Hasil untuk "Engineering geology. Rock mechanics. Soil mechanics. Underground construction"

Riwaj Dhakal, Misko Cubrinovski

One-dimensional (1D) dynamic effective stress site response analysis (ESA) is performed for profiles at the port of Wellington, New Zealand (CentrePort), which contains reclamation fills comprised of gravel-sand-silt (G-S-S) mixtures and hydraulic fills. The first phase of the study realistically simulates three recent earthquake case histories while considering modelling uncertainties by using the PM4Sand and the Stress-Density constitutive models. The results illustrate possible mechanisms explaining the severity of liquefaction manifestation and soil ejecta characteristics observed in G-S-S fills through careful engineering interpretation of the response. Challenges for 1D ESA to explain complex manifestation patterns affected by two-dimensional variability in fill composition and response characteristics are illustrated for the hydraulic fills. In the second phase of analyses, ESA-based response measures are proposed to quantify the severity of the liquefaction response for a range of input seismic demands. The response characteristics show very small scatter despite using a range of different input ground motions and two soil constitutive models. Results illustrate the capability of ESA to capture details of the liquefaction response such as the similar threshold seismic intensity for liquefaction triggering of the loosely deposited fills, different maximum response of the sites reflecting the differences in the thicknesses of the fills, and the evolution of the response from triggering to maximum reflecting differences in depositional characteristics.

Baca Michał, Rybak Jarosław

Laterally loaded pile foundations are more commonly employed in geotechnical engineering due to their widespread utilisation in contemporary construction projects, with examples including wind turbines. The most effective method for estimating pile lateral capacity is a static load test conducted in a natural scale. However, there are some challenges associated with field performance tests, which can be avoided by conducting them on model piles in a laboratory scale. This article presents the initial results from a series of lateral static load tests conducted on steel pipe piles in a laboratory scale. Based on the retrieved results, an analysis of the loaddisplacement pile lateral behaviour was performed, and the pile lateral bearing capacities were estimated with approximation methods. In addition, an approximation error analysis was performed.

WANG Chao, ZOU Jinfeng, , SHU Dan, WU Qinhua

In order to investigate the safe construction distance of shield tunnel crossing the pile foundation of the existing bridges, taking the crossing construction at the orthogonal side as an example and considering the influences of the pile shear effects, we use the Pasternak two-parameter foundation model to establish the equilibrium differential equations for the horizontal displacements of the soil in the middle of the pile foundation of the existing bridges and the tunnels under construction, and the analytical solutions for the horizontal displacements of the pile-tunnel intermediate soil are derived. Based on the cusp catastrophe theory, the standard expression for the potential function of the pile-tunnel intermediate soil and the sufficient and necessary conditions for its system to be suddenly destabilized are determined. Accordingly, the method for calculating the critical safe distance of the pile foundation of the existing bridges is established, and its engineering applicability is verified through the numerical simulations and field measurements. The method is used to analyze the main influencing factors for the critical safe distance of the pile foundation of an existing bridge. The results show that the critical safe distance is approximately an exponential function with the diameter ratio of the pile foundation of the bridge, and the two parameters are positively correlated, while it follows a quadratic function of the shield tunnel depth ratio, and first increasing and then decreasing as the depth ratio increases, and reaches the maximum value when the depth ratio of the shield tunnel is 8.1. The theoretical values obtained by the proposed method and the estimated ones by the numerical simulation are well fitted, and the measured results and the relevant specifications also further verify the engineering applicability of this method. The proposed method provides theoretical guidance for the rational development of the design and construction program of similar tunnel crossing projects.

XIE Jun

The large quarry face with a strike length of 3 300 m in Sijiazhuang Mine features high gas reserve, large gas outflow and its upper corner is easy to exceed the limit.This study adopts the gas management technology of extracting the gas from the coal seam by drilling large-diameter downhole holes.We established a numerical model of fluid-solid coupling by considering the superposition effect of drill holes to analyze the evolution of gas pressure, effective extraction radius, and the effect of gas extraction when the diameter of drill holes is 113 mm and 400 mm respectively.The results show that ①after implementing pre-extraction technology in the large diameter drill hole, the effective extraction radius of the drill hole increased by 21.12 %; ②When introducing the coefficient k=pm/pc as a judgment index of the superposition effect, taking the effective extraction radius of a single 113 mm diameter drill hole as a reference, the effective radius of a 113 mm diameter drill hole is improved by 3.7 times compared with that of a single hole when using a common diameter drill hole for multi-hole extraction; ③The concentration of the gas extracted from the drill hole increased by 2 times, and the pure amount of extraction increased by 5 times, which provides technical and theoretical references for the gas management and safe production of the working face of large mining fields.

Xiaokang Li, Xu Li, Jiankun Liu

The soil freezing characteristic curve (SFCC) plays a fundamental role in comprehending thermo-hydraulic behavior and numerical simulation of frozen soil. This study proposes a dynamic model to uniformly express SFCCs amidst varying total water contents throughout the freezing-thawing process. Firstly, a general model is proposed, wherein the unfrozen water content at arbitrary temperature is determined as the lesser of the current total water content and the reference value derived from saturated SFCC. The dynamic performance of this model is verified through test data. Subsequently, in accordance with electric double layer (EDL) theory, the theoretical residual and minimum temperatures in SFCC are calculated to be −14.5 °C to −20 °C for clay particles and −260 °C, respectively. To ensure that the SFCC curve ends at minimum temperature, a correction function is introduced into the general model. Furthermore, a simplified dynamic model is proposed and investigated, necessitating only three parameters inherited from the general model. Additionally, both general and simplified models are evaluated based on a test database and proven to fit the test data exactly across the entire temperature range. Typical recommended parameter values for various types of soils are summarized. Overall, this study provides not only a theoretical basis for most empirical equations but also proposes a new and more general equation to describe the SFCC.

LI Tao , ZHAO Hongyang , WENG Bohang , HUANG Xiaoji , ZHANG Zhongyu

In order to study the influences of different contents and shapes of fine particle on the mechanical properties of calcareous mixed sand, the angular quartz powder and round glass beads are used as the fine particle materials and mixed with the calcareous sand in different proportions, and the strength characteristics and crushing characteristics of the calcareous mixed sand are studied and analyzed through the ring shear tests. The results show that the softening characteristics of the two kinds of mixed sand are obvious in the medium density state. The softening coefficient increases first and then decreases with the increase of the fine content, and reaches the maximum value when the fine content is 10%. The softening coefficient of the samples containing the glass beads is larger when the fine content is the same. The apparent cohesion of the calcareous sand is obvious and decreases with the increase of the fine content, and the decreasing trend of the samples containing the glass beads is obviously larger than that of the samples containing the quartz powder because of their lower embedding and biting capability. The deformation of the pure calcareous sand appears in the form of dilatancy, and with the increase of the content of the fine particle, the shear shrinkage of the mixed sand gradually increases, the peak strength and relative breakage rate gradually decrease, and the change of the mixed sand containing the glass beads is more significant.

Hua Jiang, Jiachen Zhu, Xiaoyan Zhang et al.

Abstract Tool wear is a noteworthy problem in the process of shield tunneling, and the degree of wear varies with stratum. The sand‐pebble strata in Beijing are typically mechanically unstable. However, many subways are buried wholly or partially in sand‐pebble strata. Taking the Beijing New Airport line tunneling project as research background, this study evaluated the wear characteristics of the multiconfiguration rippers of a 9‐m‐diameter spoke‐type shield tunneling machine in a sand‐pebble stratum. The wear values of five ripper teeth and ripper flanks were analyzed based on field‐measured data from the Beijing New Airport line project. As the analytical results show, the wear value generally increases as the installation radius enlarges with the rise of cutting trace length. The wear of the 190‐rippers was divided into five categories: pedestal wear, ripper teeth collapse, uniform wear, ripper teeth falling off and ripper flank wear. Uniform wear of the ripper teeth and ripper flank wear were the two abrasion types of the 190‐rippers. The teeth of the 155‐rippers mostly maintained their cutting capacity under the protection of the 190‐rippers. A wear prediction model of linear fitting field data was developed for a 190‐ripper face to obtain the optimum shield driving distance in the sand‐pebble stratum. The average wear coefficients of the 190‐ripper before and after replacement matched well, being 0.045 and 0.066 mm/km, respectively. The results of this study provide a theoretical reference for tool wear prediction in shield construction under similar geological conditions.

Amir Moradinejad, Seyed Ahmad Hossieni

Introduction Due to river dynamic nature, the morphological characteristics of rivers are always changing and these changes can have negative effects on structures built along rivers, agricultural lands, etc. Rivers have been one of the most important factors in the geomorphological processes of the land and the erosion cycle, and so far, extensive studies have been conducted on the morphological changes of rivers and the factors affecting them. The instability of the river channel and its sediments not only destroys the marginal lands and facilities adjacent to the river bank, but also the sediments caused by erosion in some cases include a significant amount of the total sediments that the river flows.Materials and Methods The morphology of a part of Qarachai river in Markazi province of Khondab city from the top of Shaveh village to the bottom of Farab village, with a length of 12 km has been studied. First, the location of the Qarachai River watershed and the study area have been determined using digital topographic maps and ArcGIS10.2 software. Then satellite images and aerial photographs of the study area, which are the most important tools for studying changes in river paths, have been collected in two time periods. In the following, the aerial photos scanned in Photoshop software are photomosaic and are referenced in ArcGIS10.2 software using fixed points such as villages, bridges, etc., using aerial photographs of the year. 1968 Satellite images of Landsat sensor of 2021 have been digitized in two time periods in ArcGIS10.2 software environment. Results and Discussion Changes in wavelength and valley length in the two time periods studied in the study section of the river show that in the study area, the morphology of the river has not undergone major changes and the curvature of the study area has not changed much. The study of changes in wavelength and valley length and arc length in the two periods studied shows that the average wavelength in 1968 is about 413.25 and in 2021 is about 387.63. The wavelength in 1968was longer than in 2021. The changes compared to the 53-year period are about 6.2% and very small. As the wavelength decreases, the distance between the windings also decreases. The changes in the length of the valley relative to the meanders. The average length of the valley in 1968 is about 224.46 and in 2021 is about 12.21. Changes in the two timelines are about 5.5% and are very small.Conclusion The general pattern of the river from 1968 to 2021 has not changed significantly and is always twisting. The number of windings during 53 years is the same as 23 windings. The fact that the number of meanders is constant indicates that there is no change in the morphological pattern of the river. The results of extraction and statistical comparison of geometric parameters of this part of the river such as wavelength, sine coefficient, width to depth ratio, etc. show that the sine coefficient of the river from 1.5 to 1.3 The wavelength and radius of the tangent circles on the twists and turns have also increased. The average curvature coefficient in the 40s is about 1.11 and in 2021 is about 1.08. According to the division table of rivers, this period studied by Khondab river has a sinusoidal state and has not changed much in two time periods.

WANG Shuo 1, ZENG Chao-feng 1, XUE Xiu-li 1, LI Ming-guang 2, CAI Gang 1

The finite element model is established to investigate the development of deformation of enclosure wall during dewatering in a leaky aquifer by using ABAQUS on the basis of a practical pre-excavation dewatering test. The results show that when there is hydraulic connection between the inside and outside of a foundation pit, under the influences of an aquitard, the difference of pore pressure at both sides of enclosure wall (ΔP) increases first, then decreases, and finally tends to be stable during the pumping. As a result, the deformation of enclosure wall first increases, then decreases and finally becomes stable. However, when there is no hydraulic connection between the inside and outside of the foundation pit, ΔP increases monotonously and tends to be stable soon. The deformation of enclosure wall no longer first increases and then decreases, but increases monotonously.

ZHANG Deng-fei 1, CHEN Cun-li 2, SHU Ying-tao 3, PANG Teng-teng 4

The isotropic compression tests with simultaneous gas permeability measurements are performed for intact loess with various water contents in three regions. The behaviours of compression deformation and change of induced gas permeability of intact loess are analyzed. The correlation between gas permeability and compression deformation is discussed. The formula of compression curve of intact loess is proposed to characterize the compressive deformation under the coupling of moisture and stress, in which the structural parameter defined by gas permeability is included as a known parameter. The results suggest that changes of gas permeability of intact loess are found to have a good correlation with volumetric deformation during isotropic compression tests. The structural potential difference of intact loess caused by the fabric and moisture and its damage induced by the stress can be reflected by the change in gas permeability. The gas permeability ratio corresponding to the yield stress at the ratio of a certain water content to the reference water content is defined as the structureal ratio parameter, and it is introduced into the isotropic stress variable to lead to a normalized compression curve of intact loess with various water contents. Regarding the compression curve at the reference water content as the reference state, a unified and continued description of the compression deformation before and after yielding for unsaturated intact loess is proposed, and the calculated results agree well with the test ones.

Murtala Umar, Khairul Anuar Kassim, Kenny Tiong Ping Chiet

Y. Shokin, Z. Shaimardanov

صفورا ناهیدان, فرشید نوربخش

سابقه و هدف: ارتباط تنگاتنگی بین فعالیت‌های میکروبی و محیط فیزیکی خاک وجود دارد. موقعیت هر آنزیم در خاک، به موقعیت سوبسترا، خصوصیات آنزیمی و یا جانداران تولید‌کننده آن‌ها نسبت داده شده است. توپوگرافی (موقعیت شیب) به عنوان یکی از عوامل مهم خاک‌سازی، نقش بسزایی در تحول، تکامل و تغییرپذیری خاک‌ها ایفا می‌کند. تغییرات مکانی فعالیت آنزیم‌ها در مقیاس زمین‌نما در حقیقت به وسیله فرآیندهای پدولوژیکی و هیدرولوژیکی کنترل می‌شوند. اثر توپوگرافی (موقعیت شیب) بر توزیع اندازه خاکدانه و فعالیت آنزیم‌ها در مطالعات پیشین مورد بررسی قرار گرفته است. موقعیت شیب ممکن است بر الگوی توزیع فسفومونواسترازهای اسیدی و قلیایی در خاکدانه‌ها اثر متفاوتی بگذارد. بنابراین هدف از پژوهش اخیر بررسی الگوی توزیع خاکدانه ای فعالیت فسفاتاز اسیدی و قلیایی در موقعیت‌های مختلف شیب می‌باشد. مواد و روش‌ها: نمونه برداری از سه موقعیت قله شیب، شیب پشتی و انتهای شیب یک اکوسیستم مرتعی انجام گرفت. از عرض هر موقعیت شیب، سه نقطه به عنوان سه تکرار با فاصله 10 متر از یکدیگر در نظر گرفته شد. در هر موقعیت شیب، در یک دایره به شعاع 2 متری، 10 نمونه خاک از عمق 0-10 سانتی‌متری جمع‌آوری و با یکدیگر مخلوط شدند. پس از اندازه گیری ویژگی‌های عمومی خاک‌ها، خاکدانه ها به روش الک تر جدا شده و توزین گردیدند. کربن آلی، فسفر قابل استفاده، فسفاتاز اسیدی و فسفاتاز قلیایی درون شش گروه اندازه خاکدانه (4-2، 2-1، 1-5/0، 5/0-25/0 ، 25/0-05/0 و05/0> میلی متر) اندازه گیری شدند. یافته‌ها: نتایج نشان داد که توزیع اندازه خاکدانه تحت تاثیر موقعیت شیب قرار گرفت. کمترین و بیشترین درصد جرمی ریزخاکدانه‌ها (05/0-25/0 میلی‌متر و کوچکتر از 05/0 میلی متر) به ترتیب در قله شیب و شیب پشتی مشاهده شد. تشکیل خاکدانه‌های درشت با مقدار کربن آلی خاک در طول شیب در ارتباط بود. خاکدانه‌های درشت 4-2 میلی متری در شیب پشتی به میزان 85 درصد نسبت به قله شیب کاهش یافتند. دیگر نتایج پژوهش نشان داد که کربن آلی و فسفر قابل استفاده در درشت خاکدانه‌ها به ترتیب به میزان 38 و12 درصد بیشتر از ریزخاکدانه ها می‌باشند. هر دو آنزیم فسفاتاز اسیدی و قلیایی در درشت خاکدانه ها بیشتر از ریزخاکدانه ها بودند و فعالیتشان با کاهش اندازه خاکدانه به میزان 42 درصد کاهش یافتند. اثر موقعیت شیب بر الگوی توزیع فسفومونواسترازها متفاوت بود. انتهای شیب و شیب پشتی به ترتیب دارای کمترین فعالیت فسفاتاز اسیدی و قلیایی بودند. اگرچه نسبت فعالیت فسفاتاز اسیدی به کربن آلی و فسفر قابل استفاده در تمام خاکدانه‌های موقعیت شیب پشتی دارای بیشترین مقدار بود، الگوی توزیع فعالیت نسبت فسفاتاز قلیایی به کربن آلی و فسفر قابل استفاده در موقعیت های مختلف شیب به اندازه خاکدانه‌ها بستگی داشت. تنها فسفاتاز قلیایی با فسفر قابل استفاده در طول شیب تپه مورد مطالعه همبستگی معنی داری (001/0 P = 72/0=r) نشان داد. نتیجه گیری: به طور کلی نتایج حاکی از آن است که هر دو آنزیم فسفاتاز اسیدی و قلیایی الگوی توزیع مشابهی را در خاکدانه‌ها داشتند ولی تحت تاثیر موقعیت شیب دارای الگوی توزیع متفاوتی بودند که ممکن است ناشی از منشا متفاوت آن ها باشد. همچنین از آن جایی که درشت خاکدانه ها دارای فعالیت آنزیمی، کربن آلی و فسفر بیشتری بودند، حفاظت از ساختمان خاک و درشت خاکدانه به ویژه در موقعیت های شیب حساس به فرسایش می تواند با حفظ ذخایر فسفومونواسترازی بر چرخه بیوشیمیایی فسفر تاثیر بگذارد.

Truty Andrzej

Nonlinear soil–linear structure computational strategy is commonly accepted in the community of geotechnical engineers using advanced finite element software for solving complex soil–structure interaction problems. However, further design procedure of the structural elements is carried out using increased values of the computed elastic stress resultants. It is absolutely not clear whether this method is conservative and, therefore, whether safe or not. To tackle this problem, a fully consistent nonlinear analysis of a deep excavation protected by the diaphragm wall is analysed here. The subsoil is modelled using the Hardening Soil model, while reinforced concrete is modelled using the modified Lee–Fenves model enhanced by the Eurocode 2 (EC2)-compatible creep module, developed by the author. It is shown that the commonly used nonlinear soil–linear structure computational strategy may yield insufficient amount of reinforcement from the ultimate limit state (ULS) and serviceability limit state (SLS) points of view. A consistent and conservative method of combining fully nonlinear analysis and the rules imposed by the EC2 is proposed.

Danil E. Trapeznikov

The paleogeographic and tectonic conditions of the accumulation of Ufimian deposits (Lower Permian) were reconstructed on the basis of study more than 2000 wells within the Solikamsk depression. The most complete cross-section of the salt-marl formation (9 large layers of rock salt and gypsum rock) was studied. On this basis, the modified scheme of stratification of the salt-marl layer was proposed. The stratum was dismembered, both with complete and partial preservation of the salt layers. The stratum is divided into 3 large cyclothemes in this scheme, the cyclothemes - into series of cyclites. Each cyclite has a complete cycle of the evaporate sedimentation. The maps were constructed for each salt layer. The maps show the configuration of the salt lagoon and the migration of its depocenter within the Solikamsk depression (Ufimian age). The study of the cross-section shows the vertical change of the composition. The salt-bearing rocks are replaced by carbonate rocks - it corresponds to a general transgression in the region. For upper layers of salt-marl strata the facial replacement of the salt by gypsum rocks has been revealed. The analysis of the configuration of the reconstructed lagoon at the geological time demonstrates its connection with the regional tectonic events and salt tectonics in the Kungur sediments.

D. Vandine, S. McDougall, M. Jakob et al.

Zhongkui Li, Baoqi Lu, Jing Zou et al.

Xi Chang Xu, S. Chen, Lingfa Jiang

Based on a certain big site preparation project, the method to determine the dry density of filler for soil-aggregate mixture has been studied, and the characteristics of particle breakage after vibration is discussed. The results show that the surface vibration compaction method to determine the maximum dry density with mixture is suitable to soil-aggregate mixture. Considering the compaction factor of 0.94, the dry density control standard deducing from the maximum dry density is close to the projected field compaction test results. The particle breakage of soil-aggregate mixture during vibration is close to 20%, which shows that the particle breakage is significant. This study may have certain significance to similar projects. Introduction In recent years, the key construction projects in the central and western regions of China are having been more and more, such as the highways, railways, hydroelectricity, airports and nuclear power, which are mostly in mountainous area, facing the problems of large-scale ground leveling. In line with the principle of local materials and pollution reduction, the filler is mainly filled with excavation blasting stone, containing a small amount of coverage, which belonging to the earth and stone mix filler problems. In order to facilitate research, many scholars use the generalized definition of soil-aggregate mixture. Along with the improvement of the industry designation level, construction technology and the geotechnical tests level, the tolerated particle size of soil-aggregate mixture filler is increasingly growing, far beyond the range of coarse grained soil particle size, which belongs to the giant grain group category [1]. Particularly in some hydroelectricity projects, the maximum diameter of packing is up to 1m. Before the largely start of the filler construction, the filler control standards must be fixed, which mainly refer to the filler dry density. Generally control dry density is definite after the maximum dry density is determined by indoor test. Then determine the fill control dry density through combining between factor of compaction and field rolling test. The field construction parameters are often determined with combination of the rolling test in some roads, dams, large field flat engineering project filler. And then the large area construction is started, result in good achievements. In the field rolling test research, some experts have put forward the soil compaction quality should be controlled mainly to the settlement difference [2], based on the discussion of the compaction mechanism of coarse-grained soil in the high embankment reclamation engineering, and the different construction process parameters effect on construction effects ,such as packing gradation, moisture content and shop, rolling machine, the thickness of the soil compaction quantities and so on. And other scholars have also studied the field rolling test and the quality control standards, and have obtained some significant conclusions [3, 4]. The soil particle breakage is defined as the phenomenon that the structure of soil particles will be destroyed or damaged in the external load, and will split into equal or unequal amounts of particle size. However, soil particles are not compressed and broken based from classical soil mechanics. Granular soil particles broken engineering background is that the growing construction of international high buildings in the 1960’s, caused the large load of the foundation and the particle International Conference on Information Sciences, Machinery, Materials and Energy (ICISMME 2015) © 2015. The authors Published by Atlantis Press 83 breaking of quartz sand, gravel. In recent years, the effects of particle breaking are more and more remarkable with the construction of the large projects, especially the widely use of the soil-aggregate mixture. For example in the construction of Three Gorges project, the broken rate of filler materials weathered granite material sometimes reached 20%. And at present, people pay more attention to particle breakage phenomenon, especially the relationship between the particle breaking and mechanical characteristic. Zhang has presented study status of this paper comprehensively at home and abroad [5]. Yang guang have studied the particle breakage phenomenon under different stress path aggregates, and have found that the influence of stress path to aggregates of strength characteristics is not significant, but the improvement of the degree of particle breakage will decrease the peak internal friction angle [6]. Shi Xiu Song have studied the particle breakage fractal features of rock fill materials and have found that broken fractal dimension reflects the even degree such as the size and distribution of the particles breakage. The bigger fractal dimension is, the larger quantity of the particles breakage is [7]. Taking a large field flat project as background, combining with the rolling test, this paper analyzes the soil-aggregate mixture compaction characteristic and the indoor particle breaking characteristics, and has obtained the certain common conclusion to help establish and perfect the relevant industry sectors in the corresponding standard, expand procedure and promotion of soil-aggregate mixture in the application. Engineering background The project is a large-scale project mountain flat. Its excavation is about 18.29 million m3 conditions. Its filler is about 21.03 million m, and the filler height is mostly more than 20 m. The packing has complex lithology packing, and weathering degree is not uniform. The packing is comprised with four kinds, including the construction area packing as mixture of II, III kind. The II kind of material is the weak weathered gray matter conglomerate. The III kind of material is the strong and the moderately weathered conglomerate. All of them are made into the small broken stone through blasting, solution and other method. The construction area filler quality is the key point, and it is required that coarse material contents of mixture of II, III kind are at 70%, and its maximum diameter is no more than 300 mm. Energetically, particles that size > 5 mm are defined as coarse material, and size < 5 mm are defined as fine material. Laboratory experiment Experimental designs. Many experts have been carrying out theoretical and experimental studies in the maximum dry density of soil-aggregate mixture. Currently, as the theoretical research is lagging behind, the main method is through experiment. The experimental study included direct and indirect. The direct method is to enhance the performance of the instrument to determine the maximum dry density. Since it is limited by the performance of equipment and the range of particle size, the research progress of this method is slow. Indirect method used the existing test conditions. To extrapolate the maximum dry density of the filler prototype gradation, this method is based on measuring the relationship of the maximum dry density and particle size of coarse grained soil which can be measured in the size range. In recent years, the indirect method is developing well. Such as Yanwen Shi proposed the extension of a series of similar gradation[8], Shuyu Tian’s Asymptote assisted fitting[9], Qingguo Guo’s Three-point approximation of the Determination [10]. This paper sampled from the field and used the method of the extension of a series of similar gradation to determine the maximum dry density of the packing of the project. Soil samples preparation. Taking into account the variability of the packing, we sample from the loose overlay directly and excavate test pits in the construction of the two different filler area. The diameter of these pits range at 1m and the depth is the thickness of the loose overlay. The sample less than 60mm is shipped back to the laboratory from screening in the field and labeled 1# and 2# (all of them are mixture) respectively.