The type of trap is the large - sized lithologic trap showing a north - south extent band 气藏类型为南北向条带状发育的大型岩性圈闭。
In research area , yanchang 4 + 5 sector to yanchang 3 underwater distributary channel sandbodys in delta front was north - east to south west , and were separated by interdistributary bay 研究区长4 + 5 ?长3期三角洲前缘水下分流河道砂体均呈北东?南西向条带状展布,砂体之间被分流间湾分隔。
3 . based on the assumption of general slip surface , a general formula of safety factor of slope is presented in which the forces exerted on the slices exactly satisfy the equilibrium condition . using the method the chapters introduced to search critical slip surface , and proved by examples , this method is more reliable , and can search , simulate the critical slip curve 推导出了滑动面为任意现状,边坡体内作用有各种荷载且满足力平衡条件下的边坡稳定系数计算公式(在进行条分计算时,假定条间仅有水平方向作用力,竖向条间剪力为零) ,利用本文提出的遗传进化搜索方法搜索边坡最危险滑动面。