Determining the mechanical characteristics of soils from static-penetration data

Conclusion 1. For clayey soils, it is possible to confirm, using the curves in Fig. 2, the interlinking of the resultant data from the results of penetration and laboratory determinations of the compression modulus and the undrained-shear strength.2. For sandy soils, it is possible to determine with reliability the angle from Fig. 3 for different penetration depths and different values of q.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 1, pp. 28–30, January–February, 1978.     

Evaluation of the mechanical characteristics of soils from static-penetration data

Conclusions 1. The specific resistance of soil not only beneath the cone of the penetrometer but also against the friction couple should be used to define the prediction of the strength and deformation characteristics of silty-clayey soils more precisely from static-penetration data, and the type of clayey soils should also be considered for the strength characteristics.2. For penetrometers equipped with radiation-logging apparatus, it is possible to evaluate mechanical characteristics of soils under field conditions, using the soil's density in addition to the penetration parameters q and f.3. In developing regional statistical relationships, it should be remembered that the extent to which q and f influence . c, and E is determined largely by what types of soil the statistical sample represents and in what range the physical indicators of its conditions vary.4. To define the recommendations of Construction Rule and Regulation 1.02.07-87 more precisely, it is expedient to use resultant correlation relationships (6)–(8) to evaluate , c, and E from static-penetration data for the genetic groups of quartenary deposits investigated.Translated from Osnovaniya, Fundamenty i Mekhanika Grungov, No. 4, pp. 21–24, July–August, 1990.     

Influence of sample preparation and mode of testing on the shear strength characteristics of laterite soils from Southwestern Nigeria

The Shear Strengths of four laterite soils from Southwestern Nigeria are investigated through:

1. consolidated undrained triaxial compression tests with pore water measurements on Standard Proctor compacted soils and
2. direct shear tests on remoulded soils.

The Shear Strength parameter obtained in both cases are high with those of the first method being generally higher than those of the second method. However, in view of the relative ease of execution, the second method is preferred especially with regards to local/minor and farm constructions.     

Use of static-penetration data to evaluate deformation properties of disperse soils

Equations are presented for estimation of the deformation modulus of disperse (sandy, sandy-loam, and clayey) soils based on data derived from static penetration. The equations are compiled on the basis of multiyear concurrent determinations of the deformation modulus by plates, and the resistance of the soil to the penetration of a type-II standard probe. It is the first time that static relationships have been derived for Jurassic clays, and also sandy loams of various origin.Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 1, pp. 12–16, January–February, 2005.     

Design values of strength characteristics of frozen saline soils

Based on a large number of personal tests and analysis of results of investigations of other authors, the writers comment upon the design values recommended in the SNiP 2.02.04-88 Norms for the strength characteristics of frozen saline soils.NIIOSP Institute. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 2, pp. 27–29, March–April, 1993     

Effect of grain size on the strength characteristics of cement-stabilized lateritic soils

Lateritic soils are readily available all over Nigeria and as such have attracterd several research studies in recent times, the obvious aim being its utilization in the construction industry. This paper gives an account of the work done to further classify the usefulness and limitations of lateritic soils.Cement was used as the stabilizer and the lateritic soils used were obtained from the Ifewara deposits located about 10 km along Ife-Ifewara Road. A sieve analysis of the sample was made. Five different grain size ranges, from coarse to fine, were extracted from the samples. Cubes were moulded by mixing each grain size range with cement in five different proportions, the optimum water/cement ratio of each mix proportion being determined beforehand. The compressive strengths of the cubes were determined after 7, 21, and 28 days of curing in water, respectively. It was established that the higher the laterite/cement ratio, the lesser the compressive strength, and that the finer the grain size range, the higher the compressive strength. Finally, it was observed that cubes made using laterite/cement mix proportions 1:1 and 3:1 kept gaining strength with age while the others were losing strength.     

Use of pore pressure to determine strength characteristics of thawing soils

A procedure for determination of strength characteristics of thawing soils subject to shear under laboratory conditions is proposed on the basis of results of investigations. __________ Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 4, pp. 16–19, July–August, 2007.     

Procedure for monitoring the bearing capacity of cast-in-place piles from results of their dynamic testing

Data derived from investigations of the development of a dynamic method of monitoring the bearing capacity of cast-in-place piles are presented. It is demonstrated that according to results of dynamic tests of cast-in-place piles based on refusal, it is possible to determine the resistance of the soils beneath their lower ends and lateral surfaces. Suggestions are given for consideration of the viscous resistance of bed soils during the installation of cast-in-place piles. __________ Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 1, pp. 16–20, January–February, 2007.     

Evaluation of shear strength of clayey soils by using their liquidity index

 It is well known that overconsolidated clays have higher shear strength than unconsolidated clays. The liquidity index makes possible an evaluation of the consolidation degree of clays. However, there is no empirical information about this relation. In this study, clayey soil samples have been collected from various locations and tested. The tests include the determination of liquidity index and shear strength. Obtained parameters were correlated and regression equations were established among liquidity index and undrained shear strength, presenting high coefficients of correlation (R=–0.93). So, an equation [c_u=e^{(0.026–1.21 IL)}] that makes possible a rough evaluation of the shear strength of clayey soils by using their liquidity index value is an improvement. Received: 10 December 1999 · Accepted: 4 April 2000     

等幅干湿循环对成都膨胀土强度的影响

以成都某工程现场膨胀土样为研究对象,对不同干湿循环次数的膨胀土试样开展直剪试验,结果表明,在相同循环幅度和初始含水率下,随着干湿循环次数的增加,试样的抗剪强度不断减小,最终趋于一个稳定值。     

冰雪融水水源水质特征及可处理性评价

对主要来源于高山冰雪融水的水库水源水质特征进行了调查评价,同时对其可处理性进行了研究。试验结果表明,原水中有机物以亲水性有机物为主,三卤甲烷生成势含量较高,高温期原水具有明显的土霉味特征,2-甲基异莰醇为其主要来源;对该原水的可处理性评价结果表明,混凝剂的种类对原水的絮凝效果影响较大,可根据原水的水质特征进行混凝剂的筛选与设计,以强化水中亲水性有机物的去除;低温低浊条件下的模拟试验结果表明,将絮凝反应时间延长至30min后,能形成粒径较大的絮体,有利于改善沉淀效果。     

On the inconsistency of results of standard methods of determining physical characteristics of soils

Causes of ambiguity in determinations of the moisture content of soils, particle density, and bound water are discussed. Measures are proposed for error reduction, and concepts of geotechnical moisture content and soil-particle density are introduced.     

对某商品混凝土搅拌站强度检测结果异常值的分析

对异常值的深入分析，常常能发现一些很重要的线索，可找出试验上重大误差发生的原因、次数、误差范围等线素。因此我们必须慎重地对待检测中出现的异常值。本文从一起混凝土强度检测的异常值中发现是由检测中的差错引起的，同时发现此差错是检测中的普遍现象，望大家对此引起重视。     

Residual shear strength of soils

Conclusion The relations between the residual shear strength of soils and their index properties have been proved. Best correlation appeared to be between the residual shear strength and the index of plasticity. However, the correlation is not enough to enable the simple index tests to be substituted for the complex residual shear tests.