Simple Method for Incorporating Lateral Wheel Wander in the Computation of Fatigue Damage in New Flexible Pavement Structures

2020 ◽  
Vol 146 (4) ◽  
pp. 04020074
Author(s):  
Ana Maria Coca ◽  
Stefan A. Romanoschi ◽  
Mohsen Talebsafa ◽  
Constantin Popescu
2012 ◽  
Vol 594-597 ◽  
pp. 1445-1448
Author(s):  
Tao Cheng ◽  
Ke Qin Yan

Mechanics properties of lime- fly ash stabilized soil are investigated. First, the chemical composition of fly ash are analyzed by spectral analysis test. Compaction experiments of all mix proportion projects are carried out in different water conditions to obtain the optimum water contents. Then the optimum mix proportion is obtained by the unconfined compressive strength and the compression rebound modulus test. Finally, the pavement structures design for a highway of lime- fly ash stabilized soil road sub-base is done. By the comparison, a conclusion can be drawn that lime-fly ash stabilized soil is suitable for flexible pavement or semi-rigid pavement because of its good strength and rigidity which can effectively reduce thickness of the lower pavement and basic deflection.


2021 ◽  
Vol 4 (1) ◽  
pp. 109
Author(s):  
Verell Rengga Harsvardan ◽  
Anissa Noor Tajudin

This research will redesign the flexible pavement on the Kalihurip-Cikampek toll road using three flexible pavement design methods, namely the 2002, 2013 and 2017 methods, and analyze the structural responses that occur in the form of horizontal and vertical strain, the main components. In calculating the value of repetition of permits against fatigue damage (Nf) and groove cracks (Nd), it is processed using the KENPAVE program. Furthermore, the calculation results of the flexible pavement thickness, the value of repetition of permits against fatigue damage (Nf) and groove crack damage (Nd) were compared from the three methods. The method used is mechanistic-empirical. Primary data is obtained from the Ministry of Public Works and Public Housing and LHR0 starting in 2020, taking into account traffic growth from 2020 to 2035, as well as secondary data assumptions by referring to previous regulations and research. The results of this study indicate that the 2002 method produced the largest pavement thickness, while the 2013 and 2017 methods produced relatively the same pavement thickness. However, the 2002 method produced the largest repetition of permits against fatigue damage (Nf) and groove cracks (Nd). So it can be concluded that the 2017 method produces a better design. ABSTRAKPenelitian ini akan mendesain ulang perkerasan lentur pada Jalan Tol Jakarta-Cikampek ruas Kalihurip-Cikampek menggunakan tiga metode desain perkerasan lentur yaitu metode 2002, 2013, dan 2017, serta menganalisis respons struktral yang terjadi berupa regangan horisontal dan vertikal, komponen utama dalam menghitung nilai repetisi izin terhadap kerusakan fatik (Nf) dan retak alur (Nd), diolah menggunakan program KENPAVE. Selanjutnya dibandingkan hasil perhitungan tebal perkerasan lentur, nilai repetisi izin terhadap kerusakan fatik (Nf) dan kerusakan retak alur (Nd) dari ketiga metode tersebut. Metode yang digunakan mekanistik-empiris. Data primer didapat dari Kementerian Pekerjaan Umum dan Perumahan Rakyat (PUPR) dan LHR0 dimulai pada tahun 2020, memperhitungkan pertumbuhan lalu lintas dari tahun 2020 sampai 2035, serta data sekunder asumsi dengan tetap mengacu pada peraturan dan penelitian sebelumnya. Hasil penelitian ini menunjukkan bahwa metode 2002 menghasilkan tebal perkerasan terbesar, sedangkan metode 2013 dan 2017 menghasilkan tebal perkerasan yang relatif sama. Namun metode 2002 menghasilkan repetisi izin terhadap kerusakan fatik (Nf) dan retak alur (Nd) terbesar. Sehingga disimpulkan metode 2017 menghasilkan desain lebih baik.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Song Yang ◽  
Bing Qi ◽  
Zhensheng Cao ◽  
Shaoqiang Zhang ◽  
Huailei Cheng ◽  
...  

The strain responses of asphalt pavement layer under vehicular loading are different from those under falling weight deflectometer (FWD) loading, due to the discrepancies between the two types of loadings. This research aims to evaluate and compare the asphalt layer responses under vehicular loading and FWD loadings. Two full-scale asphalt pavement structures, namely, flexible pavement and semirigid pavement, were constructed and instrumented with strain gauges. The strain responses of asphalt layers under vehicular and FWD loadings were measured and analyzed. Except for field measurements, the finite element (FE) models of the experimental pavements were established to simulate the pavement responses under a wide range of loading conditions. Field strain measurements indicate that the asphalt layer strain under vehicular loading increases with the rising temperature roughly in an exponential mode, while it decreases with the rising vehicular speed approximately linearly. The strain pulses in the asphalt layer generated by FWD loading are different from those induced by vehicular loading. The asphalt layer strains generated by FWD loading are close to those induced by low vehicular speed (35 km/h). The results from the FE model imply that the asphalt layer strains under FWD loading and vehicular loading are distributed similarly in the depth profile. For flexible pavement, the position of critical strain shifts gradually from the bottom of the asphalt layer to the mid-depth of the layer, as the temperature increases. For semirigid pavement, the position of critical strain is always located at the intermediate depth of the asphalt layer, regardless of temperatures.


Author(s):  
T. F. Fwa ◽  
Thakur Swapna Rani

The seed moduli chosen for backcalculation analysis of multilayer flexible pavements can have significant impacts on the performance of backcalculation software and, sometimes, the final solutions of the backcalculated moduli. Practically all backcalculation programs provide internally generated seed moduli for backcalculation analysis. However, as the internally generated seed moduli do not always produce satisfactory results, the use of user-input seed moduli is generally encouraged. With the aim of providing useful guidance in the choice of seed moduli, a seed modulus generation algorithm, 2L-BACK, for multilayer flexible pavements based on a closed-form modulus backcalculation solution for two-layer flexible pavement structures was developed. The proposed algorithm does not require any subjective judgment by the user. An evaluation analysis of the effectiveness of the proposed procedure is presented by the use of two types of backcalculation software, MICHBACK and EVERCALC, and is based on measured and computed data for flexible pavement segments from the Long-Term Pavement Performance project. A comparison was made of the backcalculation program performance and the computed moduli of solutions obtained from internally generated seed moduli and those obtained from seed moduli generated by the proposed algorithm. It was found that the proposed seed modulus generation algorithm led to enhanced program performance of MICHBACK with respect to convergence characteristics and the accuracies of the backcalculated solutions. In comparison, the corresponding improvements for the case of EVERCALC were less. The proposed seed modulus generation algorithm does not suffer from the location and pavement type transferability constraints of most regression-based seed modulus generation methods. The results of the study suggest that the algorithm can be effectively incorporated into backcalculation software for multilayer flexible pavements.


Author(s):  
Mamadou Badiane ◽  
Junyan Yi ◽  
Guy Doré ◽  
Jean-Pascal Bilodeau ◽  
Fritz Prophète

Author(s):  
Kenneth Kirkpatrick ◽  
Christopher R. Johnson ◽  
J. Adin Mann

Abstract ASME Boiler and Pressure Vessel Code (BPVC), Section VIII, Division 2, Part 5 Method B fatigue screening is intended to be a quick and simple method that is sufficiently conservative to screen components in cyclic service thus not requiring detailed fatigue analysis. The method assesses pressure, thermal, and mechanical loads separately. The basis for each portion of the method is discussed along with an alternative bases for the assessments. Each assessment is reformulated as a fatigue damage factor and all variables are provided so that the intent of each equation is clearly identifiable. A penalty factor will be included in each equation rather than assuming one penalty for all designs, the reformulation creates penalty for non-fatigue resistant designs and reduces the penalty for fatigue resistant designs. Examples are given showing the potentially non-conservative results if a summed damage is not used.


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