay) pose infrastructure serviceability issues, causing immense loss to property. The study aims to improve the properties of Siwalik clay (base soil) using industrial wastes like marble and glass powders (5 to 20%) and polypropylene fibers (0.25 to 1.25%) as modifiers. Laboratory tests including grain size distribution, Atterberg limits, standard Proctor compaction, unconfined compression, indirect tensile strength, swell potential, and California bearing ratio were conducted on the control and modified clay samples. The results showed that unconfined compressive strength (UCS) and swelling strains (SS) were increased by 43% and 8% at 1.57 kPa pressure with 15% replacement of marble powder. H...

In this research, an effort has been made to develop a correlation between standard and modified proctor compaction test parameters, i.e., maximum dry unit weight (dmax) and optimum moisture content (OMC) of sandy soils. Standard and modified proctor along with classification tests were carried out on hundred and twenty sandy soil samples with different grain size distributions. Based on the test results, the soil samples were classified into various groups of medium to fine sand with nonplastic fines up to 45%. Regression analyses were performed on the experimental data and correlations were proposed to express modified Proctor parameters (dmod and OMCmod) in term of standard Proctor test parameters (dstd and OMCstd). The validation of the proposed predictive correlations was done by using test results of another set of sandy soil samples not used in the development of the correlations. The results of the analyses showed that variation between experimental and predicted values o...

The amount of fines in sand greatly influence the permeability of sandy soils. Thus, this research was conducted to study the effect of plastic and non-plastic fines on the permeability of three types of sands (Lawrencepur sand, Chenab sand and Ravi sand). For this purpose, plastic and non-plastic fines were collected from different location of Lahore. Samples were prepared by mixing plastic and non-plastic fines into each type of sand separately, in amounts ranging from 0% to 50% with increments of five percent. Overall 63 samples were prepared. Sieve analysis and hydrometric analysis were performed to obtain particle size distribution for each sample. Atterberg’s limits were also determined and each sample was classified according to the Unified Soil Classification System (USCS). Compaction tests were performed on all samples as per the procedure in a standard Proctor test. The test samples were compacted in permeability molds with optimum moisture contents to obtain the density, ...

This research is an effort to correlate the index properties of granular soils with the California Bearing Ratio (CBR) and the compaction characteristics. Soil classification, modified proctor and CBR tests conforming to the relevant ASTM methods were performed on natural as well as composite sand samples. The laboratory test results indicated that samples used in this research lie in SW, SP and SP-SM categories based on Unified Soil Classification System and in groups A-1-b and A-3 based on the AASHTO classification system. Multiple linear regression analysis was performed on experimental data and correlations were developed to predict the CBR, maximum dry density (MDD) and optimum moisture content (OMC) in terms of the index properties of the samples. Among the various parameters, the coefficient of uniformity (Cu), the grain size corresponding to 30% passing (D30) and the mean grain size (D50) were found to be the most effective predictors. The proposed prediction models were dul...

The estimation of axial load carrying capacity of bored piles is a complicated problem because it depends upon number of factors which may include boring method, concrete quality, concreting method, experience of the staff and the ground conditions. Validation of pile design through testing of piles either test piles or working piles is considered an essential part of deep foundation design. This is recognized as being the most reliable means of dealing with the uncertainties that may rise during design and construction phase of pile foundations. In this paper, different theoretical methods have been used for the evaluation of pile capacities and then their comparison with the pile load test evaluations have been made for the project of Rathoa Haryam Bridge being constructed in Mirpur Azad Jammu & Kashmir at Mangla reservoir. The subsoil at the bridge site consists mostly of lean clay with ground water table at a shallowest depth of 0.3 m below NSL during the period of field investi...

Expansive soils occur at some places of Pakistan. This paper describes the problems related to expansive soils discovered at Gomal University, Dera Ismail Khan and Shah Abdul Latif University, Khairpur. On the basis of field and laboratory tests for these two sites, certain corrective measures both for the design and construction of foundations/floors have been suggested.

Knowing the engineering properties of geomaterials is imperative to make the right decision while designing and executing any geotechnical project. For the economical and safe geotechnical design, quick characterization of the compressibility properties of the cohesive soil is often desirable; these properties are indeed tedious to determine through actual tests. Therefore, correlating the consolidation parameters of the soils with its index properties has a great significance in the geotechnical engineering field. Several attempts have been made in the past to develop correlations between the consolidation parameters and index properties of the cohesive soils, within certain limitations. However, there is still a need to develop such correlations based on the extensive database, composing of unified plasticity range of soils, i.e., low to high plasticity. In the current study, 148 undisturbed soil specimens were obtained from different areas of Pakistan. Out of which 120 samples we...

Civil engineering infrastructure like roads, bridges, railway tracks, and building structures constructed on fat clay becomes suspicious due to adverse change in the behavior of such soil on interaction with water. To solve such problems especially in underdeveloped countries, application of industrial waste like glass is associated with technical, financial, and environmental benefits. Emphasis of current study is to determine the consequences of powdered glass (GC) on mechanical behavior of fat clay. A fat clayey sample was collected from location of Nandipur, and glass was taken from local glass market in powdered form. Samples were remolded at optimum moisture content and maximum dry unit weight by mixing GC up to 14%. Soil classification tests, modified compaction tests, unconfined compression tests, one-dimensional consolidation tests, California bearing ratio (CBR) tests, and scanning electron microscope were performed. With increasing GC, the consistency limits, compression characteristics, swell characteristics, and optimum moisture content decreased while maximum dry unit weight, yield stress, CBR, and unconfined compression strength increased. Influence of GC is also observed on microstructure of treated clay. After 12% GC, aforementioned geotechnical characteristics behave inversely for selected clay. The optimum GC-value for the tested clay is about 12%, however, this value may vary from clay to clay.

Improvement in engineering properties of expansive soils by mixing ground granulated blast furnace slag (GGBFS) is the main focus of this research. For this purpose two expansive soil samples were collected from DG Khan and Sialkot areas (Pakistan). Classification tests revealed that DG Khan sample belonged to fat clay (CH) while Sialkot soil was lean clay (CL) as classified by Unified Soil Classification System. GGBFS has been added in varying proportions between 0 and 55% in these soil samples to study its role in stabilizing these expansive soils. Based on the laboratory test performed on composite soil samples, it was observed that maximum dry unit weight increased up to 10 % by adding 50% GGBFS in both samples. California bearing ratio (CBR) value showed an increase from 3.2 % to 11.5% for DG Khan soil while CBR values varied from 2.4% to 10.7% for Sialkot soil by mixing 50% GGBFS. Addition of 30 % GGBFS to DG Khan soil reduced swell potential from 8 % to 2 % while in Sialkot soil, 20 % addition of GGBFS reduced swell potential from 5 % to 2 %. Unconfined compressive strength of remoulded sample cured for 28 days increased by about 35% with the addition of 30%GGBFS. The results indicated that mixing of GGBFS in the expansive soil samples have a marked increase in their engineering properties. Also, it is an affective and environmental friendly means to dispose waste of steel industry.

This study is an attempt to evaluate relative density and friction angle of sands on the basis of SPT-N values. In order to develop the relationships among relative density (Dr), friction angle (ϕ) and SPT-N value, field and laboratory test results from sixty boreholes executed in sandy deposit were used. The field tests include the SPTs conducted in the boreholes and the determination of in-situ density at various depths in the boreholes using the pitcher sampler whereas the laboratory tests include routine classification, direct shear box, maximum and minimum density and specific gravity tests. The SPT-N values were observed to vary between 4 and 100 and the in-situ bulk density of undisturbed samples as recovered through pitcher sampler are in the range of 13.24 ~ 18.44 kN/m3. The soil samples are classified as poorly graded sand (SP), poorly graded sand with silt (SP-SM) and silty sand (SM) on the basis of Unified Soil Classification System. The values of minimum dry unit weight fall in the range of 12.22~14.95 kN/m3 and maximum dry unit weight varies in the range of 14.64~19.17 kN/m3 as obtained through vibratory table. Based on the test results, correlation analysis was performed to identify the parameters that affect relative density. The parameters include SPT-N value corrected for field procedures (N60), relative density (Dr), void ratio range (emax–emin), effective overburden stresses (σv’) and in-situ dry density (γdf). Based on the results of correlation analyses, it was observed that SPT-N values alone cannot be related to Dr. Therefore, multiple regression analysis was carried out using Statistical Package for the Social Sciences (SPSS) software and relation between relative density, corrected SPT-N value and effective overburden stress is being proposed. The variation between experimental and predicted values falls within ± 10% at 95% confidence interval. Validation of the proposed correlation was also performed by using an independent data set which indicated that the prediction by using the proposed correlation also falls within ± 10%. Further, comparison of the proposed correlation with other similar relationships already available in the literature was also performed. In addition to the above, correlation between ϕ and SPT-N60 has also been proposed. It has been observed that the experimental and predicted values of friction angle fall within ± 10% with 95% confidence interval. The proposed correlations may be very useful in the field of geotechnical engineering during feasibility/preliminary design stage for rapid estimation of relative density or friction angle based on the field SPT-N60 values.

On August 10, 2010 a series of landslides of more than 90,000 m3 occurred along the Muree-Kohala road in the northern area of Pakistan. A study was undertaken to evaluate the likely impacts of percent saturation and bulk density on mobilized shear strength along the basal rupture surface of the landslide. A series of unconfined compression test and unconsolidated undrained triaxial tests were performed on remolded samples of different densities with varied percentages of saturation. The results of these tests suggest that soil cohesion and friction decreases with increasing saturation. The tests also showed that the shear strength parameters tend to increase with increasing dry density; however, all the samples exhibited a noticeable loss of shear strength with increasing degree of saturation, independent of soil density.Limit equilibrium slope stability analyses were performed along the most probable failure planes, based on shear strength parameters corresponding to degrees of saturation, which varied between 30% to about 100%. This resulted in drop of factor of safety from FS = 1.64 down to 0.51 as the degree of saturation approaches unity.These results suggest that the causative factor in triggering the landslide along Murree-Kohala was the partial saturation of the zone that developed the basal rupture plane. As rain infiltrated the slope, the bulk unit weight of the soil increased, while the shear strength along the developing plane of rupture decreased sufficiently to concentrate shear strain when the material became more than 60% saturation (FS < 1.0).

ABSTRACT In this paper, different models are developed to estimate the compaction parameters of sandy soil using artificial neural network (ANN), least square support vector machine (LS-SVM), and multivariate adaptive regression splines (MARS). The experimental database of Mujtaba et al. (2013) is used for the analysis. The above techniques have been used to improve the regression results. The model equations are established and compared with the regression equation. The MARS model results found to be more accurate and it improved the coefficient of determination to more acceptable levels of 0·88 and 0·81 for the prediction of compaction parameters maximum dry density (γdmax) and optimum moisture content (ωopt), respectively. The results showed that variation between experimental and predicted values of γdmax is within ±4% and that of the ωopt is within ±13% at 95% confidence level. Sensitivity analysis is carried out to evaluate the parameters affecting the output.

In order to understand the mechanism and conditions leading to failure of sandy slopes due to the infiltration of rainwater, constant shear stress drained triaxial tests were conducted on three sets of soil samples-normal sand, gravelly sand and silty sand-taken from natural ...

Rainfall-induced slope failures often occur within a short period of time during or immediately after heavy rainfall. To analyze the mechanism and conditions leading to such failures, constant shear stress drained triaxial tests, which mimic the field stress path, were ...